Plumbing 4oUSEHOLD§ AN ITATIOfJ * • * 4nJlqjk%^Maq)a3a^ * 1 i— i lip || |fo1 • Plumbing and Household Sanitation. boldly forward on firm ground to the goal of perfect sani- tation. Let us, therefore, go with the biologist into, his laboratory for a while and view with him the marvels of the micro- scopic world, the little beings upon whose activity all life on our planet depends, the agency through which new life returns from death ; the silent, untiring builder, infinitesimal and impotent as a single individual, but gigantic and irre- sistible as a collective force. The word "bacterum" or "microbe" means to most people, even today, something terrible and destructive, because only within the last few years have we learned the vastly greater importance of these organisms for good than for evil, and see in them our indispensable friends. There are black sheep among them, but they are as few, comparatively, as the criminals in human society who constitute the "rogues' gallery." There is no family of visible plants which begins to compare with these microscopic ones in importance. Although there are now known to be several hundreds or perhaps even thousands, of different species of bacteria, they have only a few general forms which correspond respectively to spheres, rods, and spirals. Our Fig. 28* il- lustrates all of these forms. At the top we see in Figs. 1 to 5 of the plate, the spherical bacteria, called micrococci. Al- though they all look alike, they are nevertheless all of en- tirely different species, those in Fig. 2 being disease germs, and the remainder being germs of fermentation. Fig. 6 is a yeast bacterium which forms the beautiful rose- colored patches on cooked potatoes. Next below come the rod formed bacteria, Figs. 8 to 16, some of which are in process of division into shorter pieces, the usual method of multiplication of bacteria. Those in Fig. 10 come from the ♦From "The Bacteria," by Dr. Antoine Magnin, translated by Dr. G. M. Sternberg. 50 Bacteria. Fig. 28. Bacteria. surface of sour beer. The remaining figures show the spiral bacteria. Fig. 17 is named in this plate as the "vibrio ser- 51 Plumbing and Household Sanitation. pens," and Fig. 21 the "spirillum volutans." Fig. 19 the "spirillum tenui," single and felted into "swarms." All these organisms are far too minute to be visible to the naked eye. The spheres vary from one to six one-hun- dred-thousandths of an inch in diameter, and the rods and spirals have a thickness about the same as the diameter of the spheres, and a length varying all the way from a little more than their thickness up to long threads of a thousandth of an inch or more. Frankland,f speaking of the size of bacteria, says we could have a population of them one hundred times as great as that of London settled on a single square inch, without any complaint of overcrowding, but giving each individual organism one four-hundred-millionth of a square inch of space, which is quite adequate for a citizen in the common- wealth of these Liliputians. It is in their enormous and almost incredible power and rapidity of multiplication that their importance lies, some species having been observed under the microscope to di- vide every half hour or less. They infest all our surround- ings, entering our nostrils with every breath we take, swim- ming in every draught of water, and are in full possession of every inch of ground we stand upon. They do not, however, descend to very great depths in the soil, few existing, according to Prof. Conn,J below four feet. At the surface they are very abundant, and if the ground is moist and full of organic material the number may range here from a few hundred to several millions per grain. In the ocean they are found at all depths within a hundred miles from the shore, as well as in the sediment at its bed. At the rate of reproduction observed, each bac- terium would have over sixteen million descendants in a f'Our Secret Friends and Foes," by P. F. Frankland. 1H. W. Conn, "The Story of Germ Life." D. Appleton & Co., N. Y. 52 Bacteria. day, and over 281 billion in two days, aggregating in weight about a pound. At the end of the third day, if the process were uninterrupted, the descendants would weigh about 16 million pounds, and in five days they could, if properly nourished, fill the entire Atlantic ocean solid full. Fortu- nately, however, Nature supplies the bacteria with a num- ber of enemies most wonderfully adjusted to keep them within proper bounds. Now this marvelous power of growth is chiefly due to a fact which gives the bacteria their extreme importance in Nature, especially to the sanitary engineer. Other plants require simple substances like carbon dioxid (C0 2 ) and water for their nourishment, but the bacteria are able to feed upon the complex organic material of animal and plant structure. They tear this structure after death to pieces, chemically speaking, and prepare it for new forms of life. The discovery of the conditions under which this is done is revolutionizing the science of sewage disposal.* Some species of bacteria have, in addition to the power of reproduction by simple fissure, a second method by means of spores which develop within them, and the man- ner in which the spores grow serves as one of the points by which the different species of bacteria are distinguished from one another. The spore serves the purpose of keeping the species alive under conditions of adversity, through its wonderful power of resisting extreme heat (in some cases for a short time, even above that of boiling water), severe cold, desiccation, and all sorts of rough usage, which would speedily destroy the parent germ. Indeed they are, says Frankland, ''the hardiest forms of living matter which science has yet revealed." *See Frankland and Conn, from whom the facts in some of these passages relative to bacteria have been taken, and even in part, in a few cases, the wording itself, to some extent interspersed with my own. 53 Plumbing and Household Sanitation. Some, but by no means all, species of bacteria have the power of active movement, the study of which forms one of the most fascinating microscopic spectacles which exist. 'The varied motion," says Frankland, "of the countless swarms of individuals following their sinuous paths across the field of the microscope, in all directions, and in the three dimensions of space, much after the fashion of a cloud of midges playing in the sunshine, produces an irresistible im- pression upon the observer, that each individual microbe is assisting in and conscientiously performing its part in a highly complex and thoroughly organized Scotch reel, con- ducted at express speed." This motion is supposed to be produced by flagella, which lash the liquid with great activ- ity and give the plants so strongly the effect of animals that it is almost impossible to believe what the authorities tell us of their being among the lowest forms of simple vege- table life similar to the oscillaria or green thread-like plants known to the botanists. Before studying the action of bacteria in their role as sanitarians and fertilizers of the soil, it is important to say a word as to their use in the arts. Many important indus- tries are now known to be absolutely dependent upon them as agents of fermentation and decomposition. Sometimes they split up the molecules of the substances upon which they act into simpler molecules and sometimes they build them up into more complex ones, in all cases changing their chemical natures, and thereby forming numerous useful products which could not exist without them. The world is only beginning to realize their tremendous usefulness in these ways. There are, in the first place, many industries which may be classified as maceration industries, or based on the de- composition powers of bacteria. Hardly any organic sub- stance is able to resist their softening influence, and man 54 Bacteria. has taken advantage of this power in many arts. Thus linen, jute, hemp, and other vegetable fibrous growths re- quire fermentation to free the valuable fibers from the woody parts with which they are associated in nature. Aided by moisture and the proper temperature the bac- teria soften the fibers and thereby permit of the separation of the useful from the useless parts. This so-called "retting" process is not allowed to continue long enough for the bacteria to injure materially the valuable fibers, but only long enough to facilitate their dissolution from the rest. The preparation of sponges for use is also accomplished by bacteria. They decompose the soft tissues constituting the body of this marine animal so that it can be removed by washing from the skeleton, which forms the sponge of commerce. Leather is prepared for the tannery by bac- teria. The hide with the hair on it is steeped in warm water until partial decomposition enables the hair to be easily removed with a knife. The manufacture of citric, lactic, butyric acid, vinegars, indigo, tobacco, opium and many other substances is accomplished by the aid of bac- teria in producing fermentation. In all of these processes a different species of bacterium does the work, the proper kind appearing, by some wonderful provision of nature, immediately when the proper conditions are provided for it. They seem to be ever on the alert to serve us, and hasten to the spot where needed and there multiply with marvelous rapidity until the number of workers required to accomplish the desired result in the best manner and shortest time possible has appeared. Butter and cheese making can only be accomplished by the aid of bacteria of various kinds, and it is probable that any desired flavor will be produced by the scientific dairy- 55 Plumbing and Household Sanitation. man of the future by cultivating and introducing the spe- cial kinds of bacteria which experience teaches will yield the desired result. We come now to the species of bacteria most interesting to the sanitary engineer, to those which provide plants and animals with food during life and take care of them after death. Upon these all life on the globe is dependent and would cease if their labors were suspended for any consid- erable length of time. Plants and animals both require food, but while animals can live upon plants, plants are unable to obtain their en- tire nourishment directly from animals or other plants. Their elements must first be taken apart in order to pro- vide food simple enough for continuing their life, and these simple products must be restored to the earth, which would otherwise soon be exhausted of its plant food in- stead of remaining year after year for untold ages as fertil- izers. All this is done by bacteria. Moisture alone is not able to disintegrate the hard trunks of trees and the bodies of animals when they die. It could not soften their tissues and convert them to gases and elements suitable for plant food. Were it not for bacteria, which alone possess this power, the earth would soon be completely covered with dead bodies, leaving no possible room for further growth of plants and animals. This bacterial action is what is known as decay, and it is called "decomposition" when it takes place in the presence of oxygen, and "putrefaction" when oxygen is debarred. Sanitary engineers have just begun to learn the vast difference between these two forms of decay and to put their knowledge to practical use in their systems of sewerage and plumbing. They have learned that entirely different species of bacteria are employed in these two processes, and that upon their success in cultivating the one or the other depends the value of their efforts. 56 Bacteria. Fig. 29 shows the cycle of life and the part played therein by the different kinds of bacteria. At the bottom of the circle is mother earth. It contains some of the principal ingredients which form the food of plants, and above all compounds of nitrogen called nitrates. Carbon dioxid and water are also required by plants and these are obtained partly from air. Other compounds in the soil which plants use are salts of potassium, phosphorus and some other elements, but these are here omitted for simplicity as of less importance in this connection. The roots of the plants shown on the earth at the left take up the nitrates from the soil, and their leaves absorb the gases from the air, and with the energy furnished by the sun's rays build these simple compounds into more complex ones shown in the circle above the plants as the second step. They are sugar, starches and fats, forming the complex food required by the animal kingdom, indi- cated by the figures of a man and a horse at the top of the cycle. Some parts of these foods are at once decomposed by the animals and given back to the air from their lungs and pores in the form of carbonic acid and water, and we have shown these in our picture by dotted lines returning at once again to the plants at the bottom. But this quick return does not occur with the nitrogenous foods. These require further treatment and must continue around the circle of changes, forever repeated in nature's great labor- atory. Animals build these nitrogenous foods into new albumens, reducing part directly into urea, which is ex- creted. But a plant can neither feed directly either upon the nitrogen compounds stored in the bodies of the animals nor upon those which are thrown off by them during life. It cannot feed upon the flesh, fat, bones nor excreta which *I am indebted to Prof. Conn for the idea of representing Nature's food cycle graphically, but the special design is my own. 57 Plumbing and Household Sanitation. constitute the products of animal life as shown in our pic- ture at the right of the animals. They must be reduced to simpler forms, and the third step in the food cycle is taken by the decomposition bacteria. The animals have died, as we see, and the bacteria are already engaged in their work as scavengers. Our drawing shows, at each step, the particular form of bacterium actually found at work at that stage, and copied from life, as revealed by the microscope, and in the four outer corners we have reproduced photo- graphs of the four principal types of bacteria most inter- esting to us in this connection as sanitary engineers. You see, therefore, thrown upon the screen, individual mem- bers of this valuable community as they actually appeared while engaged in their great work of food preparation and sanitation. Only they are here magnified by the electric rays to several hundred thousand times their real dimen- sions. They are our great little co-workers, the faithful engineer's assistants, the patient, industrious, eager, non- complaining plumber's helpers. We may take a lesson from these helpers in their unceasing, ever-cheerful toil. u Ever at toil," they bring "to lovliness All ancient wrath and wreck." These organisms exist in the air, soil and water, always on the alert for any organic substance requiring their pres- ence, and no sooner is it provided, instantly, as if by magic they appear and begin to break it up for plant food ! A portion of these cleavage products takes the form of car- bonic acid gas and water, which are dissipated in the air and return at once, as shown by the dotted lines, to the plant. But the other portion, containing nitrogen, is broken up into ammonia, N K 3 , or into compounds called nitrites. But these are too simple for plant food. The chemical destruction by this particular detachment of helpers has 58 Bacteria. 1 m ' ?' t ^ automatically deposited partly 'by bac ESS aC Tn S'*i nd *? rapi t mecha ™al filtration it s hemic y precipi- lli^tl ^ both systems the amount of the coating must be periodicaSy fatSn n? VL° rder to + maintain th * P^per speed of filtration P Th£ reg£ latum of the amount of coating, which is sometimes called the ''dirt « on er o? g « flTtP sch f utz ^," forms the most costlyVr? o ? the op Na- tion of a filter A number of plans for reducing this expense are now eXir^r^iWation.'! 011 ° Be "* the WHt " fi ootllnSTn T iStS 108 Experiments on Filtration. free entrance into houses built upon them of these organ- isms which smarm in the ground-air around leaching cess- pools, leaky drains, etc., or in the filthy made-ground of cities. Fig Long- coil of pipe filled with sand. "And from the results obtained from the two series of experiments, viz., in filtering air and in filtering water, we can now draw one very important practical conclusion which cannot be too strongly emphasized. That a house may be built on a thoroughly dry body of sand or gravel, and its cellar may be far above the level of the ground-water at all times, and it may yet be in danger of having the air of its rooms contaminated by germs from leaching cesspools and vaults ; for, if the drift of the leaching be toward the cellar, very wet seasons may extend the polluted moisture to the cellar walls, whence, after evaporation, the germs will pass into the atmospheric circulation of the house." 109 CHAPTER VI. Micro-Organisms in Sewer Air. The methods for the study of micro-organic life in air are of compar- atively recent date and are daily being improved. According to Roechling about six sets of investi- gations into the bacte- rial flora of sewer air have within recent years been made, and from them in complete cor- roboration of other re- searches made before by less perfect methods and apparatus. They show that sewer air contains few germs as compared with outer air, sewer air containing on the average from 2 to 9 germs where outer air contained 15 per quart. These germs are related to the germs of the outer air, but not to the sewage itself, which contain an enormous number of germs, a quart con- taining sometimes as many as 5 billion. Disease germs are not found in sewers with the single exception of the germ of suppuration (staphylococus pyogenes aureus) and up to the present time* only one of the many observers (Uffel- mann) has been able to discover even this pathogenic germ *This was written before the experiments of Major Horrocks had been made. 110 Micro-Organisms in Sewer Air. in sewer air. Splashing of sewage, as when a branch sewer enters another or a main sewer with a high fall, may cause a fine state of division of sewage in virtue of which germs may be carried some distance through the air, "even 50 or 60 yards" according to Laws, from which our remedy lies in so arranging the connections as to avoid splashing. If the sewage falls against the inner curved surface of the drain it may be arranged to do this without splashing even from a considerable height. The experiments of Laws showed that a branch drain emptying its sewage into an egg-shaped sewer 11 ft. high by 9 ft. wide from about the middle of its height produced practically no effect upon the number of micro-organisms in the sewer air. The experiments of Laws in London and Ficker in Bres- lau seem to show that germs cannot be given off from the slimy skin which forms on the inner surface of sewers on account of the dampness of the air in them. Mr. Laws says in regard to this: "It is really remarkable to find that no organisms are given off from the walls of a sewer which has been empty and open to the air at both ends for such a lengthened period as 12 days. The sewage with which the sewer had been kept full for several periods of 24 hours would contain no less than three to four millions of organ- isms per cubic centimeter (about ^ in. cube) and immense numbers of these must of necessity have been clinging to the walls of the sewer. . . . The velocity of the air current used in the above experiments was 5 ft. and 15 ft. per sec- ond, respectively, the latter being far in excess of any cur- rent that would normally obtain in a sewer." Ficker found that a current of air of several yards a second could not lift up germs from a hal'f moist soil, nor even germs which had dried on several substances and ad- hered to them. Hesse experimented to see how far germs could be car- ill Plumbing and Household Sanitation. ried in air currents in pipes and sewers before falling against and adhering to their sides. In one experiment with a 2-in. pipe a yard long, coated with nutritive gelatine, he found that the air current deposited a large number of bacteria on the first quarter, less on the second, still less on the third, none at all on the last quarter. Ficker experimented in this line with 4-inch pipes and found the germs were carried as much as 23 feet. Disease germs find the conditions in the sewers unfavor- able to their life and propagation. They cannot survive against the myriads of other germs that crowd the sewage and in their slow death in fighting against these they gradu- ally lose their virulence or power for mischief long before their actual death takes place. Kirchner says : "We are entitled to say with a probability bordering on certainty that presumably pathogenic germs will never be found in sewer air." Messrs. Laws and Andrewes went so far as to classify elaborately and comparatively the various kinds of germs found in the outer air, in sewer air and in the sewage itself, and they found the same kinds in sewer air as in the outer air, but a totally different kind in the sewage. They even go so far as to say that so far as they are aware, not a single colony of any of the many species which they found predominate in sewage has been isolated from sewer air. These investigators even assert that "moderate splashing carried out so as to imitate the inflow of a lateral drain or house sewer produces no variation in the sewer air even within such a short radius as four feet from the disturb- ance." In view, however, of the absence, still, of accord on this point among all investigators, it is well to avoid such splashing as far as possible. As for the typhoid fever germ, how very difficult it is, to catch it, even in sewage, is clear, says Mr. Roechling, from 112 Micro-Organisms in Sewer Air. the report of Messrs. Laws and Andrewes. Although they used the greatest care, they were not" able to find this germ once, in ordinary London sewage. Even in the typhoid fever hospital drain inside the hospital grounds, they were able to find only two colonies, and in this drain a quarter of a mile away not a single typhoid germ was found. They probably were killed by other bacteria who were their ene- mies and vastly exceeded them in numbers ; for many harm- less germs thrive in sewage, as disease germs appear not to. Accordingly from all these investigations we may con- clude that the cases of typhoid fever and other diseases to which we have alluded were not due to disease germs entering the houses in the air of the sewers, but to contami- nation of the food or water supply by sewage polluted water, or by insects, especially house flies, passing from infected substances to the food or bodies of the inmates, the sewer air simply predisposing the system to infection. A few words now about different methods of sewage dis- posal are necessary to enable us to treat intelligently the house plumbing connecting with and dependent upon it. Mr. Roechling** well defines "decomposition" as the process of complete oxidation or mineralization, in which the organic matter in the presence of an ample supply of oxygen is converted into its new compounds of water, car- bonic acid, nitrous and nitric acids without the creation of foul smells; and "putrefaction" as the process of incom- plete oxidation, in which, in the absence of oxidation, foul smells are produced "which poison the atmosphere." Decomposition is conducted by the "aerobes," bacteria which can only exist in the presence of oxygen, but putre- faction with its foul and injurious smells is accomplished by ••"Sewer Gas and Its Influence Upon Health." H. Alfred Roech- ling. Biggs & Co., London, 1899. 113 Plumbing and Household Sanitation. hordes of aenaerobes who "finally perish in the ever increas- ing carbonic acid or in other substances of their own mak- ing. It is stated that the number of bacteria of decomposition which are found in the average dejecta of an adult male exceeds thirty thousand millions, and it is held that, where disease germs exist among these, they succumb after a short struggle for existence with the swarms of the aerobes. A properly constructed system of sewers is one which delivers all waste matters at the sewer outlet in a fresh .con- dition, that is in a condition in which they might flow through a perfectly smooth and well washed street gutter without attracting attention by their odor. The sewers must be thus constructed and as free from odors as such a street gutter. To accomplish this, all unscoured areas or chambers in the drainage system and foul dead ends of every descrip- tion in the house or out of it, must be avoided as centers of putrefaction. VIEWS OF OTHER AUTHORITIES. Dr. A. Jacobi in a paper read before the Congress of American Physicians and Surgeons at Washington as early as 1894, sums up as follows : "I may be finally permitted to add the oral testimony of more than a dozen European medical men and dozens of Americans. Every one was asked by me : What do you know of the production of a specific germ disease out of, or through, sewer air? The uniform answer was: There is a general vague impression among the public, but I never saw a case or could prove one. Some of the conclusions to be drawn from this paper would be as follows : The atmosphere contains some specific disease germs, both living and dead. 114 Micro-Organisms in Sewer Air. They are frequently found in places which were infected with specific disease. In sewer air fewer such germs have been found than in the air of houses and school rooms. Moist surfaces — that is, the contents of cesspools and sewers, and the walls of sewers — while emitting odors do not give off specific germs even in a moderate current of wind. Splashing of the sewer contents may separate some germs, and then the air of the sewer may become temporarily in- fected, but the germ will sink to the ground again. Choking of the sewer, introduction of hot factory refuse, leaky house drains and absence of traps may be the causes of sewer air ascending or forced back into the houses. But the occurrence of this complication of circumstances is cer- tain to be rare. Whatever rises from the sewer under these circumstances is offensive and irritating. A number of ailments, inclusive, perhaps, of sore throats, may originate from these causes. But no specific diseases will be generated by them except in the rarest of conditions, for specific germs are destroyed by the process of putrefaction in the sewers, and the worse the odor the less the danger, particularly from diphtheria. The causes of the latter disease are very numerous, and the search for the origin of an individual case is often un- successful. Irritation of the throat and naso-pharynx is a frequent source of local catarrh ; this creates a resting place for diphtheria germs, which are ubiquitous during an epidemic, and thus an opportunity for diphtheria is furnished. Of the specific germs, those of typhoid and dysentery appear 'to be the least subject to destruction by cesspools and sewers. These diseases appear to be sometimes refer- able to direct exhalation from privies and cesspools. Very few cases, if any, are attributable to sewer air. 115 Plumbing and Household Sanitation. A single outlet from a sewer would be dangerous to gen- eral health because of the density of odors (not germs) aris- ing therefrom. Therefore a very thorough and multiple ventilation is required.* The impossibility or great improbability of specific dis- eases rising from sewers into our houses, protected as they are, or ought to be, by good drains and efficient traps, must, however, not lull our citizens and authorities into indolence and carelessness. For the general health is suffering from chemical exhala- tions, and the vitality of cell life and the powers of resist- ance are undermined by them." Naegeli experimented by enclosing putrescent and putres- cible liquids in sealed vessels together for over three years without air infection taking place, and by drawing air through sand wetted with putrescing liquid and then through sterile infusion without infecting the latter. Sir Edward Frankland of England found that "the mod- erate agitation of a liquid does not cause the suspension of liquid particles capable of transport by the circumambient air/' but that "the breaking of minute gas bubbles on the surface of a liquid consequent upon the generation of gas within the body of the liquid is a potent cause" of such suspension, and that therefore the stagnation of sewage or constructive defects in sewers may form cesspools of putre- faction in the sewers and generate gases which may form these bubbles. Such defects in sewer construction are totally unnecessary, and cesspool accumulations should, as I have said, never be allowed. In 1883 P- Miquel* published the results of his experi- ments on the comparison between sewer and street air in *"The Sidewalk Ventilators in New York City are almost all obstructed." *"Les Organismes Vivants de l'Atmosphere," Paris. 116 Micro-Organisms in Sewer Air. Paris, and from 1893 to 1899 ne made periodical tests which were given in the following table : BACTERIA IN COUNTRY AIR, CITY AIR, AND SEWER AIR, PER CUBIC METER. Country Air. City Street. Year. Montsouris. Hotel de Ville. Sewer Air. 1893 285 8,435 5PI5 1894 230 9,775 2,920 1895 330 7^15 2,590 1896 6,205 3,965 1897 197 5,4io 3,875 1898 5,200 2,075 1899 6,595 2,910 Uffelmann experimented with a house drain in 1886-7, taking nine samples at intervals during a year. He found an average of 3 bacteria per liter of sewer air. Petri found 1 bacterium and 3 molds in 100 liters of air in a Berlin sewer on one occasion and no bacteria and 1 mold on another. Carnelley and Haldane* made important studies on sewer air in England in 1887. They found less bacteria in the sewers than in the streets in almost all cases, averaging 9 per liter in the former and 16 in the latter. They conclud- ed that *'The micro-organisms in sewer air come entirely, or nearly so, from the outside, and are not derived, or only in relatively small numbers, from the sewer itself." They found a considerable increase, however, under violent splash- ing. They found less bacteria in the air in contact with quietly flowing sewage rather than more, on account of the wet surface. Robertson** found less bacteria in the air of the sewers *T. Carnelley and J. S. Haldane. "The Air of Sewers," proceed- ings of the Royal Society of London, 1887, XLII, pp. 394 and 501. **"A Study of Micro-Org-anisms in Air. Especially Those in Sewer Air, and a New Method of Demonstrating Them." British Med. Journal, Dec. 15, 1888. 117 Plumbing and Household Sanitation. of Penrith than in the street air, averaging 4 to 6 respec- tively. More bacilli were found in the former and more cocci in the latter. Laws found that even splashing in sewers was unlikely to produce appreciable infection, and that sewage falling into an egg-shaped sewer, 11 ft. x 9, from the middle of its height, produced practically no effect on the number of germs. J. McG. Smith (Sixth Annual Report of the Metropolitan Board of Water Supply and Sewerage, 1893) found as an average of 20 tests 225 germs per liter in the sewers of Sydney, the particular forms being without exception organ- isms common in street air. In 1894 Dr. A. C. Abbott of Philadelphia found germs were transported on a current having a velocity of 16.5 cm. per minute, but not by one of 8.6 per minute or less. Dr. Abbott's conclusions were that the danger of bacteria being transmitted under natural conditions was practically negli- gible. Dr. Charles Harrington* says "The majority and the best of German investigators, such as Fliigge, Rubner, Gartner, Soyka, Prausnitz, and others maintain that sewer air and sewer gases are quite incapable of conveying the germs of typhoid fever and other infective diseases. It is true that some of the gases given off in the putrefaction processes which go on in sewers are more or less poisonous, but whether they are capable of producing any injurious defects depends very much on the amount inhaled and on the degree of concentration. In any event they are certainly incapable of producing any infective disease in the absence of the specific germ." Mr. Allen Hazen writes that Col. Ruttan has "investigat- ed the plumbing in a considerable series of houses in Win- ■A Manual of Practical Hygiene, Phila. and N. Y., 1901. 118 Micro-Organisms in Sewer Air. nepeg with the general result of finding that plumbing is not associated with typhoid fever. In fact his statistics show a somewhat larger proportion of cases of typhoid fever in the houses where the plumbing is good, than in those places where it is defective." Mr. Hazen sums up the best current American opinion in the following sentence "After many years of experience and long continued investigation there is not the slightest reason to believe that infectious diseases are carried by the air of sewers."* G. C. Whipple** says "Typhoid germs do not readily leave a moist surface. Sticky by nature they adhere until desiccation loosens their dead cells. For this reason sewer air is not to be looked upon as a direct means of infection." In 1907 Major W. H. Horrocks* of the Royal Army Medical Corps of Great Britain in some analyses of sewer air at Gibraltar found under certain conditions germs car- ried from the sewage into the air. His principal deduction from these tests was stated as follows : "Specific bacteria present in sewage may be ejected into the air of ventilation pipes, inspection chambers, drains and sewers by (a) the bursting of bubbles at the surface of the sewage, (b) the separation of dried particles from the walls of pipes, cham- bers, and sewers, and probably by (c) the ejection of minute droplets from flowing sewage." This paper created some excitement among sanitarians in the world, and caused many to return almost to the old time terror of "sewer gas." But closer examination of the experiments of Horrocks and of his summary of conclusions does not appear to jus- •Engineering News, L.III, 246. **ln the latest American Text Book on Typhoid Fever (Typhoid Fever, New York, 1908). ♦Proceedings of the Royal Society, Series B, Vol. LXXIX, No. E 631. p. 255. Feb. 7. 1907. 119 Plumbing and Household Sanitation. tify any such alarm. These conclusions as stated by himself were only such as had practically been admitted by previous investigators we have already quoted. In some of his experiments Major Horrocks used strongly foaming soapy solutions and vigorous splashing resulting in the ejection of a few germs (B. prodigiosus) from the sewage in the same way with other investigators. In an- other case he obtained a few germs from quietly flowing sewage. But this again had been observed by others and ascribed to the drying of sewage on the sides of the pipes, or from the transmission through it of fine bubbles caused by decomposition or chemical action in the sewage. Certain germs are known to dart rapidly through the fluids in which they exist under the action of flagella, celia or whips at- tached to their bodies. Others have a slow serpentine, spiral or creeping motion and it might, at first thought, seem pos- sible for the swiftly darting kinds to leap out of the water like a flying fish and thus escape into the air. A flying fish can leap from the water and remain a few moments in the air. But the germ has not the peculiar muscular, flexible, and springy body, fins and tail of the flying fish. The long flagella of the germ presents precisely the construction which would prevent aerial flight especially when heavy with water soaking. Cuttle and jelly fishes more nearly resemble the flagellated bacteria and these do not fly about in the air. To expect such action on the part of even the swiftest darting germ would be as reasonable as to expect to see a devilfish paddle himself with his long tentacles up to the surface of the ocean and soar away above the clouds. Mariners have not as yet recorded having seen this feat and microscopists are as little likely to have to tell the tale about disease germs. That germs do not progress by their own motive power through air was indicated by Pasteur when he proved that it was not necessary to insist upon hermetic sealing or cotton 120 Micro-Organisms in Sewer Air. filters to keep them from gaining access to a flask of in- fusion. It is now well known that if the neck of the flask be drawn out into a long tube and turned downwards, and then a little upwards, even though the end be left open, no contamination will gain access. The force of gravity will prevent them from ascending the long arm of the tube into the neck of the flask and impregnating the infusion. Moreover Major Horrock's bacterium prodigiosus has a very slow and sluggish motion. His conclusion that germs may probably escape from minute droplets ejected from flowing sewage seems perfectly natural and requires no special explanation. A repetition of Major Horrock's experiments by another well known bacteriologist* recorded in the following table showed similar results, and in this case also the germs eject- ed were so few as to be, from a sanitary point of view, con- sidering the great volume of the air into which they were transmitted, entirely negligible, as he showed in various ways and from the following table. BACTERIA IN AIR OVER FOAMING LIQUIDS. B. prodigiosus per liter. Experiment. In liquid. In air. 1 630,000,000 0000 2 680,000,000 0000 3 230,000,000 0100 4 5,000,000,000 0130 5 1 ,000,000,000 0000 6 2,700,000,000 1 o o 1 7 1 ,800,000,000 000 8 4,400,000,000 000 He found that even under conditions of foaming and bub- bling very favorable for ejecting bacteria into the air from *See report of Prof. C. E. A. Winslow's experiments for the National Association of Master Plumbers. 121 Plumbing and Household Sanitation. liquids containing many millions and even billions of bac- teria per liter,* the number so ejected was so very small as to be practically negligible. Most accurate methods of detection were employed, so that there should be no question of detec- tion of any germ released from the liquids swarming with them. Prof. Newman** gives a provisional list of normal sewage bacteria as follow r s : (i) Coli com- munis, (2) proteus vulgaris, (3) B. enteriditis sporogenes, (4) liquefying bacteria, B. subtilis and B. mesentericus, (5) non-liquefying bacteria, (6) sarcinae, yeasts and moulds. No pathogenic bacteria are included in this inventory. "Doubt- less," he says, "such species (e. g., typhoid) not infrequently find their way into sewage. But they are not normal hab- itants, and though they struggle for survival, the keenness of the competition among the dense crowds of saprophytes makes existence almost impossible for them. * * * There is no relationship between the microbes contained in sewer air and those contained in sewage. Indeed, there is a marked difference which forms a contrast as striking as it is at first sight unexpected. The organisms isolated from sewer air are those commonly present in the open air. Micro- cocci and moulds predominate, whereas in sewage bacilli are most numerous. * * * Pathogenic organisms and those nearly allied to them are found in sewage, but absent in sewer air. * * * Lastly, only when there is splashing in the sewage, or when bubbles are bursting (Frankland) is it possible for sewage to part with its contained bacteria to the air of sewers. * * * The interior of the cavity of the mouth and external respiratory tracts is a moist perimeter from the walls of which no organisms can rise except under molecular disturbance. The position is pre- cisely analogous to the germ-free sewer air as established •About a quart. •♦Demonstrator of Bacteriology in King's College, London. In his work entitled "Bacteria," published by John Murray, London, 1899. 122 Micro-Organisms in Sewer Air. by Messrs. Laws and Andrewes for the London City Coun- cil. The popular idea that infection can be 'given off by the breath' is contrary to the laws of organismal pollution of air. The required conditions are not fulfilled, and such breath infection must be of extremely rare occurrence. The air can only be infective when filled with organisms arising from dried surfaces. The other series of investigations were conducted by Drs. Hewlett and St. Clair Thomson, and dealt with the fate of micro-organisms in inspired air and micro-organisms in the healthy nose. They estimated that from 1,500 to 14,000 bacteria were inspired every hour. Yet, as we have pointed out, expired air contains practically none at all. * * * From the two series of experiments which we have now considered we may gather the follow- ing facts : (a) That air may contain great numbers of bacteria which may be readily inspired. (b) That in health those inspired do not pass beyond the moist surface of the nasal and buccal cavities. (c) That here there are various influences of a bactericidal nature at work in defense of the individual. (d) That expired air contains, as a rule, no bacteria what- ever. * * * "It should be noted that the bacilli of diphtheria are capable of lengthened survival outside the body, and are readily disseminated by very feeble air currents." Miquel found during a six years' investigation of the air of Paris an average of 4,000 bacteria per cubic meter in that of Montsouris Park. Fliigge, taking an average of the middle of the city, but only about a tenth as many in too bacteria per meter, estimates that "a man during a life- time of seventy years inspires about 25,000,000 bacteria, the same number contained in a quarter of a liter of fresh milk." The number of bacteria in the air diminishes in cities rap- 123 Plumbing and Household Sanitation. idly in proportion to the altitude, Miquel rinding 750 per cubic meter in the Rue de Rivoli, but only 28 at the summit of the Pantheon. Whereas at the seashore there might average a hundred per meter, the number diminishes as the distance seaward increases, and the maximum distance sea- ward, according to Dr. Fischer's experiments, to which germs can be transported lies between 70 and 120 miles, beyond which they are almost invariably absent. "Of par- ticular interest in these experiments/' says Frankland, "is the very distinct manner in which they show that the micro- organisms which are present in sea-water are not commu- nicated to the air, excepting in the closest proximity to the surface, even when the ocean is much disturbed." All these facts co-operate to show that wet surfaces do not give up their germs to the air under normal conditions. 124 CHAPTER VII. The Disconnecting Trap and the Reasons Why Its Use Should Be Prohibited by Law. HE fact that the air of sewers is freer from all forms of micro-organisms than is the outer air above them ac- counts for the immunity with which pec pie may work in well ventilated sewers, and explains the reason why the great ^ Paris sewers, for instance, are so safe, visited every year by thousands of travel- ers from all parts of the world, with no case on record of resulting disease. It has been related that the most re- markably located hotel in the world was built in these Paris sewers almost immediately beneath the Madeline church to accommodate the municipal scavengers. The interior was described as being singularly neat and clean, and as serving between sixty and seventy breakfasts and dinners to the workmen therein, and these sewer laborers are as healthy as are any other class of laborers in the city. In view of all the facts, it becomes evident that the dis- connecting trap and its vent are really worse than unneces- sary. They are a positive injury as obstructing ventilation and waste discharge, as complicating the plumbing, as forc- ing odors generated in poorly ventilated sewers directly into the crowded streets, sometimes greatly to the annoyance of the people, and, above all, of depriving us of one of the most effective means now known of filtering the air of cities and towns of dust and disease germs. Their use 125 Plumbing and Household Sanitation. should therefore be prohibited by law so that every soil pipe may serve as an effective means of ventilating the sewers and reducing the number of floating impurities in the outer air. This latter advantage I have not as yet seen advanced, though it is of the utmost importance, especially in times of epidemics. So important is this matter and yet so little is it under- stood by the public that we ought to call a little further at- tention to some of the more recent investigations which have been made into the number and kind of bacteria found in the air of the streets and as to their fate when they find access into the sewers through the ventilating inlets. Analyses of the air in the Paris sewers have been regu- larly made at stated intervals and it is found that this air contains on the average more carbonic acid and ammoniacal nitrogen than the street air, but only half as many germs of any kind, while most of the investigators have failed to find any disease germs at all there. In these investigations it has been found also that the humidity in the sewers is great and practically constant. In the air of the sewers of Berlin Petri found that there were only a very small number of micro-organisms as com- pared with that of the streets. Similar results were obtained by other investigators in the sewers of London, Dundee, Westminster, Bristol and Sydney in Great Britain, where classifications of the various kinds of bacteria were made. In all these researches it was found that sewer air is, as far as germs are concerned, very much purer than outside air, and that these germs came not from the sewer but from the outer air ; that a decrease in the number of germs in the outer air was followed by their decrease in the sewer air ; that the kind of germs in the sewer air was the same as that in the outer air, but differ- ent from those contained in the sewage itself. Laws and Andrewes, who were commissioned by the county council 126 Disconnecting Trap Should be Prohibited by Law, to study the bacteria in the London sewers, state that the number of micro-organisms existing in sewer air appears to be entirely dependent upon the number existing in the outer air at the same time and in the same vicinity. They say that if the organisms existing in sewer air were derived from those existing in sewage, then the flora of sewer air should bear a very close resemblance to the flora of the sewage, but that they in reality bear no resemblance what- ever to one another. They say, indeed, "we may go even further and state that, as far as we are aware, not a single colony of any of those species which we have found pre- dominant in sewage has been isolated from sewer air. We consider, therefore, that the study of the sewage bacteria on which we have been engaged fully confirms the conclu- sions previously arrived at from the study of the micro- organisms of sewer air, viz., that there is no relationship between the organisms of sewer air and sewage." * * * "In the conclusions to Part I of this report we endeav- ored to show that sewer air has no power of taking up bacteria from the sewage with which it is in contact . A strong argument in favor of this view is the fact that the very organisms which are most abundant in sewage are precisely those which are absent from sewer air. In the course of previous experiments on sewer air, the nature of the organisms in some 1,200 liters of sewer air was care- fully determined. Not once was the bacillus coli communis or any of the predominant organisms of sewage found, though we have shown above that the former is present in sewage in numbers varying from 20,000 to 200,000 per cubic centimeter. If this be so, how infinitely improbable becomes the existence of the typhoid bacillus in the air of our sewers. That sewage* is a common medium for the dissemination ♦This is before the disease germs are destroyed in the sewers by coming in contact wtih th^ other bacteria which find in sewage their natural element and which are non-pathogenic 127 Plumbing and Household Sanitation. of typhoid is certain; that sewage-polluted soil may give up germs to subsoil air is possible ; but that the air of sewers themselves should play any part in the conveyance of ty- phoid fever appears to us, as the results of our investiga- tions, in the highest degree unlikely." Now the house drains and soil pipes, being much smaller and longer in proportion to their sectional area, and being more uniformly moistened on their inner surfaces when in use, and having more bends and angles in proportion to their length than the public sewers, are correspondingly more effective in removing any bacteria which may enter them from the sewers. Hence the air of the house drains will, as is quite evident, and as I shall endeavor to make visible by experiments, be found to be still freer from germs than even that of the sewers themselves. As has already been pointed out, the danger from the inspiration of sewer air is generally believed to lie in pre- disposing the system to harm from disease germs coming from other sources. This predisposition is probably due to the gases given out by putrid fermentation, such as carbonic acid, ammonia, sulphurated hydrogen, hydro car- bons and volatile fatty acids, and the danger is in propor- tion to the concentration of these poisonous matters. This danger may be reduced to a minimum or altogether re- moved by thorough ventilation. In order to provide a sim- ple ocular demonstration of the manner in which sewage and the moist surfaces of sewers arrest these fine particles when they are brought in contact with them, gradually clearing the air of them entirely, I constructed several ex- perimental drain pipes of metal and glass tubing and of different lengths, varying from ten to twenty-five feet, some being straight and others bent. These pipes were thoroughly moistened on the inside 128 Disconnecting Trap Should be Prohibited by Law, with water, and a specified quantity of dry fine dust was placed at one end of each, and the attempt was made to blow the dust through the pipes from end to end by means of bellows. Before describing our experiments it is im- portant to point out the relation which dust bears to disease and how it serves to disseminate bacteria through the air. Mrs. Frankland* says in her most valuable work, entitled "Bacteria in Daily Life," published in 1903 : "That it is no exaggeration to describe streets from the bacterial point of view as slums is to be gathered from the fact that much less than a thimbleful of that dust which is associated with the blustering days of March and the scorching pavements of summer may contain from nine hundred to one hundred and sixty millions of bacteria. But investigators have not been content to merely quantitatively examine street dust ; in addition to estimating the numerical strength of these dust battalions, the individual characteristics of their units have been exhaustively studied, and the capacity for work, beneficent or otherwise, possessed by them has been care- fully recorded. The qualitative discrimination of the bac- teria present in dust has resulted in the discovery of, among other disease germs, the consumption bacillus, the lockjaw or tetanus bacilli, bacteria associated with diphtheria, ty- phoid fever, pulmonary affections and various septic proc- ess. Such is the appetizing menu which dust furnishes for our delectation. There can be no doubt, therefore, that dust forms a very important distributing agent for micro- organisms, dust particles, aided by the wind, being to bac- teria what the modern motor-car, with its benzine or elec- tric current, is to the ambitious itinerant of the present day. Attached to dust, bacteria get transmitted with the *Mrs. Percy Frankland, Fellow of the Royal Microscopical Soci- ety, Honorary Member of Bedford College, University of London, and joint author with Professor Frankland of "Micro-Organisms in Water," "The Life of Pasteur," etc. 129 Plumbing and Household Sanitation. greatest facility from place to place, and hence the signifi- cance of their presence in dust." It is also now believed that typhoid fever may be spread by dust, the germs having been discovered in it. A typhoid fever epidemic at Athens a few years ago was believed on good evidence to have been spread by the wind on typhoid dust particles, and epidemics of typhoid in other places have recently been traced to the same cause, the dejecta of suf- ferers from the disease having been thrown in places where it became dried and afterward distributed by the wind. "That the bacillus of consumption," says Frankland, "should have been very frequently found in dust by dif- ferent investigators is hardly surprising when it is realized that the sputum of phthisical persons may contain the tubercle germ in large numbers, and that until recently no efforts have been made in this country to suppress that highly objectionable and most reprehensible practice of in- discriminate expectoration. Considering that the certified deaths from phthisis in 1901 in England and Wales only reached the enormous total of 42,408, and bearing in mind the hardy character of the bacillus tuberculosis when pres- ent in sputum, it having been found alive in the latter even when kept in a dry condition after ten months, it is not too much to demand that vigorous measures should be taken by the legislature to cope with what is now regarded as one of the most fruitful means of spreading consumption." Boards of health and high authorities both here and abroad have stated that tuberculous sputum is the main agent for the conveyance of the virus of tuberculosis in the air- from man to man, and that indiscriminate expectoration should therefore be suppressed. Dr. E. Concornotti has recently made a very elaborate study of the distribution of disease germs in air, with the result that out of forty-six experiments in which the ch? r - 130 Disease Germs in Air. acter of the bacteria found was tested by inoculation into animals, thirty-two yielded organisms which were patho- genic. Messrs. Valenti and Terrari-Lelli found similar results in their systematic study of the bacterial contents of the air in the city of Modena. In their report they state that the narrower and more crowded the streets the greater was the number of bacteria present in the air, and the more frequently did they meet with varieties associated with septic disease. Schaffer has shown that leprosy bacilli may be dissemi- nated in immense numbers by the coughing of leprosy pa- tients, while it has been estimated that 'a tuberculous in- valid may discharge a billion tubercle bacilli in the space of twenty-four hours, and the dried sputum of consumptive persons has actually engendered tuberculous symptoms in the lungs of animals which were made to inhale it. In as many as 71 per cent of bovine tuberculosis cases the respira- tory organs were the seat of the disease. A case is men- tioned by the well known veterinary authority, M. Nocard, of a whole stall of animals becoming infected through the workman attending them being consumptive. He slept in a loft over the cows, and his tuberculous sputum in the form of dust was conveyed to the stalls beneath and so spread the infection. The disease is known to have been spread, on the other hand, from animals to men in the same way.* It has been found by analysis of air containing large num- bers of bacteria that showers greatly reduce their numbers, as it reduces the amount of dust in the air, and that pro- longed rains may clear the air of dust and bacteria entirely. This accords with the action of theVater and wet surfaces of sewers in filtering the air of germs, and if the sewers and house drains are long and wet enough in proportion to •Frankland's "Bacteria in Daily Life. 131 Plumbing and Household Sanitation. the amount of air passing through them, all dust and germs may be filtered from this air entirely. Laws says "It is really remarkable to find that no or- ganisms are given off from the walls of a sewer which has been empty and open to the air at both ends for such a lengthened period as twelve days. The sewage with which the sewer had been kept full for several periods of twenty- four hours would contain no less than three to four million organisms per cubic centimeter, and immense numbers of these must of necessity have been clinging to the walls of the sewer. * * * The velocity of the air current used in the above experiments was five feet and fifteen feet per second, respectively, the latter being far in excess of any current that would normally obtain in a sewer." "Various experiments," says Roechling, "have been made with a view to ascertain how far germs can be carried away by air currents in pipes and sewers. Hesse, who first investi- gated this point, took a 2-inch glass tube about one yard long, the inside of which he had covered with a layer of nutritive gelatine, and sucked air through it at a slow rate. When examining the tube afterwards he found that a large num- ber of bacteria had settled in its first fourth, that the number was somewhat less in the second fourth, and that it still further decreased in the third fourth, and that no bacteria at all had settled in the last fourth." Ficker remarks that in his experiments in the Hygienic Institute at Breslau a current of air, with the velocity of several meters per second, was not able to lift up specific germs from half-moist soil, and that a current of the same strength was not capable of carrying away germs which had dried on several substances and adhered to them. Author's Experiments and Suggestions for Improving the Air of Cities. Various kinds of dust, from fine lint up to fine and coarse 132 Disease Germs in Air. sawdust, were used successively in my own experiments. Dry powdered substances of different kinds, such as whiting cement and fine flour, were also used. Bacteria, being tine particles of organic matter, resemble these fine dusts in the manner in which they may be wafted about on air currents and are retained by water. In no case could any of the particles which came in con- tact with the wet sides of the pipes be seen to be blown off again. If any escaped they were too few and small to be detected. The bellows were large and strong, capable of producing at will either a powerful draught through the pipes or a faint and almost imperceptible current. With the short pipes it was possible to drive some of the particles through in a strong draught because these did not have time to come at all in contact with the moistened surfaces, but with pipes twenty-five feet long and one and a half inch in inside diameter none could be forced through even under a pressure strong enough to put out the flame of a candle at the further end. Where bends were introduced the same result was obtained with shorter pipes. Fig. 51. With gentler pressures still shorter pipes sufficed to en- tirely filter the air of all particles, however dry and finely powdered ; and, in the very slowly moving air currents found in the average sewer, a very short travel is sufficient to arrest all dust or bacteria of every kind. The same experiments were then tried with the pipes thoroughly dried on their inner surfaces. In these cases all of the dust was easily blown through all the pipes after a more or less prolonged application of the air pressure, the surfaces of bends arresting for some time some of the par- ticles by back eddies, but all eventually passed through. With jointed pipes, however, as might be expected, some little of the dust and powder would be permanently retained in the fine cracks of the joints. 133 Plumbing and Household Sanitation. The interiors of the pipes were next coated with sewage and moistened, and the experiments were repeated under these conditions with the same results obtained in the first experiments with pipes, moistened with water alone. No particles once coming in contact witn the moist surfaces could ever be detached again, however strong the air cur- rent, so far as could be observed. Only the particles of dust which happened to travel from end to end in the middle of the air blast escaped from the pipes, and, as before said, this only occurred with short pipes and in currents stronger than those which prevail in ordinary sewers. As has been said, it is generally conceded that bacteria may rise through water in the center of bub- bles bursting 6n the surface, or in droplets caused by agita- tion or spraying. But in well ventilated and properly con- structed sewers such splashing and bubbling may be largely avoided. But should they occur, the very few bacteria thereby escaping into the air of the sewer could only travel a short distance, as we have shown, before they would again be caught and, if of the pathogenic kind, be quickly de- stroyed. Finally, the pipes containing the particles of dust of vari- ous kinds imprisoned in the moisture and organic refuse along their inner surfaces were thoroughly dried by ex- posure for several days to the dry air of the laboratory, and then the air blasts were repeated to see whether the dried particles of matter caked against the walls of the pipes would give up the dust and bacteria blown against them when they were wet. None of the dust escaped, so far as could be seen. Under the most powerful blasts pieces of caked refuse would occasionally be torn off the surfaces to which they would normally adhere, but these were heavy and fell directly to the ground as soon as they were blown from the pipes. The dust particles still remained firmly 134 Experiments on Passage of Dust-Borne Bacteria. imprisoned in these masses of scale and were therefore as powerless to do injury as if they had never been detached from the part of the pipe against which they originally fell. The masses containing the separate particles of dust or bac- teria were simply transferred from one part of the pipe system to another. The reason for this is obvious. Wet sewage, containing many kinds of glutinous and fatty mat- ters, forms, when it dries, a more or less pasty mass, which hardens into a tenacious cake, and in these experiments appeared to hold the dust or bacteria enmeshed in its mass as firmly as it did when it was in its moist state. Thus we see that the sewers really form vast filters, as it were, for clearing the air which passes through them of germs of disease, and it is the province of the science of sanitary engineering to make the most of this wonderful .provision of nature in man's behalf by co-operating with her methods and increasing to the utmost extent the ven- tilation of the sewers and drains. We know, for instance, that, especially in times of epi- demics, the air of the streets contains many disease germs. If we could erect in front of our windows and doors con- tinuously moistened filters of such a construction that no particle of air could enter the house without first coming in direct contact with some part of the moist surface of the filter, and if the filter could be provided with a germicide maintained constantly active, it is certain not only that the inmates of these houses would be shielded from the diseases conveyed by germs as long as they remained within the protection of the filters, but also that the germs themselves in the locality would gradually be diminished in numbers until, if the traps were numerous enough, all might ulti- mately be destroyed. Now the sewers form precisely such filters, and if copi- ously ventilated by pure air currents induced by making 135 Plumbing and Household Sanitation. every house drain a suction pipe, no offensive odor could come from the sewers, and all the air thus drawn in from the streets would be freed from dust and germs. How short-sighted and foolish it is, then, to legislate against such beneficent ventilation and purification by re- quiring a barrier to be interposed at every house drain out- let, by which the only really practicable way of thoroughly ventilating the sewers is prevented. There is no way known of setting up such screens as I have described in front of our windows. But it is easily possible to utilize the sewers already provided for us and equipped with a most marvelously effective dust arrester and germicide. I do not say that with such perfectly constructed and ventilated sewers as these it would be wise in times of epi- demics to nail up our windows and ventilate from the sewers, because the house drains and soil pipes will always contain foul gases, which it will justify the use of our best science to exclude from the house, and because the smallest of the city sewers would have to be enlarged for such service to the size of a Hoosac tunnel. But I do say that any air which might accidentally enter the house through them would be safer to breathe, so far as disease germs are con- cerned, than that which would enter through the windows, and that no odor would enter the house from the sewers themselves, however much might be generated in the pri- vate drains, because the warmth of the sewage and of the house would always create an upward draught in cold weather and fresh air would enter the sewers through the street openings everywhere provided for it. In hot weather citizens could take their choice between disease germs from the windows and an occasional odor from the private drain. Supposing, now, that the houses of an average city aver- age twenty-five feet in width on the street lines, if we were 136 Author's Suggestion for Filtering the Air of Cities. to ventilate the sewers through every house drain we should have suction openings every twelve and one-half feet into the sewers, and these drains being four inches in diameter, we should have about twelve and one-half square inches of suction area for every twelve and one-half feet of sewer, or one square inch for every foot of sewer in a city. For supplying the air to the sewers corresponding street open- ings would be provided. If we assume an average of twenty-five miles of streets in every square mile of a city we have for a city containing ioo miles of street about 528,000 square inches or 3,666 square feet area of sewer ventilation, which would be equiv- alent to a round ventilating flue sixty-eight feet in diameter or to 130 round flues six feet in diameter each. Supposing the average height of the houses in our city to be fifty feet, and that the quantity of air discharged per minute through the 4-inch ducts of the 42,240 houses in our city of a mile square be estimated. Assuming that these ducts draw up the air at the rate of 419 feet per min- ute per square foot of ventilating area for an average dif- ference of temperature in winter between the air of the house and that of the street of 30 F. (calculated under the (>-') formula V=240^f ^— — — in which V stands for the ^ 491.4 velocity of the current, h the height of the building, t t the interior and t the exterior temperature, and allowing 50 per cent for loss by friction), we have a ventilation pro- duced by all the 42,240 ducts of 1,536,054 cubic feet of air per minute. Allowing five occupants for each house, we have some- what over 200,000 inhabitants in our city of a mile square and our sewer ventilation would thus filter the air at the rate of over seven cubic feet per minute for every inhabit- 137 Plumbing and Household Sanitation, ant, or if we make a much larger allowance for friction and assume a smaller difference of temperature between the inner and outer air, we have a sewer ventilation of say from one to five cubic feet of air per minute for each inhabitant. The warmth of the sewage produced by the introduction of warm water into the drains would under these circumstances always produce suitable ventilation even in the summer months. Thus the sewer ventilation produced by the omission of the main house trap and its vent would not only be the most perfect that can be devised, but it would reduce the Fig- 51. Apparatus for determining the degree of retention of bac teria by the moist surface of sewers and drains. cost of the whole sewerage system by a large percentage, in fact, over half a million dollars in our city of a mile square. In rebuilding the city of San Francisco probably several millions could be saved in this manner. Fig. 51 shows our glass and metal sewer and drain pipe as arranged for the lecture room. The measured pile of dust to be experimented with is shown at the bellows end x>i the pipe. The first opening provided with a stopper is for the introduction of the dust. The other openings are to permit of tests being made upon short or long pipes and upon straight or bent pipes, as desired. The arrows indicate the direction of the air currents 138 Author's Suggestion for Filtering the Air of Cities. and the manner in which the dust particles are blown against the moist inner surfaces of the pipes to which they adhere. The bend in the middle of the pipe may be placed either horizontally or vertically. When vertical it becomes a trap and arrests, when full of water, all dust and germs. 139 CHAPTER VIII. Sewers. Figures 52 and 53 represent sections of large Paris sewers. They carry both the house drain- age of all kinds and the street washings and rain or storm water. They come under the "combined" system of sewerage as distinguished from the "sepa- rate" system in which rain water is separated from the house wastes. The egg-shaped sewer (Fig. 50, initial cut) is the usual form now employed. Where a flat invert is used, as in Fig. 50, greater convenience is obtained for cleaning the flat portion, giving better foothold for the men. But for the conveyance of small quantities of sew- age the regular tgg form is better. The section, Fig. 53, shows a form of sewer in which the gas pipes are submerged in a channel on one side filled with water to prevent leakage of gas. The advantage of the separate system is that the flow is uniform and the dilution of the sewage is at its minimum, in which condition the valuable manurial part can be sepa- rated and the water purified and emptied into rivers or the ocean at a minimum of expense. In places where the grades are such that the rain water can be carried off in surface Fig. 52. Section of Paris sewers. 140 Sewers. gutters to the ocean or river courses, the expense of the separate system is obviously much less than would be the combined. But where a double system of sewers would be required, as, for instance, in Paris, the cost would be greatly increased. The section in Fig. 55 shows a method by which the separate system might be used in a single sewer pipe, the drain water being shown in its maximum flow in the larger conduit and the house sewage in the smaller. By carrying the rain water pipes from the street gutters over Fig:. 53. Section Paris sewers. Fig. 50. Section of Egg-Shaped Sewer. the house drainage conduit the position of their outlets might be so adjusted with reference to the latter that the first washings of the street would fall into it, and the storm water, as the storm increased in volume, would afterwards leap over it and fall into the larger conduit. Whatever system be adopted, the sewer should be venti- lated sufficiently often to render the air in the sewer per- fectly pure, and such ample light should be provided as to give the double advantage of convenience of inspection and the freedom from the undesirable anaerobic germs to which strong light is inimical. Frankland shows in a plate we have reproduced in Fig. 56 in a very interesting manner, the effect of sunlight on 141 Plumbing and Household Sanitation. disease germs. He placed the letters spelling the name of the particular disease germ upon which he experimented, cut out of opaque paper, upon a plate of gelatine inoculated with the germ, and exposed the plate to diffused sunlight. The germs protected by the paper letters multiplied rapidly, while all those in the unprotected parts of the plate were Fig. 55. Writer's method of combining both conduits of the separate system of sewerage in a single sewer. destroyed, so that when the paper had been removed the disease germs had written their own autograph, as shown in the picture. Ample lighting as well as ample ventilation is a sanitary measure everywhere. 142 Sewers. The inner surfaces of all sewers should be lined with glazed materials; and in large sewers with white glazed or enameled tiles to increase the light reflection and insure greater cleanliness. Now that draught animals in our streets are gradually being supplanted by machine motors, the streets will soon be paved with smooth materials and be kept perfectly clean. Autograph of cholera germs. This will tend to greatly simplify sewerage and effect a much more general adoption of the separate system en- abling us to come much nearer the ideal of waste water purification and recovery of its useful manurial part, at a minimum of outlay. Figs. 57 and 58 show old Paris sewers, the illustrations 143 Plumbing and Household Sanitation. being taken from Victor Hugo's "Les Miserables." These sewers carried the storm waters and house drainage with the exception of part of the W. C. refuse which was at that time almost exclusively collected in cesspools. Today the cesspools are gradually being removed and everything will soon be conducted directly into the sewers. The waste from the street urinals and the liquid overflow from the house cesspools was, however, taken into the sewers long before the crusade against cesspools was undertaken. Nevertheless the sewage today contains probably far more water in pro- portion to the bacteria within than it did at the time of Jean Valjean, because the supply of water to the closets fully offsets any additional impurity they furnished. Moreover, sink water and urine form the most dangerous parts of the house water. But the unscientific manner in which these old sewers were constructed and operated made them little better than elongated cesspools, as compared with the mag- nificent and cleanly conduits they appear today. In 1882 Paris still had 80,000 cesspools and 30,000 shal- low drinking water wells, most of which were contaminated and entirely unfit for use. These pictures show the appearance of the old Paris sewers in 1805, when Bruneseau visited them with a view to their improvement. Fig. 57 presents the engineer making what Victor Hugo calls "the formidable campaign" — the "nocturnal battle against asphyxia and plague." Eight out of the twenty workmen gave up the battle in the middle of it. The ladders for measuring would sink three feet deep in mud, and the lanterns would scarcely burn in the mephitic atmosphere, the men fainting from time to time. There were horrible pits in the ground in which one man suddenly disappeared. The walls were hanging with fungi. Among other things they found the skeleton of an ourang-outang, which had disappeared from the Jardin des Plants in 1800 144 Sewers. Fig. 57. Bruneseau visiting the old Paris sewers. 145 Plumbing and Household Sanitation. Fig. 58. Junction of old Paris sewers. Miserables." From Hugo's "1-es 146 Sewers. and drowned itself in the sewer. They found, also, on the other hand, valuable objects, coins, gold and silver, jewelry and precious stones. Fig. 58 gives the point of junction of several of these old sewers, described by Hugo as "winding, cracked, un- paved, full of pits, broken by strange elbows, ascending and descending illogically, fetid, savage, ferocious, submerged in darkness, with gashes on its stones and scars on its walls." The various methods of sewage purification now in opera- tion in various parts of the world have shown the water carriage system of disposal to be far in advance of any dry system. Erwin F. Smith in his treatise on "The Influence of Sewerage and Water Supply on the Death Rate in Cities," read at the sanitary convention in Michigan, July, 1885,* shows by charts I, II and III the reduction of the death rate of cities occasioned by the introduction of sewerage systems, and in spite of their antiquity they form as pow- erful arguments in favor of good sewerage as can be found. His conclusions are: (1) Typhoid fever and cholera decrease in proportion as a city is well sewered. (2) There is no direct relation between diphtheria and sewers. (3) The general death rate falls after the sewering of a city, and, other things being equal, never again reaches the maximum of its anti-sewered condition. (4) The cost of building and maintaining sanitary works is inconsiderable, in comparison with the direct pecuniary loss, by sickness and death, which their absence entails. ♦Reprinted from Supplement to Annual Report Michigan State Board of Health. 147 1 8 ?^ S So s ^ 1 5 It (o ^ a « _£3 7?**' 1 1 H ^!i, ■ *ttfo Cv c -o46/ « 1 'i'oYv 1 ¥}'°> r— 2 -VfrSf S-, 1 SB, -019/ ■a 698/ -094/ iS-8/ So 1 r es4t -9 At/ -Tit/ — ; 1 V£4/ -0S4/ (TV .'0 ' - /88 1 SI -0191 9* 068/ -oj SI 1 a C 9 -J '+8 4 /„ 9 9 8 J \<-> 1 S Z 3 i >s 1 4 38 f 3 u w», ■■■SI 1 Hii, J •419/ ~S?S/ _ C c tiSi, ■ii ' 6 -m, TO * 1 £18 / -9J8l ■ u '/r 88 / -Si it 1 °~? 1 '618/ -CIS, T6S 1 - *S8 1 CS a Hilt ■■■■I 1 «Vi/ <>■ 9t*/ - /s a/ af. y <£ 'fiii' -in/ i OSS/ -9£Si l-s* ■■<■ I t / - C? 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STOTST* ■itesf 0- s ^^J^^J I 1 -^~ *'3v^S)in»5 "M - U fl t K Kf ■ — *S -04 'A -=- 3j a-9/ J/J «.»/<« a •«7 0/ >^ »*/ A< - /i -M <; CO u '<><*».>; YO o - ■■ ■ I P CO " M a -=- 'VM^W ■■»!■ ■MilHHIBIHiaHiaiHBII ' *V i/j;/| r^ ■ 1 •^o/yuwj -c : HI 1 . i^ * nv t S: "fl ►J Q 2 0J ■$.' S^aijnjg g "— < """l«07 SI ■OOQ'0/«X*W»3(l r^ ^> !*S J- <^> cs> 5 Or- ao r- «sS !*> *■ **ij svj^ J 150a Approximate Estimate of the Comparative Average Cost of Plumbing Work Under the Present Complicated and the New Simple System Complicated System Simple System Simple in Alter- System ations In considering the various items of compar- ative cost of plumbing under the old and new systems we may classify the chief items of simplification as follows: — (1) The back venting of traps should be prohibited. In estimating the saving which would come from this item we find that no close fig- ure can be given without making a very exten- sive study cf the different conditions involved, aided by exhaustive statistics. Very high build- ings would require, for effective back venting, such an increase of size of pipe for each ad- ditional story to overcome friction, that the cost of the back vent pipes would far exceed that of the waste pipes. In buildings of the average height the cost should about equal that of the waste pipes. We may take Figs. 264 and 265 for fair examples of the two meth- ods of piping for such buildings, except that in Fig. 264 the back vent pipes have not been sufficientlv enlarged in the upper stories. (See Chap. XLIV.) (2) Flexible joints and "Standard" thick- ness of pipes should be substituted for "lead caulked and rigid joints with "Extra heavy" thickness. "Standard" thick cast-iron pipes weigh about half as much as "Extra heavy," and the cost of the former, considering the comparativelv high cost of hand caulking is less than half that of- the latter. See Note on pages 694 and 695. (3) The use of the main house trap and its foot vents and other piping involved should be prohibited. The percentage of saving in this item depends upon the amount, of piping which would be con- sidered by different persons as necessitated by the use of this dis- connecting trap. It would sometimes amount to a very large sum. (4) The law calling for separate traps under each of several connecting fixtures should be modified. This would also sometimes amount to quite a . large percentage, especially where back venting is difficult. (5) The law requiring water closet rooms to be ventilated by spe- cial air shafts lighted by external windows should be modified to per- mit of their ventilation through effective ventilating pipes or ducts. This requirement sometimes involves the loss of exceedingly valua- ble room and outer wall space without any advantage, as explained in detail on pages 595 to 598, and the average saving possible in this item runs up to a very high figure. (6) The law forbidding soil pipes to serve also as rain water conductors should be changed where the combined system of sew- erage is used. This would there save one or more stacks of large pipes from roof to basement. (7) The use of the hydraulic test for piping should be prohib- ited, because, while very expensive and altogether useless, it puts a strain on the piping far beyond what could ever be encountered in practice, and which, like excessive boiler pressure tests, for instance, may result either in destroying the property at once, or in develop- ing unseen defects liable to appear disastrously in the future. Taking all these large items together, and several smaller ones not here mentioned, the author believes the relative costs of the two systems of plumbing may be fairly represented by the compara- tive sizes of the squares shown in our initial cut. (See Chap. XLIV.) 150 b CHAPTER IX. Fie 62. Old English D Trap, styled the "Goose" Trap, prob- ably in honor or the man who invented it Traps. \ trap is a siphon placed in the dram to catch some of 'the water discharged from a fixture and form with it a barrier for the .entrance of air from the drains into the house. The water forms what is called the trap "seal." In addition to the water seal some form ot mechanical closure has sometimes been added in the form of a valve, gate or ball ^ the suDDOSition that a water seal alone could not afford surhcient seal becomes entirely superfluous. The four principal enemies of the water seals of traps are^iphonage (which is the suction acting on trap seals ^Tced by a partial vacuum in the waste pipe behmd a falling plug of water discharged from a fixture), evap oration back pressure and clogging by sediment accu- "Sn ThL enemies of trap seals will be examined in full detail in subsequent chapters. Under the supposition that all traps are liable to lose Under tne -W 4 honage momentum and back the,r " or Sw of thttraSmisfion of gas bubbles under rcr^^urfuIlefsVotected by special ventilation, the 151 Plumbing and Household Sanitation. "back vent" law was passed requiring a separate vent pipe to be carried from the outgo of every trap into a special ventilation duct, independent of the soil pipe ventilator, up as far as to a point above its connection with the highest fixture. At the time when this provision was framed no simple and reliable self-cleansing water trap was known which could resist the severest tests of siphonage, momen- tum and back pressure which might be encountered in plumbing. Had such a trap been known, as is now the case, the back vent law would obviously never have been made. The common round or "pot" trap, though not self-cleans- ing, can nevertheless be made large enough to be practically proof against siphonage, and it may be periodically cleaned by hand if it is found to clog with sediment ; but no trap, and least of all the S trap, can resist the destructive effect on its seal of the rapid evaporation produced by the ven- tilating current required by this law. The seal is destroyed by evaporation in a very short time, varying with the rapid- ity and dryness of the current and the volume of water in the trap. Special trap venting is now considered undesirable for many other reasons which give rise to dangers much greater than that which it pretends to remove, the danger from evaporation, for instance, being, as houses are now plumbed, much greater than that from siphonage. Traps are left in disuse, and subject to the danger of loss of seal by evapora- tion much oftener than is generally supposed. Thus they are unused in city houses which are left unoccupied during summer; in country houses which are unoccupied during winter ; in hotels and apartment houses during the quiet seasons, or at times when they are only partly filled ; in private houses in the spare chambers reserved for visitors ; in business offices between the expiration and renewal of 152 Traps. their leases ; in schoolhouses and all public and private office buildings at times of vacation ; in houses or chambers closed on account of the absence of their owners for travel, sick- ness, death or any other cause ; in case of drought, or "cut- off" of water supply for repairs of pipes, rebuilding or other cause ; in extra fixtures in houses, and in other places, and at other times which will, upon reflection, occur to the reader. In a few days after a trap has thus been abandoned to the influence of the ventilating current, the time varying with the dryness and velocity of the current and with the volume and amount of exposed surface in the body of the trap, its seal will be destroyed by evaporation. Corrosion of well-flushed waste pipes of moderate length by sewer air is never to be feared with ventilated soil pipes. It is believed that there is no authenticated case on record of such corrosion. Indeed, the induction through the branch pipes of soil pipe air is by no means an advantage when ample pure air from the room is available after every flushing from a properly constructed fixture. When the main soil pipe is properly ventilated the diffusion of gases, the absorptive power of water for gases, and the frequent water flow through branch pipes afford them sufficient pro- tection when the pipes are in use. When the pipes are not in use the waste matters adhering to their inner surfaces dry up, and it is believed that what decomposition then takes place goes on so slowly that its corrosive effect on the pipe is practically inappreciable. We have shown that besides the constant draught on the water seal by evaporation, the vent pipe increases the unscoured area of the trap, and if any portion of a trap not directly scoured by water passing through it is liable to collect sediment, and ultimately clog up, then the mouth of the vent pipe is also subject to this danger. It thus, in a measure, defeats one of its own ob- jects — i. e., to provide a safe trap which shall be self-cleans- 153 Plumbing and Household Sanitation. ing and contain no chamber or corner which shall not re- ceive the full scour of the water passing through this trap. Now, the ventilating openings of traps having been so often found clogged and even completely closed by sediment, we see that this precaution is no certain protection against siphonage and momentum. CLASSIFICATION OF REQUIREMENTS OF TRAPS. A proper trap should possess the following character- istics : (i) It should do its work by means of a water seal alone. (2) It should be self-scouring. (3) It should be capable of resisting the severest strains of siphonage, momentum and back pressure that can ever possibly be brought to bear upon it in properly constructed plumbing, even when this plumbing is unscientifically used by the occupants, and this without the aid of special trap ventilation. (4) It should contain a body of water large enough to be practically proof against evaporation. (5) It should be simple, of durable material and econom- ical to manufacture, with smooth porcelain enameled surfaces. (6) It should be so constructed that its interior can be inspected without removing the trap. (7) It should have a tight- fitting, easily accessible clean- out cap, to admit of removing easily any valuable or foreign substance that may have lodged in any part of it. (8) It should ofTer the minimum of resistance to the flow of water through it. (9) It should be ornamental in appearance. (10) Finally, it should be independent of the fixture to which it is attached and should be easily connected or dis- connected. 154 Traps. At first thought it would seem as if some of the above requirements were incompatible or even positively antag- onistic. How can a trap which is perfectly self-scouring and simple be made to resist the most powerful action of siphonage, momentum or back pressure without the aid of some mechanical seal? It is nevertheless possible to obtain this result, and the manner in which it is done will be shown hereafter. CLASSIFICATION OF THE DIFFERENT KINDS OF TRAPS. Traps may be divided into two principal classes : I. Mechanical traps. II. Water seal traps. Each of these may be again subdivided as follows : I. Mechanical traps may be subdivided into: (a) Hinged-valve trap. (b) Gravity-valve trap. (c) Floating-ball trap. (d) Gravity-ball trap. (e) Mercury seal trap. II. Water seal traps may be subdivided into: (a) Sediment traps. (b) Self-cleansing traps. These two classes may again be subdivided as follows : (a) Sediment traps may be subdivided into: (i) Air-vent traps. (2) Reservoir traps. (b) Self-cleansing traps may be subdivided into: (1) Siphonable trap. (2) Anti-siphon trap. Finally self -cleansing anti-siphon traps may again be sub- divided into: (a) Deep seal traps. (b) Shallow seal traps. 155 Plumbing and Household Sanitation. Mechanical Seal Traps. Mechanical closures alone, without the water seal, are of as little use in plumbing traps, in excluding sewer gas, as could be the mechanism shown in Fig. 63, which shows the peculiar form of mechanical trap found under all the sinks of a tenement house whose landlady had received orders from the Board of Health to have "traps put under every plumb- ing fixture." The old &£ lady obeyed the order j^t to the letter, but in do- ing so exposed an igno- rance of household sani- tation so dense that even the rats themselves be- came rudely derisive and hilarious. They carried Pif. 63. Peculiar form of trap r nP i r ridirnle so far as found under the sinks of a tene- uieir riaiCUie SO iar as ment house whose landlady had * n withdraw the rhppse received notice from the Board of lU >\ linaraw tne cneese Health to have traps put under f rorn rnp trans hv means every plumbing fixture. irom me iraps Dy means of skewers in order to demonstrate the futility of mechanical gates in traps. Two investigators climbed up into the sink to ascertain the result of the woman's stupidity and, in still further contempt, sim- ulated instant death, as you see, from the "deadly" sewer gas which emanated from the unprotected waste pipe, while 156 Traps. four others were obliged to hold their sides to prevent them from splitting with their vulgar laughter. These almost incredible facts are recorded to show the as- tonishing amount of ignorance displayed by the public of the functions of traps and plumbing work generally. All our good lady knew about drainage was that she emptied slops into the sink, and that the slops then went "the devil knew where." Mechanical seal traps, like pan, valve and plunger water- closets, have served their purpose, and must now be laid aside in the general march of progress. Before the necessity of ventilating the main soil pipe was felt, and when the science of plumbing was still more un- developed, back pressure in every trap from the sewers was a thing to be guarded against where the sewers were foul, and balls, gates and valves in traps were invented to supply an actual want. Now, however, the universal and most de- sirable custom of ventilating every stack of soil pipes, and a better understanding of the hydraulics and pneumatics of plumbing has done away with this requirement, and the me- chanical seal serves no longer any other purpose than to ob- struct the proper flow of the waste water through the pipe, and to collect sediment, besides causing a false sense of secur- ity in case of evaporation or siphonage of the water seal. It is evident that the mechanical seal is entirely superfluous, since everything a trap is required to do can be done by other better and simpler means. Moreover, we cannot apply me- chanical seals to water-closet traps, and this fact alone shows the uselessness of applying them to smaller traps, since we must rely on the water seal alone in some of the fixtures in all houses. It has been claimed by some makers of ball traps that the rotary movement of the ball in the water scours the sides of the trap and prevents the collection of sediment, just as 157 Plumbing and Household Sanitation. shot when shaken up in a bottle will aid in cleansing it. This is, however, not the fact, as both experience and theory have proved. Ball traps which have for some time remained more than usually clear of sediment owe their cleanliness, not to the movement of the ball, but to the scouring action of the water, which proves, to a certain extent, effective in spite of the ball. The ball breaks, more or less, the force of the water flowing through the trap, and by just so much diminishes its scouring effect. To claim the reverse is an evident absurdity calculated only to mislead, and is easily disproved by practical experiment and by examining ball traps which have been in use for a short time. Many make the mistake of supposing that, because shot or any similar substance will help cleanse a vessel when the vessel is shaken, the mere presence of the bodies in the vessel will do the same under a current of water. This is a mistake. We cannot violently shake up the trap on a fixture as we do a detached bottle, and a current of water powerful enough to shake up the shot or ball without such movement of the ves- sel would easily shake up and remove any other sediment which might pass into the trap. When traps are so connected up with flexible pipes that they can be violently shaken every few days, as our grand- fathers tell us the old-fashioned schoolmaster was accus- tomed to shake up unruly boys for the purpose of remov- ing their cussedness from them, the trap ball may be made to serve the same purpose, and will perhaps be equally ef- fective. Until that time the water flushing will be retarded by every form of obstruction in the trap, whether inten- tional or accidental, and a current of water powerful enough to shake up the ball effectively will easily shake up and remove any other sediment entering the trap, as we have said. Coarse sand, gravel, coffee grounds or similar sharp substances in the waste water will add to its scour- 158 Traps. ing effect in removing grease from the pipes ; but this is due to the momentum acquired in falling with the water from the fixture, and to the sharp, cutting edges of the substances. Thus tea leaves, having no sharp edges, when admitted with the waste water, serve only to clog the pipes. But coffee grounds, though often recommended, are not regularly stored away by the thrifty housekeeper for flush- ing drains. She would prefer a well-formed fixture, con- structed as will hereafter be explained, which will do the work for her more scientifically and reliably. A slimy filth, or a thick, matted coat composed of de- composing organic matter, collects around the ball or valve and their chamber in greater or less quantity, according to the size and strength of the water flow through the trap. Hairs and lint soon collect under and stick to the working parts and prevent their closing tightly, and hinges corrode in the vapor or water until the mechanism refuses to close at all beyond a certain point. Their obstructive power gradually increases until even what little cleansing power the water possessed at the outset may be entirely destroyed. The mechanical seals of traps are valueless as regards siphonage, because this action takes place in the direction in which the mechanical obstructions open. Im- munity from the evil effects of siphonage depends, as will be hereafter shown, entirely upon the form and dimen- sions of the waterway of the trap. It is sometimes claimed by the manufacturers that the presence of a hollow elastic ball in a trap would prevent bursting should the water in the trap freeze. If the ball extended from the top to the bottom of the trap and its sediment chamber, it might protect it from the effects of frost. But this is not the case. Above and below the ball the freezing water is evidently no more affected by the ball than if the trap contained no water except in these 159 Plumbing and Household Sanitation. places. Experience proves this to be the case, for the hollow ball traps burst like other traps when exposed to frost severe enough to freeze suddenly the water beyond the parts occupied by the ball, and to break a glass of the same form and size not containing a ball. In our drawings illustrating various types of traps in use, all the traps have been drawn to substantially the same scale and size of inlet pipe, so that their relative sizes can at once be seen. This will prove very useful in enabling us to judge of their merits, especially as far Fig. 64 as concerns the probable scouring effect of the water cur- rent on their walls. (a) Hinged-Valve Trap. Figs. 64, 64 bis and 65 show three forms of the hinged valve. If the valves in these traps could only be main- tained clean and operative, they would somewhat protect the water seal from evaporation produced by the ventilating current. The swellings in the bodies of these traps very slightly increase their power of resistance to siphonage, but 160 Traps. the enlargement would have to be carried much further be- fore they could be safely used without ventilation, and the retardation of the water passage due to the valve would then increase the rapidity of fouling inevitable with all forms of pot traps. The hinged valve is the worst kind of mechanical closure that can be used in the smaller house traps, the slightest corrosion or sediment at the hinge ren- dering the mechanism inoperative. (b) Gravity Valve Trap. Fig. 66 shows a valve trap invented by Col. Waring, but afterwards frankly condemned by him in his general con- ; * Fig. 67. demnation of all mechanical traps. The valve chamber is, however, reduced to a minimum, and the trap in operation is perhaps as a whole as self-scouring as any mechanical seal trap known. The arrangement of the valve is such as to preserve the water seal of the trap for a considerable time, even under a powerful ventilating current. Siphon- age unseals it, nevertheless, quite easily. This and other mechanical seal traps would be useful on account of their 161 Plumbing and Household Sanitation. power of resisting the back pressure were there no simpler means of accomplishing the same result. Fig. 67 represents a trap which has enjoyed a great pop- ularity. In resistance to siphonage it is equal to a bottle trap of the same size, but has the advantage in this respect over such a bottle trap that when the water seal is broken the ball would still float up against its seal, and form under some circumstances a partial seal of itself. Unfortunately the roughness of the ball surface or of any form of mechan- ical closure would prevent its providing proper protection against the passage of sewer air in such a case. Under the ventilating current produced by back venting this type of trap suffers precisely as much as an ordinary bottle trap holding the same quantity of water, the evap- oration proceeding from the sewer side. The ball affords no protection against evaporation because it is on the house side where the evaporation is so slow as to be practically negligible compared with the sewer side. The amount of water which the ball displaces more than offsets the delay to evaporation caused by its partial closure of the inlet pipe. (d) Gravity Ball Trap. Figs. 68 to 73 represent different forms of gravity ball traps, or traps in which the mechanical seal is formed by a ball resting on the top of a bend in the inlet pipe, and partially closing the passageway by its weighty bulk. The seal, as in all mechanical traps, is dependent upon the ac- curacy of the fit of the valve or ball and its seat. This fit is never absolutely air tight, even when new, as may be seen by emptying a new trap of its water, and, when quite dry, testing it for the passage of air or gas between the mechanical closure and its seat. However smooth and ac- curate their surfaces may appear to the eye, the particles forming them are colossal masses, as will be seen under a microscope, compared with the infinitesimal atoms forming 162 Traps. the elements of air and gas, which defy the highest magni- fying power to render them visible. These surfaces, rough as they are, even when new, as compared with the sub- stances they are intended to exclude, very soon become still rougher by the deposit of a sediment composed of all kinds of impurities carried by the waste water, so that the fit can never be ti^ht, of whatever substances the valve and seat Pig. 71. Fig. 72. Fig. 73. be made. When somewhat stiffened with age the sphere becomes still more defective in shape, and its weight can- not press out the irregularities of the surfaces. When the valve and seat are wet, a seal may sometimes be formed against the passage of air, but the seal is due to the water and not to the valve, and the water seal alone would be equally efficient, since, as we have already seen, we have 163 Plumbing and Household Sanitation. to do with air and gases in their normal condition and not under pressure. None of these traps are siphon proof unless ventilated. Like the gravity valve, they resist evaporation under the ventilating current for a long time, and in this respect are better than the floating ball trap, for the gravity ball and valves, as will be seen by referring to the drawings, hinder the ventilating current from licking up the water seal beneath the ball. The floating ball offers no such re- sistance. Evaporation goes on as rapidly as if no ball ex- isted. This is, under the present law requiring special trap ventilation, a matter of great importance, though one which is generally overlooked in comparing mechanical seal traps with one another. Fig. 82 represents a gravity ball or valve trap designed for kitchen sinks. It is intended to take the place of the unfortunate bell trap, now so universally condemned. It consists of a lead receiver with a brass grating on top. The receiver holds about half an inch of water, into which the hollow valve or ball dips. The valve has a circular rim around its bottom, corresponding to the groove in the re- ceiver which holds the few drops of water, and with it forms the feeble seal. The quantity of water is so small that evap- oration easily destroys the seal in a short time, even without special vent. The trap is extremely liable to become clogged with the substances passing through kitchen sinks. This often leads to a removal, by ignorant servants, of both valve and strainer, which, of course, destroys the seal. Such a trap is little better than the ordinary bell trap, even though there is the slight advantage claimed for it by Baldwin Latham that the bell is not attached to the strainer. All such forms of sink traps are to be unconditionally condemned. Figs. 83 and 84 represent the ordinary bell sink trap, and Fig. 85 is an improvement thereon in having the water seal independent of the grating. In both of these traps the water seal is too small. Both are destroyed by the 164 ' if 1 tf-^ k 111 \\3 \ \jffTf\ Pig. 74. Fig. 80. Fio. 143.— Turner's Trap, Fig. 75 Fis. 79. 165 Plumbing and Household Sanitation. slightest disturbance of atmospheric pressure in the waste pipes, and are condemned by all sanitarians. This trap, Fig. 81, is far too expensive and complicated ever to become popular or practical, and is no less of a cesspool than the common round or pot trap,which is equally effective in excluding sewer air. The seal of this trap can- not be broken by siphonage, nor can that of a pot trap, if it be made large enough. Yet the law requires the ventilation of both of these traps. The mercury seal trap must be constructed of some material not easily corroded by mercury or water. Figs. 74 to 79 show five more ball traps, described by Mr. Gerhard. The first has a double gravity valve. "A glass in the upper side of the trap," says Mr. Gerhard, ''enables one to inspect the working of the ball valves, which is as follows : When in rest there is, in addition to the water seal, a mechanical seal, which is half immersed in water. The second ball valve at the outlet also shuts off by its weight, but in case of undue pressure this would tend to lift the ball, leaving around it a waterway through which the water flows out. In rising, the first ball touches the second ball, which is also lifted, to allow the water to pass freely. As soon as the discharge ceases, both valves drop back into their seat." Under siphonage the valve nearest the outlet, and under back pressure that on the inlet side, will close, and so long as the trap continues clean these balls would aid in protecting the seal. But better methods have now been devised for accomplishing this, and the two balls form a double impediment to the water scour. The remaining drawings in this slide show Mr. Gerhard's improvements in ball traps, which at that time were val- uable, but which have since been supplanted by improved water seal* The last is certainly ingenious and as good a *Wm. Paul Gerhard "Drainage and Sewerage of Dwellings." Win. Comstock, N. Y. 166 Traps. mechanical trap as could be devised for resisting siphonage or back pressure. Figs. 86, 87 and 89 represent the McClellan Trap Vent, a simple device to take the place of the back vent pipe. Figs. 86 to 88 give sections of the device, and Fig. 89 shows the manner in which it is connected up with different fixtures. Siphoning action lifts a small cup out of a mercury seal and allows air to pass from the room under the cup as shown by the arrows to break the partial vacuum in the soil pipe. This device is much better than back venting. But where grease would accumulate in the throat of the back vent pipe it would here, and the mechanical parts are open to the ob- jections already referred to in other mechanical traps. Fig. 66. Fig. 89. 167 Fig. 90. Common "Pot." "Round" or "Cesspool" Trap. CHAPTER XL Water Seal Traps. 1UATER seal traps bear the same rela- tion to mechanical traps that the hopper water-closet bears to pan, valve and plunger closets. They ac- complish their work of removing the wastes and excluding sewer gas much more perfectly by the simple action of the flushing stream, and by the water seal which it forms, than do the complicated machines already described, and they must be placed far ahead of them. Here again the leading sanitarians are in accord ; but as is the case with hopper closets, so it is with water seal traps, there is the greatest difference in the manner in which the different kinds perform their duties. Our first general division of water seal traps is into (a) Sediment or Cesspool Traps, and (b) Self-Cleansing Traps. (a) Sediment Traps. — Sediment traps may be designated as those whose inner surfaces are not cleaned by the scour of the water passing through them, but which gradually be- come coated with a deposit of filth. The deposit is due to the improper form and size of the water passages, which sometimes cause the current to pass through them slug- gishly and without exerting upon them sufficient friction to keep them clean, and sometimes furnish chambers or pock- ets in which no movement at all takes place. We have subdivided sediment traps into (i) Air- Vent Traps, and (2) Reservoir Traps. 168 Traps. (i) Air-Vent Traps. Fig. 91 represents a trap having an air valve. The ex- clusion of soil-pipe air, therefore, depends entirely upon the accuracy of the fit of this valve alone, without the aid of water. We have already explained that such a valve could never be made gas tight, even when new, where its weight is expected, as here it must be, to perform its purpose of protecting the water seal below from siphonage. Such an air valve, if applied at all, should be placed above the trap far enough from the waste water to be beyond the reach of contamination therefrom. As here placed, the hinge ■5 Kb UL Fig. 91. Air Vent Trap. Fig. 91b. Morey's Air Vent. would quickly become corroded enough to deprive it of the sensitiveness of action necessary to prevent the de- struction of the light body of water in the trap by siphon- age. Nevertheless, the idea underlying this trap is good; namely, to apply a very small air valve far enough above the trap seal to be entirely out of the way of water spat- tering and sufficiently sensitive to supply air to the waste pipe before siphoning action can overcome the feeble in- ertia of the water seal. It is the principle of the Morey and McLellen vents. (2) Reservoir Traps. Figs. 90 to 105, inclusive, represent various forms of 169 Plumbing and Household Sanitation. sediment collecting traps. The most famous in this coun- try is the pot trap (initial cut), Fig. 90. The unfortunate D trap, common in England, is shown in Figs. 92 to 98. This D trap is as much despised here in America as our favorite pot trap is in England. It is difficult to account for the national fondness for either of these abominations, now very cheaply made by machinery, after so much better de- 1) Fig. Old Fig. 92. Fig vices have been furnished. But both forms, as well as the globe trap (Fig. 100) and bottle trap (Fig. 91) are hard to siphon when the size of the body is made large enough in proportion to that of the inlet and outlet pipes, and this fact, together with the ease with which they could be manu- factured by hand on rainy days, has made them favorites, 170 Fig. y4. Fig. 95. Fig. 96. Fig. 98 Fig. 100. Plumbing and Household Sanitation. in spite of the absence of all science in their form and con- struction Although the pot trap is liable to collect sediment and become at times very foul within the cesspool chamber, it may, nevertheless, be made antisiphonic, and, if the walls are sound, the foul gases within it cannot escape into the house under normal conditions. All they can do is to re- main in the trap until they are driven out by the next cur- rent of water that passes through it ; only with unventilated soil pipes do these cesspools become a source of serious trouble. Yet if a choice had to be made between the evils of an unventilated pot trap and a ventilated siphon trap there should be no hesitation in preferring the former. The bottle trap (Figs. 91 and 100) are equally good with the floating ball trap of equal size in resisting siphonage and in every other respect, and they are much to be pre- ferred to it, inasmuch as they are not encumbered with any mechanical part. Fig. 91 bis shows an inverted bottle trap, the interior pipe becoming the outlet instead of the inlet. In this case, the outlet pipe is sometimes flared out, trumpet shaped at the end. This may somewhat increase its resistance to siphon- age, but it also evidently tends to obstruct the water flow, and forms a nucleus for the collection of sediment, hairs, lint, etc. A better way to increase the antisiphon feature is to increase the diameter, if a bottle trap is to be used at all. Fig. 62 is an old form of D trap called the "Goose" trap, a cesspool trap of rarely appropriate name. Figs. 94 to 99 represent some cesspool traps at the Mu- seum of Hygiene at Washington, and described by Mr. Glenn Brown, architect, some of them having been pre- sented by Mr. S. Stevens Hellyer of London. They show tHe heavy deposits formed in these unflushed cesspools and 172 Plumbing and Household Sanitation. the chemical action on their metal work, especially where soil pipes are unventilated under abnormal conditions. In the first figure, which is a water-closet trap, the inlet pipe is almost closed by deposits, and the waste pipe en- trance (A) from another fixture is completely closed up. Fig. 97 shows a piece sawed off from the bottom of a D trap. Over a third of the entire area of the trap seems to have been taken up with the deposit. Fig. 98 is a section of a lead D trap having an incrusta- tion below the water line averaging over an inch in thick- ness. Two waste pipes entering below the water line were nearly closed by deposits, the waterway remaining in them being not over ^ inch in diameter. The analysis of the incrustation in this trap showed calcic phosphate, 37.12 per cent; plumbic phosphate, 1.45 per cent; calcic carbonate, 32.11 per cent; volatile and organic matter, 17.82 per cent, and water, 11.50 per cent. Figs. 95 and 99 show waste pipes completely closed in traps which had been in postion forty-five or fifty years. Fig. 101 is a pot trap having its inlet and outlet pipe con- nections arranged in such a manner as to improve the scouring action of the water passing through it. But a fix- ture having its outlet large enough to fill the waste pipe "full bore" and constructed so as to be discharged "full bore," must be used with such traps, as indeed with all traps, if the cleansing power of the flush is to be of any service. Figs. 102 and 103 show a bathtub trap.* Its purpose is to permit of cleansing it from the floor level. Made of suf- ficient diameter it would easily resist siphonage and is very convenient where it is necessary to sink the body of a trap between floor joists. Figs. 104 and 105 show ordinary pot traps in the same position. 'Made by the Webb Manufacturing Co. of Boston. 173 Plumbing and Household Sanitation. Fig. 102. Fig. 103. Fig. 104. CHAPTER XII. Street Gullies and Siphonable Traps. Fig. 107. THE next figures are taken from Bald- win Latham's "Sanitary Engineering" and show sediment traps used for |dfStreet Gullies. These traps ought to ^gradually disappear from use and will do so as soon as communities see the importance of building good sewers and properly ventilating them. The street sewer inlets will then serve as sewer inlet vents and the traps will be done away with. The silt-basins must also disappear with the disuse of horses. Automobiles will require perfectly smooth pave- ments, which are not entirely without drawbacks now, on account of the danger to horses from slipping. These smooth pavements will then be kept perfectly clean and the ventilating openings into the sewers will be very simple and inexpensive. Until such time, however, street gullies and sediment traps will be used, and the drawings show the principle upon which they are constructed. "Gullies are liable to fail in times of frost, especially in very cold countries, as the gullies and traps get completely frozen up, and, when a sudden thaw takes place, they are found locked up with ice, so that the water cannot readily escape, and the streets, in consequence, get flooded. The remedy for this is to remove the water in the gully as far as possible from, the surface, and the gullies are constructed 175 Plumbing and Household Sanitation. with special reference to the breaking up of the ice in the traps should it accumulate. Figure no represents the sec- tion of a street gully which has been used at Carlsruhe, Ger- many. The gully is made in two portions, with a trap in the division wall. Should the trap get frozen, the stone S is removed from that portion into which the trap discharges, and a suitable tool may be inserted to break up the ice. * * * In all cases gullies are liable to become untrapped Fig. 106. Fis. 112. Fig. 113. from leakage or from evaporation, therefore, to insure the integrity of the traps, they should have the water constantly renewed in dry weather. * * * All gullies should be reg- ularly scavenged, not less frequently than once every six or ten days, as matters are often passed into them, which decay and give off an offensive effluvium if left too long in the gully. * * * Gullies are usually provided with grated coverings * * * which should be arranged at right angles to the traffic, or otherwise narrow-wheeled ve- 176 Street Gullies and Siphonable Traps. hides are liable to get injured in the openings between the bars of the gratings.* Figure 106 is a representation of a gully trap which is an improvement upon the common Bell trap, the bell not being attached to the cover, but being loose, and having a perforated bottom and dropping down on the center cone D. The top grating is hinged and can be raised so that the trap can be easily cleaned out. B is the level of the street surface, and C of the water. The arrows indicate the direc- tion of the passage of the water to the drains. Figure 107 is a London gully-hole with a cesspool con- structed under the sidewalk in order to facilitate its cleans- ing in narrow streets of great traffic. The solid matter is collected in the bottom of the cesspool and removed from time to time through the stone manhole in the sidewalk. Figure 108 is a larger gully with cesspool under the side- walk. It contains room for a large amount of road detritus to be periodically moved as described for Fig. 107. Fig. 109 is a street gully with earthenware trap. The gully it- self is made of concrete in one piece, strengthened with wrought iron bands cast within the concrete. This con- struction has been used in the city of Dantzic where the climate is very severe. Figures in and 112 are gully traps suitable for yards, but the curved bottom of the latter with the outlet near it, renders it liable to transmit detritus into the sewers where a large volume of water passes through it. Figure 113 shows a double trap London street gully, the smaller catch-pit is not so easily evaporated out as the larger one, which is more exposed, and the emptying of the larger one still leaves the gully trapped. Figures 114 and 115 show a cast-iron gully having sev- ! Baldwin Latham. 177 Plumbing and Household Sanitation. eral good points where traps are desired at all. First it has a trap which is as reliable as possible at all times, the usual traps losing their seals when the level of the water is reduced by the removal of deposits. Second, very little evaporation goes on in summer, and freezing in winter is Fig. 122. Fig. 123. impeded. Third, there is ample space for road detritus., Fourth, it has a flushing aperture in the small trap. Fifth, it is economical and requires no brickwork in setting. Figure 116 shows a gully used by Mr. Denton for many years, having advantages similar to the last. Finally Figs. 178 Street Gullies and Siphonable Traps. 117 and 118 show gullies having removable sediment boxes. The gratings are made separate for convenience in casting and in lifting off. The boxes above the trap lessen evapora- tion in dry weather and can be removed and emptied into the scavenger's cart readily by one man. The next figures show a number of disconnecting house traps described by Denton, all being more or less cesspools, with square top. Figure 123 is a horizontal house trap. Fig. 124. Fig. 126. All should and will be done away with as fast as the people learn the value and economy of well ventilated sewers. The slide also gives a number of grease and sink traps. Figure 121 is a species of grease traps having a catch- basin at the bottom. Fig. 122 is an earthenware sink trap Figure -124 is a rainwater pipe trap which, however, can not be depended upon unless means are provided for con- stantly renewing the water therein. Figure 125 is a running 179 Plumbing and Household Sanitation. house trap with gully combined. A gully trap so used will always be sure of a seal while the house is occupied, be- cause it takes the house waste and is not dependent upon rainy weather. Fig. 126 is another gully trap showing how it may be ventilated by a pipe rising along the outer wall of a house. Fig. 130. Fig. 129. Fig. 128. n p» Fig. 131. Fig. 134. Fig. 127 shows a triple seal trap, used in England, and is introduced to show the madness to which main house trapping is sometimes carried. The water in this trap oc- cupies two compartments separated from each other de- signed to prevent the one seal from polluting the other if 180 Street Gullies and Siphonable Traps. the water in it should in any way become foul. The middle part of the trap receives the surface drainage, and also pro- vides an escape for any sewer air which might be forced through the outer seal ; all parts open directly into the outer air through gratings. The three dips are intended to afford extra security against the passage of sewer air. This trap is, of course, very objectionable on account of the great obstruction it offers to the passage of the drainage, and of its expense. Self Cleansing Traps. are those which are scoured throughout by the water which passes through them. They may be subdivided into (i) those which lose their water seal under the action of siphon- age or momentum, and (2) those which are capable of resisting such action. (1) Siphonable Traps Figures 128 to 134 represent different forms of siphon- able traps. A very feeble suction is all that is necessary to break the seal of any of them. The modified forms possess no appreciable advantage over the common S trap of equal depth of seal in this respect. Fig. 134 is an S trap with a small sediment chamber at its bottom. This chamber was introduced with the idea that it would give the trap greater resistance against siphonage. It has, however, no advantage whatever in this direction, since its enlargement is all below the seal proper. Fig. 135 represents a complicated device for replenishing the seal exhausted by siphonage, evaporation or other cause. The device would evidently soon become inoperative, and is too expensive and delicate to deserve more than a passing no- tice. Fig. 133 shows the manner in which the ventilating 181 Plumbing and Household Sanitation. opening of an S trap becomes clogged sometimes to a height of more than two feet from the mouth, and the same would result with the water supply pipe intended to refill the trap in Fig. 135 because it could evidently never be under water pressure. Figures 136 and 137 are other illustrations of an excess of ill-directed zeal. The purpose is to refill on S trap auto- matically after siphonage, a small reservoir chamber being attached to the trap in such a manner as to deliver to it through atmospheric pressure a fresh supply of water when- ever its level in the trap seal falls slightly below the normal. It works on the principle of the inverted bottle chicken Fig. 135. feeder, and is itself replenished by a small feeder pipe operative when the supply cock of the fixture is opened for use. This complicated and costly device was conceived many years ago when the fear of sewer gas was at its greatest. It is true that the water pressure would be likely to keep the small openings in the reservoir chamber free from deposit and the trap well scoured out, but the trap might be siphoned while the fixture cock was not in use for a considerable length of time so that the entire device would serve only to inculcate a false sense of security, even though evaporation might not empty the supply vessel in a year. 182 Street Gullies and Siphonable Traps. Fig. 136. 183 CHAPTER XIII. Seal Retaining Traps. We have considered briefly the various agen- cies which tend to destroy . j the seals of traps, and ss have presented several vi- {^ tal objections to the meth- ods of protection gener- ally attempted. Fig. 138. Internally all kinds of mechanical seals, balls, gates and valves, both single and double, as shown in Figs. 64 to 81, inclusive, have been tried. Externally in- genious and complicated devices for refilling the seals after their destruction, like that shown in Figs. 135 and 136, have been attempted. But all of these devices have failed for want of simplicity and reliability. Finally the "back vent" pipe was conceived of, and for a time it was supposed that the great remedy had been at- tained. A few rough and unscientific laboratory tests made on siphonage, which seemed to corroborate the idea, at once gave rise, in several large cities, to a law rendering special trap venting obligatory. At the time this law was enacted the common "round" or "pot" trap of large size had shown itself to be capable of resisting siphonage when new and clean, but it was recognized that under some conditions, as when used with kitchen and pantry sinks, clogging was cer- tain in time to render it inoperative. The object of the vent pipe was to afford protection without the use of these 184 Seal Retaining Traps. cesspool traps, but the practical result has been that cess- pools have become, since the enactment of the law, more prevalent than ever, because not only has the use of the pot trap, under various changes of form and name, continued undiminished, but the mouth of the vent pipe has added a cesspool to traps which were otherwise substantially self- cleaning, as has already been shown. Thus not only has the original purpose of the law been frustrated, but the very evil it was intended to remove has been actually augmented by it. The pot trap is converted by grease into an S trap, and the S trap by the same agency acting in the mouth of the vent pipe, into a cesspool trap. The vent pipe was applied to protect the S trap, but is it- self destroyed by the very same agency which destroyed the pot, and the only wonder is that this inevitable result was not anticipated before the law was passed. Having now found this belief in back venting to be fallacious, safety must be sought in some other direction. Siphonage must be guarded against, not by adding to the trap a limb of indefinite length and connecting it with the external air, but by forming the trap itself in such a man- ner that its own water-way shall serve as a special air-vent passage, and permit the air of the room to supply the par- tial vacuum in the soil pipe without drawing the water out of the trap before it. In constructing the trap provision must be made also for resisting back pressure, evaporation, capillary action, leak- age and all other adverse influences. If a trap can be devised which shall be as self scouring as a straight pipe of the size of the waste pipe itself, and at the same time be capable, unvented, of resisting a siphoning strain powerful enough to completely empty an S or small pot trap fully vented in accordance with the law, and if the construction of this trap is such that it forms its own 185 Plumbing and Household Sanitation. vent pipe and causes fresh air to pass through its own body whenever it is used and whenever siphoning action occurs, so that it actively assists the main soil pipe vent in aerating the waste pipe system in the most effective manner ; then it becomes clear that the continuance of this law on the statute books is a very gross imposition upon the public. When, in addition to this, we know that the vent pipe is utterly unreliable on account of clogging and other influ- ences already fully described, and that it involves the very positive and important objection of rapidly destroying by evaporation the seal it was intended to protect ; where other simpler methods now known are entirely free from these difficulties ; the enforcement of such a law becomes an in- excusable outrage upon the public, whether such enforce- ment be due to selfish private interest or unjustifiable igno- rance, and the investigation of the whole matter by an im- partial commission appointed by the Federal, State, or Mu- nicipal authority, becomes a very serious duty in behalf of the people which has already been far too long neglected. Although it has always been declared impossible, from the nature of things, to render a simple unvented S trap absolutely secure against siphonage this has nevertheless now, in effect, been fully accomplished. Evolution of a Permanent Anti-Siphon Water-Seal Trap. To obtain these results, without internal complication or external aid, is only possible by taking full advantage of the various laws which govern the action of fluids in plumbing. The difference in the specific gravity of air and water, and the consequent difference of momentum of the two fluids under equal rapidity of motion, and the relative attractive and cohesive forces of the particles of the two fluids, give 186 Seal Retaining Traps. us reliable means of separating the air from the water in their passage along the inner walls of the trap as simply and unfailingly as chaff is separated from the grain in the winnowing machine. I have given as the second of the three methods tried for protecting the seals of traps from loss by siphonage, the use of a large unventilated "pot" or "reservoir" trap. I have shown that a small pot trap will not resist siphonage, and that none which is less than eight inches in diameter can be relied upon in all cases ; that a five-inch pot trap might sometimes be siphoned out by discharges from fix- tures under conditions which may occur in practice; that a four-inch pot trap siphons out much easier; that an ordi- nary three-inch trap has very little resisting power, and that two and a half inch and two-inch traps are altogether useless, and but little more than S traps. But unfortunately the larger forms of pot traps are, as has been said, not self cleaning. They are cesspools and violate one of our main principles of plumbing which pro- hibits the retention of decomposing waste matter anywhere within the system. They are also very bulky and expensive in use of material. In order to better study these movements, we have had a large number of traps constructed in whole and in part of glass. The initial cut, Fig. 138, shows one of our experimental glass traps in perspective, so constructed. The body is thirteen inches square and an inch and a half deep. The inlet and outlet arms are made of inch and a half pipe. The inlet end descends below the bottom of the drum instead of entering the side, as is customary. Under siphoning action the seal standing in the inlet bend rises into the drum and simply stands one side while air passes through the trap from the fixture above the 187 Plumbing and Household Sanitation. water in the drum, as shown by the arrows in the drawing, and breaks the partial vacuum in the soil pipe. The storm having blown over, the water seal quietly returns from the drum or reservoir chamber into the bend and restores the original conditions as a reed rises after the fury of a hurricane has passed. Thus the trap becomes its own back vent pipe, a back vent pipe which has no inaccessible body waiting for mis- chief, which provides entire security, and yet which adds absolutely nothing to the expense. As will be seen, a small portion of the water in the trap will be thrown out at the first application of the siphoning strain, but as soon as the level of the water in the reservoir chamber has been lowered a little below the overflow point, far enough to provide for the wave action produced by the air blast, no further loss of water can be occasioned even by the severest strain that can be brought to bear upon it. This trap was found capable of withstanding a strain severe enough to empty an S trap fully vented under the most favorable conditions with a new clean vent the size of the bore of the trap and only fifteen feet long. It per- fectly illustrates the fact that the principle of resist- ance to siphonage lies not in depth but in breadth of seal. The maximum of strength comes with the maximum of horizontal dimension, but with a minimum of height. The trap is, however, still open to the objection that it is not self-scouring. The sediment chamber is not so large as it would be in a deeper drum trap. The cesspool feature has been eliminated only in one of its dimensions. Fig. 193 shows the manner in which a pot trap of this form, though absolutely antisiphonic, could clog with grease under a sink. The third method of obtaining the desired security is, 188 Seal Retaining Traps. as stated, to obtain some form of trap which shall be both antisiphonic and self scouring at the same time. In our experiments with pot traps of various diameters, from eight inches down to two inches, we have found that with traps of equal depth their resistance to siphoning action very rapidly increased with the increase of their diameter; that with traps of equal diameter their resistance to capil- lary action increased with their depth ; that resistance to back pressure increased with the increase of water capacity of the trap and with its depth below the fixture it serves; and that resistance to fouling action and clogging increased as the sectional area of the body of the trap approached that of its inlet and outlet arms ; and that, finally, resistance to evaporation increased with the increase of water capacity of the trap and of its distance from air currents. I have moreover lately found that a shallow seal trap may be de- signed in such a manner as to protect the seal of a water closet trap from siphonage, as will hereafter be shown. From this it would appear, at first thought, that to ob- tain a trap capable of afTording the maximum resistance to all these adverse influences at once and under all conditions would be impossible, because the desiderata above enumer- ated seem to be in direct conflict with one another, a large diameter being needed to resist siphonage and a small one to resist clogging, while evaporation and capillary action seem to demand a deep seal and thorough scouring, and water closet trap protection a shallow one. But a closer in- vestigation will make clear that these disiderata are not necessarily incompatible with one another, as the following experiments and reasoning will show. The trap must be so formed, in the first place, that its sectional area shall in no place exceed the area of the fix- ture waste pipe which it serves, because otherwise it would not possess the maximum of self scouring power, 189 Plumbing and Household Sanitation. This requirement confines us to the use of some form of plain piping, either straight or bent, in the construction of the trap. In the second place it is evident that a sufficient amount of this piping will be required in the formation of the trap to provide the necessary water capacity for resistance to back pressure and evaporation. In the third place all the piping used must be on a hori- zontal plane in order to preserve the required minimum depth of water seal. Finally, for the purpose of insuring against loss of seal by capillary action, the seal of the trap must be separated from its connection with the drain pipe by a distance great enough to offset the maximum of capillary forces ever en- countered in plumbing practice. The first form of trap answering to these requirements with which we experimented was, therefore, the simplest form, namely, that of a straight pipe placed horizontally, as shown in Fig. 139. This trap consists of the seal proper shown on the left side of the figure, which is made of i^-inch bent tubing, the seal being not over a half an inch in depth ; a long hori- zontal body consisting of a plain round pipe likewise i>4 inch in diameter, or of exactly the same sectional area as that of all parts of the seal tubing; and at the opposite end of this pipe the sewer connection piece, which is again of sectional area everywhere equal to that of all the parts of the trap. I call the first part of this trap the "trap seal proper," the second, the "reservoir chamber," and the last, the "outlet connection." The outlet connection has its overflow point }i inch above the bottom of the reservoir chamber, so that when this chamber stands full of water the entire depth of water seal measures only 1*4 inches. 190 i kin Fig. 153. Fig. 154. Figs. 147 to 161, inclusive, show the various forms we have examined, and in Table I the test made on some of these forms are recorded. The results of the tests may be briefly summed up as follows: 198 Seal Retaining Traps. Seal Retaining Traps, (i) With traps of the kind under consideration the power of resistance to siphonage is in proportion to the horizontal length of the waterway in. the trap. The largest \ 1 '% I ' ' L 1 Fig. 155. Fig. 15( V L- ■ Fig. 157. Fig. 158. Fig. 159. Fig. 160. Fig. 161. is capable of resisting the most powerful siphonage that can possibly be brought against it on any apparatus which can be built for making a plumbing test of which we are aware, 199 TABLE I. EXPERIMENTS ON SIPHONAGE. SEVEREST STRAIN. Showing Aggregate Loss of Water in Traps in Fractions of an Inch After Each Siphoning Action. Traps Tested Number of Each Test. 2 3 4 5 6 10 S-Trap Fig. 143 iy 2 in. Seal 10 ft. Vent & One Return Bend Seal Broken Trap Emptied* 4-inch Pot Fig. 144 3*4 in. Seal 2 in. out 2 1-2 in. out 2 3-4 3 Seal in. in. Bro- out out ken 4 inch Pot 20 ft. of Vent Pipe & 5 Return Bends 3-4 in. out lin. out 1 1-2 13-4 2 2 1-4 2 3-8 do. do. do. Long Trap Fig. 139 Seal Broken S-Trap 2i/ 2 ft. Seal Seal Broken S-Trap 4y 2 ft. Seal Seal Broken S-Trap 6y 2 ft. Seal All but 10 in. out All but 6 in. out do. do. do. do. 13 in. Square Trap. Fig. 193 5-16 in. out ll-32in. out 3-8 do. in. out do. do. do. do. do. do. 13 in. Square Trap. Fig. 141 1-4 in. out 3-8 in. out do. do. do. do. do. do. 13 in. Square Trap. Fig. 147 1-16 in. out do. 1-8 do. in. out do. do. do. do. do. do. 13 in. Spiral Trap. Fig. 178 3-8 in. out 1-2 in. out 17-32 do. in. out do. do. do. do. do. do. lOi^ Spiral Trap. Fig. 183 1-2 in. out do. do. do. do. do. 10y 2 in. Spiral Fig. 180 1-2 in. out 9-16 out do. do. do. do. do. 8^4 in. Spiral 1-2 in. out 3-8 in. out 7-16 do. in. out do. do. do. do. do. do. 7 in. Spiral 1-2 in. out do. do. do. do. do. do. do. do. do. 6!/4 in. Spiral 1-2 in. out do. 916 5-8 in. out. in.i do. 3Ut. do. do. do. do. do. 6 in. Spiral 3-4 in. out 7-8 in. out 1 do. >Only 1-8 inch of water left in bottom ofTrap. 200 Seal Retaining Traps. and much more powerful than any that can be brought to bear upon it in plumbing practice. This same statement holds good down to the six inch size, the only difference being that the amount of water forced out of the reservoir chamber by the strains will be slightly greater in the smaller than in the larger sizes, as will be seen by reading the table. The two smaller sizes, namely, the 7 inch and the 6 inch, will resist any siphoning action, however long continued, which can be encountered in actual plumbing practice. By slightly increasing the depth of the trap, in these smaller sizes, however, the resistance can be made to ap- proximate that of the largest sizes. Thus by increasing the depth of the 7 inch trap by half an inch its resistance can be made substantially equal to that of the 10 inch and the 13 inch traps, and by increasing the depth of the 6 inch trap by an inch the same result can be attained in this case. (2) The variations in arrangement of the partitions shown in the various figures given above, do not essentially affect their power of resistance to siphonage nor the cost of their construction. Figs. 162 and 163 show two other arrangements of the partitions. The corners of the partitions may be rounded as shown in these drawings without greatly affecting the re- sistance of the trap, a slight increase in the length of the water-way fully restoring any loss of area thus occasioned. Fig. 164 shows four ordinary S traps connected together. I have drawn them . for the purpose of comparison with Fig. 163. Such an arrangement of S traps would, of course, result in "air binding." But by venting them at the crown this is obviated. Now the only difference between these two arrangements 201 Plumbing and Household Sanitation. is that in Fig. 164 the S traps are placed vertically and in Fig. 163 they are placed horizontally. The forms and sizes of the traps in both cases are absolutely the same. But the entire character of the S trap has by this simple change of position become marvelously and radically altered. Fig. 162. Another arrangement of the partitions. Fig. 163. S-traps placed horizontally. Fig. 164. S-traps placed vertically. 202 Seal Retaining Traps. In its ordinary vertical position the trap is now known to be utterly unreliable and therefore in eifect worthless, presenting, as it does, the feeblest possible resistance to all the adverse influences which tend to destroy a water seal in plumbing, and for this reason the common S or siphon trap should never be used except for water closet seals, and then only under conditions of arrangement which will ren- der their seals secure and reliable. In its horizontal position, on the contrary, it becomes absolutely invulnerable, and acquires all the qualities to be desired. Thus the feat of rendering an S trap antisiphon without the aid of a vent pipe, as claimed at the beginning of this chapter, has been accomplished. By this treatment our S trap becomes in effect vented through its own inlet pipe, whereby the entire volume of fresh air needed to supply the strongest siphonage ever encountered and to ventilate the waste pipe system is made to pass directly through the body of the trap itself without the slightest danger of destroying its seal in its passage. (3) We find, however, that the free and rapid discharge of the waste water in normal use is diminished in proportioi as the turns required in its passage through the trap are abrupt and varied. Thus the traps shown in Figs. 147 and 162 retard the flow more than those shown in Figs. 138 and 141, and the oppor- tunities for sediment deposit are greater in the latter than in the former. Hence of these forms the former have two important advantages. Experiments were also made on horizontal traps with combinations of curved and straight partitions as shown in Figs. 165 to 177, inclusive. They showed about the same power of resistance as the traps having all rectangular par- titions, but were, for the same reasons, subject to the same defects. 203 Plumbing and Household Sanitation. Fig. 165. Fig. 166. Fis. 167. Fig. 168. Fig. 169. 204 Seal Retaining Traps. Fig. 170. Fig. 171. Fig. 172. Fig. 173. Fig. 174. Fig. 175. Fig. 177. Figs 164 to 177 inclusive. Horizontal Traps with Combined Curved and Straight Partitions. We have found that these defects can be obviated by taking advantage of the principle of centrifugal force. Ac- cordingly we constructed the partition in the form of a spiral as shown in Figs. 178 and 179. 205 Plumbing and Household Sanitation. This improvement constitutes our third step, and in it we have attained a form which combines the advantages of all the preceding ones and eliminates completely their defects. We can reduce the horizontal dimensions as much as be- Figs. 178 and 179. Third Step. Plan and section of Horizontal Trap with Spiral Partitions. fore without destroying the power of the trap to withstand the severest tests of siphonage. We have done away with the comparatively clumsy method of using abrupt turns and baffle walls to separate the 206 Seal Retaining Traps. air from the water when siphoning action takes place, and have substituted for it the simpler and more scientific and effective agency of centrifugal force. Air under powerful siphonage rushes through the trap with tremendous speed, causing some of the water in the reservoir to whirl around with the air like a miniature whirlpool and cyclone. The water, being the heavier of the two elements, is thrown outwards by its spiral movement against the outer walls of the partition, while the air hugs the inner walls because along them lies the quickest and easiest outlet to the drain pipe where the partial vacuum to be filled by it exists. This action of the two fluids is easily followed by the eye if the upper side of the experimental traps be made of glass. It is made stiU more plainly discernible if lumps of earth, small stones and other substances a little heav- ier than water be mixed with it. These are clearly seen to hug the outer walls as they whirl around on their way to the outlet, while the air bubbles, always present in the water at the time of siphoning action, seek the inner side or more direct passage outwards, which is for them the line of least resistance. The resisting power of this trap is, as shown by the table, as great as that of any of the preceding traps, while its form permits of a much more rapid discharge than the others in proportion to the length of its waterway, and it has the maximum of scouring action, and absolutely no obstruction or baffle in any way of the water discharges at any point beyond what is encountered in a perfectly straight smooth pipe. It has a sufficient volume of water to withstand back pressure and evaporation, and the distance between the trap proper and the drain outlet is sufficient to obviate capillary action. I believe, therefore, that in this we have attained the prin- ciple of the perfect anti-siphon plumbers' trap. 207 Plumbing and Household Sanitation. Examined for friction, or self scouring properties, these spiral traps showed themselves, as might be expected, far superior to the others, as indicated by the friction tests recorded in Table III. TABLE III. Experiments on Water Scour. Showing Time in Seconds Required for Water in Cistern Shown in Fig. 241 to Pass Through Traps. Number of tests. Traps tested. 1st Test. 2d Test. 3d Test. Sec. Sec. Sec. 4-in. Pot Trap, 3 1-2-in. Seal . . 25 24 25 Straight Pipe 22 22 22 7 1-2-in. Pot, 4-in. Seal 32 32 32 13-in. Sq. Trap, Fig. 138 21 21 21 13-in. Sq. Trap, Fig. 141 35 35 34y 2 13-in. Sq. Trap, Fig. 147 55^ 55]/ 2 13-in. Spiral, Fig. 178 27 27 27 11-in. Spiral, Fig. 181 32 32 32 11-in. Spiral, Fig. 180 32 32 32 11-in. Spiral, Fig. 182 28 28 7-in. Spiral, Fig. 185 30 30 29 The 13-inch spiral trap, tested on the apparatus shown in Fig. 190, discharged the 12 gallons of water from the tub in less than half the time required by the rectangular trap of Fig. 147, 27 seconds being required for the former and 553^ seconds for the latter. The tank holding 12 gallons, the first discharged about two quarts per second, and the second less than one quart. Moreover, it required from 5 to 10 seconds for pieces of paper, small lumps of earth and other articles thrown into the water to pass through the rectangular trap, whereas these matters were whirled through the spiral trap in less than half the time. Heavy substances, like small lumps of iron and lead, were retained in the rectangular traps, but were always easily and quickly whisked through the spiral trap and carried over into the waste pipe. 208 Seal Retaining Traps. Now the scour exerted by the water in passing through the reservoir chamber of the spiral trap was found to be as effective upon the walls of the chamber as upon the dip of the trap proper, because it is in the dip of a trap that heavy matters are most likely to be caught and retained, not only because the bend is most sudden at this point, but also be- cause these matters have here to be elevated by the amount of the depth of the seal, while in the reservoir chamber they have only to be pushed along a smooth horizontal surface. When the waste outlet of a plumbing fixture is very much smaller than the area of the waste pipe connected with it, the water loses its scouring force and greasy matters will gradually accumulate along the walls not only of traps but even of the straight waste pipes themselves, as has been ex- plained and illustrated in a previous chapter. Now our spiral trap is evidently no more able to resist the fouling effect resulting from improperly constructed fixtures than would be the straight waste pipe itself. But it has this all important advantage over a vented S trap, that whereas in the latter the vent pipe opening being the first part to be clogged by greasy deposits, the whole trapping system be- comes at once destroyed, and this without any warning to the user ; with the former the sediment being equally dis- tributed over the inlet pipe and body of the trap, this re- duction of the area of the waterway cannot in any way re- duce the antisiphonic character of the trap, because it simply converts it into a smaller trap, having the same relative properties and principle of action. Indeed the sediment will tend to accumulate where the resistance to the scour is greatest, which is at the dip, and in this case the area of the trap proper will constantly diminish with relation to that of the reservoir chamber, in which event the resistance to siphonage. will if anything tend to increase rather than diminish. 209 Plumbing and Household Sanitation. Therefore the trap will resist siphonage as long as there is any water way at all left in the trap. Yet when the dis- charge is entirely stopped by sediment, or retarded to a point of inconvenience, it will, of course, announce itself and necessitate opening and cleansing. The same advantage holds in the comparison of this trap with a pot trap or any other form of plumbers' trap con- structed on the unscientific and faulty "vertical" principle, which, strangely enough, is the one on which plumbers' traps have always heretofore been erroneously designed. As has already been explained in a former chapter we have subjected our traps to strains of various degrees of in- tensity, the severest being much stronger than any which could be encountered in plumbing practice, for the purpose not only of proving a degree of resistance beyond all pos- sible question on the part of the antisiphon traps tested but also of permitting a more thorough comparison between the various forms of traps under consideration, and espe- cially between unvented antisiphon traps and ordinary S and pot traps fully vented in accordance with the present plumbing laws. It only remains to determine how far it is best to contract the horizontal dimensions of our trap in order to obtain on the whole in practice the most desirable results. Our next experiments therefore were made to decide this question. Figs. 181 to 189 inclusive show the various sizes of spiral traps experimented upon arranged in the order of the tests. The endurance of each of these traps is recorded in the Table I. The depth of seal in all was the same as in all the preceding horizontal traps; i. e., 1% inches. The most that could be forced out of the 13-inch spiral trap even after numerous successive repetitions of the ordeal was Y§ inch in one set of experiments and 17-32 inch in another. 210 Seal Retaining Traps. The io^-inch spiral (Figs. 180 and 181) lost only y 2 inch under the same tests. The ioj/-inch spiral trap lost 9-16 inch. The 834-inch trap lost 7-16 inch and the 7- inch lost 9-16 inch, all under the same tests. Fig. 180. Fig. 1S2. Fig. 181. Fig. 183. Plumbing and Household Sanitation. Fig. 18 5. Fig. IS 6. D Fig. 18' TO Fig. 188 Experiments were also made with a 6-inch spiral trap, and this lost 1]/$ inch after four of these severest strains in succession. These strains long continued would have ulti- mately broken the seal of so small a trap. But it withstood all other strains as shown, and proved itself capable of easily withstanding any strains of siphonage which can ever be encountered in actual plumbing practice. The arrangement of partitions shown in Fig. 184 seemed to give results not appreciably different, so far as siphonage is concerned, from those of Figs. 180 and 182. But the sharp bends between the inlet and the outlet arms somewhat increased eddies and the friction in normal use and ob- structed the free discharge of heavy substances in the waste water. 212 Seal Retaining Traps. The small opening shown in Fig. 187 between the outlet pipe and that part of the spiral which is nearest to it pro- duced a scarcely appreciable effect in the siphonage tests. It would, however, be objectionable as a cause of complica- tion and possible obstruction and its use was abandoned. In Figs. 186 and 185 corners were rounded off as indi- cated by the black places in the drawings. This reduced the resistance to siphonage by so small an amount that its ad- vantages in facilitating scour much more than offset the loss. In Fig. 186 the bottom of the trap at the inner end of the spiral is curved gently upwards in order to do away with any sharp corners and barriers. This also improved the scouring properties of the trap without appreciable in- jury to its resistance to siphonage. Before describing our final step it will be interesting to record certain curious facts noted in making our experi- ments on our horizontal traps not heretofore observed or recorded, so far as I am aware. For the purpose of studying the movements of waste water through very large shallow traps we had the one we have shown in Figs. 189 and 195 constructed with a glass top, the length and breadth being 13 inches each and the depth i l / 2 inches. The seal proper was, as in the other cases, only half an inch deep, and the water stood Y inch deep in the reservoir chamber when full up to the overflow, making a total seal of 1^ inches under normal conditions. The actual movement of the water in this trap, under both siphonage and friction tests, proved quite different from what might naturally be expected. One might sup- pose that under the pressure (or "suction" as it is popularly called) of a powerful siphoning action, air and water would be forced straight across the reservoir from inlet to outlet arm along the line of the least apparent resistance, in a straight and rapid current somewhat as shown in our figure, 213 Plumbing and Household Sanitation. with return eddies on each side of the main current. It would also be natural to expect some such current to be formed when water was discharged through the trap with considerable force from a fixture connected up as shown in Fig. 190, where we have used a 12-gallon tank set 19 inches above the trap, to represent normal discharges from an ordinary bath tub. D Fig. 189 Fig. 189a. Plan and section of thirteen-inch trap with- out the partitions. 214 Seal Retaining Traps. The actual course of the water in these cases was, how- ever, altogether different from our theoretical assumption. Under siphoning action, the course of the water presented the appearance shown in Fig. 191. The water was projected violently upward from the inlet mouth, and, striking the Apparatus for making our experiments on friction. glass top of the trap, was reflected in a strong spray down- ward and outward with the formation of bubbles extending nearly half way across the trap. At the same time powerful waves were set up which tended to form rings around the inlet mouth spreading out- 215 Plumbing and Household Sanitation. wards in all directions to the four sides of the trap about as shown in the drawing. Fig. 191 Movement of water in our large flat trap under siphoning action. □ Fig. 192. Movement of water in the same trap under the normal discharge of water. Water from the fixtures it serves. It was for the purpose of breaking down these waves in the manner already described that we constructed the vari- 216 Seal Retaining Traps. ous arrangements of partitions in the traps we have il- lustrated. On the other hand the course of the water under a normal discharge of waste water through it from the fixture it serves, as from a bath tub represented by the tank in our Fig. 190, with which these tests were made, was even more at variance with the expected. The water, though coming with great force under the head shown in the cut, seemed nevertheless to eddy about quite leisurely and sluggishly in all sorts of directions, form- ing, to all appearances, quite meaningless and uncalled for curves and spirals, with occasional unaccountable dartings toward unexpected points. It appeared to meander about, as one might say, ''with its hands in its pockets," and not by any means to rush direct to the outlet opening with the frantic haste and decided manner we had confidently ex- pected and planned for it. Fig. 192 gives quite an accurate idea of the curious antics played by the current. The black specks in the drawing indicate pieces of heavy solid matter thrown into the water for the purpose of better studying its peculiar movements. These at times jumped about quite quickly, and at other times lay motionless for a while as if deliberately resting for some violent effort a moment later. Fig. 196. 217 Plumbing and Household Sanitation. Fig. 195 and 196 show our 13-inch glass experimental traps in perspective. The large horizontal dimensions of the first give it still the cesspool quality, and the figure shows how it would clog in time with grease under a sink. The second cut shows it divided so as to produce the water scour. Our fifth and final step consisted in constructing the parts of the trap in such a manner as to permit of economical manufacture and easy opening and closing for examination while in use. Figs. 197 to 200 inclusive show two forms adopted, the first being adapted to be placed above the floor level and the second below the floor and serving two or more fixtures at once, as, for instance, a bath tub and one or more adjacent set basins. The cover may be made of brass or of tile impervious to air and water, of octagonal shape and designed to harmonize with the tile or mosaic floor of a modern bath room. This Figs. 197 and 198. Spiral Basin Trap. Fig. 199. Figs. 200 and 201. 218 Seal Retaining Traps. form, however, the writer has not used, a later form being preferable. Figs 201 to 205 inclusive give perspective views of these traps as they would appear both closed and open. The floor trap is shown in Figs. 206, 207 and 208, serving o Figs. 199 and 200. Spiral Bath and Basin Trap, as actually constructed. Fig. 204. Floor Trap, with Tile Cover, set in Tile Work, and made tight by a large Elastic Gasket. Fig. 205. Floor Trap, shown with cover and Gasket removed. 219 Plumbing and Household Sanitation. three fixtures, namely, the bath tub, the basin and also the water closet connected with its own deep seal trap. In order to permit of this triple service the inlet arm of the trap is branched above the floor to take the basin waste Fig. 206. SP u z? Fig. 201 Fig. 208. Fig. 209. Bath Tub, showing preferable arrangement of trap entirely above the floor. Fig. 209a. 220 Seal Retaining Traps. pipe, and its outlet arm connects with the outlet of the water closet trap. If now the seal of this closet trap is made deep enough, the shallow trap will protect it unfailingly from siphonage by supplying air through its seal to break the siphoning action. This trap may be constructed under a considerable va- riety of forms, as shown in Figs. 210 to 224, to suit varying conditions, either the inlet or the outlet pipe passing through the centre of the reservoir or refilling chamber as desired. Or either arm may be placed out of the centre of the trap, as shown in previous drawings. Figs. 210 & 211. Figs. 212 & 213. 221 Figs. 214 & 21o. Plumbing and Household Sanitation. Seal Retaining Traps. Figs. 225 to 227 represent the writer's earlier trap, the "Sanitas," which he developed from the pot trap as de- ns. 226 scribed in 1884, 5 and 6, in his little works entitled "Im- proved Plumbing Appliances" and "The Principles of House Drainage." This trap has been improved upon in the later studies herein described which developed the more scien- tific "Securitas" device, and in which were avoided the defects in the Sanitas of too great a vertical extension and too many abrupt and sharp turns. By doing away with these objectionable features the "Securitas" trap has at- tained a self-cleaning property equal to that of the simple 223 Plumbing and Household Sanitation. S or ordinary siphon trap, for the bottom of the "Securitas" reservoir chamber can be curved upwards at the angle of junction with the small cross partition if desired. In prac- tice, however, it is found better to leave this angle a little abrupt in order that small articles like rings or jewels, often accidentally finding their way into a trap, may not be swept into the sewer. The corner is too small to constitute an objectionable sediment pocket, but just large enough and conveniently enough located to safeguard small valu- ables without creating any corresponding objections. Be- ing directly in the path of the strongest water flush ordin- ary sediment and greasy matters will not lodge there. This feature is sufficiently appreciated by users to justify its re- tention, although it might easily be done away with and all corners fully rounded if desired to complete the ideal round pipe section throughout. Figs. 226 and 227 show most clearly the objectionable feature referred to of the too great height of our first trap. In consequence of this unnecessary vertical extension, a larger proportion of its water seal is forced out under si- phoning action than with the later device, which for this reason proves more self cleansing with even greater siphon- age resistance, and also has the very important advantage of forming a simple and perfectly effective back vent for a deep seal water closet trap, as already described. Figs. 228, 229 and 230 show a few of the experimental traps made by the writer before the development of his Sani- tas trap, and some ineffectual efforts made in the wrong direction to take advantage of the superior specific gravity of water over air. by giving the two fluids a rotary move- ment within the body of the trap, and attempting to separ- ate them from each other by centrifugal force in a vertical plane. In these early experiments the mistake was made of adhering to the perpendicular construction everywhere 224 Seal Retaining Traps. adopted at the time and even continued in the Sanitas trap. It was only on discovering that the strength and value of a trap in every way lay in its horizontal extension that suc- cess was finally attained. Had the trap shown in Figs. 228 to 230 been built horizontally rather than vertically the prob- lem would have been settled much»sooner. It is true that Fig. 228. Fig. 229. Fig. 230. the principle of the horizontal design was, to some extent, followed in the steps leading to the Sanitas trap, but it was only partially adhered to in the final form of the trap, and yet whatever of success it has had* I attribute chiefly to the horizontal element in its design. The simplest forms of our "Securitas" trap are shown in Figs. 233 to 237. As will be seen by the drawings, all parts of the water way have an area substantially equal to that of the inlet or outlet pipes, giving it the self- scouring principle of the common S or siphon trap. *As to this matter, testimony of others known as impartial experts may seem to the reader more convincing than any self r " n '«(> the author may indulee in. and therefore one or two remarks of recognized authorities may properly be quoted here. Col. Waring-, ior instance, writes in the "Century Magazine" of the trap as fol- lows: "As an incidental result of his experiments on siphonage, Mr. Putnam, by gradual stages, arrived at the invention of a trap which seems to be a practical one, and which, subjected to tests that were sufficient to break the seal of any ordinary trap even with fair back ventilation, maintained its seal undisturbed. Mr. Putnam's trap, the form of which is illustrated herewith, stands, in its normal condition, entirely full of water. Under strong siphonic 225 Plumbing and Household Sanitation. When constructed of iron white enamelled, both inside and out, it forms a very attractive fitting, corresponding with the smooth white surfaces of the modern plumbing fixtures and bath room tile finish, and like them, it retains its smoothness and cleanness indefinitely without the rub- bing and polishing required by ordinary metal work, nickel plated or otherwise. The shallow construction of the trap allows it to go easily between the bottom of a bath tub and the floor as shown in Figs. 209 and 367, avoiding the in- conveniences attending traps reaching below the floor. Fig. action about one-half of this water follows the air toward the drain; this amount being - removed, the deflecting- surfaces of that portion of the apparatus thus emptied suffice to rob the air-current of its spray, and under no test that has yet been applied, with an open topped soil pipe, can the seal be broken. The interior of the trap is well exposed to view, and the arrangement for cleaning in of the glass cap to remove an obstruction would be a very small price to pay for the absolute security which Mr. Putnam seems to have achieved. Since the above was written, I have tested Mr. Putnam's trap, finding it effective in withstanding siphonage and substantially self cleansing. It seems to me the best trap that I have seen. This trap or something like it may probably come into univer- sal use for washstands, baths, and laundry tubs — for urinals also where separate urinals are used." Further on in the same article Col. Waring says: "Not only as confirming my own view, but as an illustration of very thorough and careful experimental work, attention may properly be called to an investigation carried on for the City Board of Health of Boston by J. Pickering Putnam, Esq., an architect of that city. These investigations have been set forth quite fully in illustrated communications to the 'American Architect,' which papers certainly mark a very important step for- ward in sanitary literature. The deductions to be drawn from these investigations are these," etc. From the "Century Magazine" for December, 1884. Wm. E. Hoyt. C. E., S. B., Chief Engineer of the B. R. & P. R. R. Co. and at one time Chief Engineer of the Massachusetts Board of Health, says of the trap and other appliances in an address de- livered at the annual meeting of the Academy of Sciences in Roches- ter, N. Y., January. ISSfi: "I have briefly sketched, in one place, the methods of these scientific investigators. You have seen how patiently and cautiously Mr. Putnam has worked in the develop- ment of his Sanitas trap; how, step by step, he advanced, applying all the time scientific principles in the various successive changes of form, which resulted finally in the complete attainment of the object he had in view. The other ingenious appliances for which we are indebted to Mr. Putnam are all of equal merit. I know of nothing to compare with them in convenience, efficiency and safety. They should be regarded in the same light as valuable discoveries in medical science. By the use of these devices we are able to avoid, in a great measure the evils resulting ordinarily from bad plumbing." The "Sanitary Record" of London writes of the Sanitas trap on Sept. 15, 1885: "Mr. Putnam, an architect of Boston, undertook, 226 Seal Retaining Traps. 236 shows its appearance beneath a basin, and Fig. 367 in a modern bath room. Diagram Fig. 231 shows the strength of the "Securitas" trap in resisting siphonage as compared with other traps. The record of the eight traps given first in this table is taken from that obtained for the City Board of Health, except that in this table the loss of water at each siphoning strain is given in percentages of the whole seal. The fig- ures under each trap show the number of siphoning strains or tank discharges applied without refilling. The perform- ance of the "Securitas" trap is a record taken under a siphonage strain of 20 inches of vacuum on a pneumatic some time ago, an extended series of experiments with traps, in behalf of the City Board of Health of Boston. These investiga- tions were published and illustrated in the 'American Architect' at the time, and led to the development of the remarkable trap which Mr. Putnam has called the 'Sanitas.' This trap has gained the unqualified approval of many of the leading engineers of America. "In February of this year Mr. Putnam lectured before the Suffolk District Medical Society, on the 'Principles of Sanitary Plumbing,' and he exhibited before a large audience an exhaustive series of experiments with various apparatus. The same journal, in a later issue, publishes a letter of D. J. Ebbets, in which he writes: "Now there are several traps that may safely be used to defy the severest siphonage encountered in actual practice, but only one of these can claim to be self-cleansing — namely. Mr. Putnam's Sanitas trap. This trap is extensively used in America. It is the best example that we have at present of an anti- siplnmic Trap. "In America, where, partly on account of the severity of the winters it is usual to fix the soil-pipes internally, and to connect all waste-pipes with the soil-pipes, it becomes generally necessary to ventilate the ordinary S-trap, introducing a complication which is very bewildering to the ordinary plumber, and the adoption of whirh entails a considerable addition to the cost of the plumbing work. Besides this complication and expense, there are certain evils which are inseparable from such ventilation; so that in America, at any rate, where self-cleansing antisiphonic traps are to be ob- tained, it would appear to be rather unwise to continue the use of ventilated S-traps." Mr. Walter S. Pardee, Supervising Architect of the Board of Education of Minneapolis, Minn., writes of the trap that it "stands well here, I am glad to say. and the law was changed last fall to permit its u^e (unvented) where back ventilation is not desired," etc. Other cities have done the same. Mr. Pardee adds: "To tell the truth about the matter, I was led to inspect your trap more closely than I would otherwise have done, from the fact that it appeared to be the result of philosophical inquiry rather than of mere guess work. To quote further laudatory remarks in favor of the writer's appliances would seem to savor somewhat too much of a dealer's trade advertisement, and the above will therefore be assumed to be sufficient for our purpose of providing a little outside unbiased testimony to corroborate the writer's descriptions and contentions. 227 S S3 5? Seal Retaining Traps. testing apparatus. The other traps were subjected to about 15 inches of vacuum on a hydraulic apparatus. The Securitas trap was not tested at the same time with the rest, as it was not invented at that time. Later tests on all these and other traps show substantially the same results. Fig. 232 shows the same strains on the Securitas by a different form of diagram. Fig. 233. Fi S- -33a. As shown in Fig. 233a the water makes only a single revolution in passing through the refilling chamber. In Fig. 233 a deep seal is used, not for any advantage to the traps, but because a deep seal is sometimes called for in plumbing laws through the mistaken idea that a deep seal is needed for efficiency. Figs. 234 and 235 show the appearance of the trap con- structed of porcelain enameled steel and Figs. 234a and 235a show it in nickel plated brass, the latter being piped for a running or bath tub trap, and the former for a basin. If desired the top cup may be secured to the lower, as shown in Figs. 222 to 224, by an upper nut instead of by the bolts shown in Figs. 233 to 235. A rubber washer under the nut makes a tight joint, and the law 229 Plumbing and Household Sanitation. which in some places requires all such joints to be under water is in the light of modern science clearly unjustifiable. Lead caulked bell and spigot joints, which the law allows, are scarcely ever tight after use, whereas steam fitters' joints with paper gaskets are tight against any pressure. Our upper rubber joint is on the same principle, and is, moreover, under water pressure at every discharge of the fixture which constantly verifies its tightness. Porcelain enameling on steel has now been carried to a very high degree of perfection as illustrated by its great durability in cooking utensils, where it has to stand the test of the roughest usage, even holding boiling water on a red-hot stove. The usage is not so severe in plumbing. Very rough usage will, of course, crack the enamel. But equally rough usage will destroy the appearance of any ornamented construction. Porcelain enamel is not new in plumbing, its use in bath tubs, basins and closets having long been successful. It is only new in traps, and with this improvement the entire bath room outfit, including walls, fixtures, traps and piping may be constructed, harmoniously, of white enamel, giving an effect of very great beauty. Fig\ 237. Fig. 237 shows four fixtures constructed and set with the simple piping we have advocated. The simplicity of this arrangement is to be compared with the compli- cation shown in Fig. 262, page 266, which is reproduced from a drawing by Mr. Hoyt to illustrate his interest- ing article on safe plumbing published in 1888 in the "Popular Science Monthly." The same four fixtures are provided in both cases but the cost of the compli- cated arrangement is more than double that of the sim- ple one. In the former there are 71 joints and in the latter only 14. In the former bell and spigot hand caulked lead joints are used. The strains on the hubs 230 Fig. 234. Fig. 234a. M ■*-•* L_ Fis: ?35. 231 Iff. 235a. Plumbing and Household Sanitation. Fig 236. Rearranged from Catalog by Courtesy of Federal Huber Co. made by the caulking hammer and the rigidity of the joint require here* the use of extra heavy piping. Whereas the flexible joints used in the simpler system allow of the use of "standard" weight piping with en- tire safety. This constitutes still another important item of economy. 232 CHAPTER XIV. The Two Plumbing Systems. T HERE are, as I have already indicated, two schools or sys- tems of plumbing which may be characterized as the "com- plex" system shown in Fig. 32, and the "simple system" of Fig. 33, the first involving two or three times as much elaboration and expense as the second, and rendering it al- most impossible for the pros- pective purchaser of a house to determine whether it is safe- ly plumbed or not. We have already explained some of the reasons why the simpler system is the best. A public sewer becomes very well ventilated and practically safe when its ventilation is effected by making every, house drain and soil pipe a ventilating flue. The sewer then has, in cities, in addition to the usual public ventilating openings on the streets and elsewhere, also special 4-inch suction tubes every ten or fifteen feet throughout its entire length, assuming the houses on both sides of the street to average between 20 and 30 feet in width each. The temperature in the houses is at all times either warmer, as in winter, or colder, as in hot days in summer, than the air of the street and of the sewer, and thus cre- ates a constant and thorough sewer ventilation. We have 233 Plumbing and Household Sanitation. shown somewhat exhaustively that if disease germs are brought into our houses in air currents, they come in the air outside of the sewers, either above or below ground, and not in the sewer air itself, and we know that whatever putrescible matter, excepting street washings, is to be found in the sewers, comes from the house drains them- selves. Assuming, then, that the houses average say 26 feet wide and 50 feet high, the number of running feet of soil and drain pipe in each would average at best not less than 100 feet, and the interior surface of this house drain pipe being of iron and not so well scoured as the glazed inner surfaces of the sewer, would therefore contain more decomposing matter than that part of the sewer in the street which serves each separate house. It would be absurd, therefore, to insert a disconnecting trap and double or treble the amount of piping in a house for the mere purpose of excluding this extra drain pipe air, even if it were not demonstrated that this very complication increased rather than diminished the chances of its entrance. More than half of this complication is due to the absolutely and at all times worse than useless so-called "back vent" system, a system founded on misconception and perpetuated by ig- norance, prejudice and humbug. Indeed, so far as the sci- ence of plumbing is concerned, this system is already a back number, for the leading authorities in plumbing and sani- tary engineering have placed themselves squarely in oppo- sition to it. Of course it will be useless to study the various plumbing fixtures of a house and the proper methods of connecting them up with the piping until we know what that piping is to be, and accordingly our first duty is to tackle this "back vent" monster and destroy it, for being a thirsty creature, it will, if left on guard over us, be certain in time to lick the water seal out of our traps, or else, by gorging 234 Hydraulics and Pneumatics. itself with grease, to lose all consciousness and abandon the trap seal altogether to its enemies. Like the cholera germ, this most pernicious infliction can- not stand light. The science of hydraulics and pneumatics is fatal to it and shall form for it our club of extermination. The Hydraulics and Pneumatics of Plumbing. The agencies which tend to destroy the water seal of traps are siphonage, evaporation, back pressure, capillary action, leakage and accumulation of sediment. Fig. 233. Diagram to illustrate the phenomenon of siphonage. Siphonage. Our next drawing illustrates the principle of siphonage. A trap consists of a U-shaped bend in a pipe forming an inverted siphon, as shown on the left-hand side of Fig. 238. By filling this trap with water and turning it upside down we see that there is no greater weight of water in one leg than in the other, and therefore there is no tendency on the part of the water to run from one end of the tube or siphon more than from the other so long as the two legs are of the same length. They both pull down from the top with equal force and tend to form a vacuum in the bend. But if we lengthen one leg so that the water in it becomes heavier than that in the other, it will run out, while atmospheric pressure will force the water in the short leg up to the top and out of the tube, because though 235 Plumbing and Household Sanitation. the atmospheric pressure at the bottom of the long tube is very slightly greater than that at the bottom of the short tube, the air column being a few inches longer, this extra pressure of air counts as nothing against the weight of the same number of inches of water column. Now, if the shorter leg of the siphon be dipped in a vessel of water, as shown in the illustration, the atmospheric pressure which before acted on the bottom of the water in the short leg is transferred to the surface of the water in the vessel and will act in emptying it down to the bottom of the short leg and illustrate the well known action of siphoning. The water in the vessel and in the short arm of the siphon constitutes a trap. The long arm is the outlet arm of the trap, and when water from the basin or any other fixture to which the trap is attached flows through the trap and down the long arm, it sets up this siphoning action, which will continue until the trap seal is reduced to a point slightly below the bottom of the short arm of the siphon, or so-called "upcast limb," of the trap, thereby breaking the seal. Frequently a sufficient amount of water trickles down from the fixture and sides of the pipe above the trap after the siphoning action to partially restore the seal. This direct action of the water of a fixture in breaking its own trap seal by si- phoning is called "self-siphonage." A more common form of siphonage, however, is illus- trated in Fig. 239, where the seal of the trap is broken by the discharge of some fixture other than the one to which it is attached, and usually in a story above it. Here the discharge of a water closet in the upper story destroyed the trap seal below ; the falling column of water from the upper closet rarified the air in the soil pipe behind it as it went. To fill this partial vacuum following the water plug air tended to press into the soil pipe through every opening. The friction of the rough sides of a tall stack 236 The Two Plumbing Systems. of soil pipe, even though it be open at the roof, will often cause more resistance to air in its attempt to fill this partial vacuum than will the inertia of the water in any fixture trap below. In the case shown by the picture the outer air found a much easier access to the interior of the soil pipe through the trap seals than by any other way, Fig. 239. Trap Siphoning.* and so it broke these seals and thus opened a free entrance to soil pipe air into the house. The seal of the upper closet would be emptied by the same action. ♦From "Dangers to Health. A Pictorial Guide to Domestic Sanitary Defects," by T. Pridgin Teale, M. A. Pub. by J. J. Churchill, London. 237 Plumbing and Household Sanitation. On the left hand side we see the action of siphonage on a lavatory trap caused by the discharge of a bath tub above. Pig. 240. Diagram to Illustrate Back Venting. (From Bayles.) Three Methods of Protecting Trap Seals. Three methods have been employed with a view to pre- venting the destruction of the seal by siphonage. The most 238 The Two Plumbing Systems. natural method and the one which has been used now for about a quarter of a century is to ventilate each trap by connecting it with a special ventilating pipe constructed for the purpose. Mr. James C. Bayles describes this method in 1878 in his ''House Drainage and Water Service," as one would de- scribe a method at that time not long established, using a cut which I have reproduced here (Fig. 240). It is, how- ever, now generally admitted that the vent pipe shown by Bayles in the cut could not afford even a temporary pro- tection on account of its small size. Incidentally it may be said that Mr. Bayles rightly ob- jects to the use of a main house trap, saying that in his judgment such a trap does vastly more harm than good. Among other reasons he gives for this is that it hinders the ventilation of the sewer. "When the pressure upon the air confined in the sewer," he says, "is increased from any cause, it should have an outflow through every house drain. When from any cause a partial vacuum is created in the sewer, every house drain should be an inlet for air. In other words, we should allow the sewers to breathe through the main waste pipe of every house, besides giving them as many breathing holes in addition as can be provided." The waste piping of houses can now be done without dif- ficulty so as to secure permanently tight work. The second method of guarding against the loss of seal by siphonage is to make the body of the trap so large that a sufficient quantity of water will always adhere to its sides after siphoning to restore a seal. This is the principle of the pot or cesspool trap. The third method is to construct the trap of such a form as to render it both antisiphonic and self cleaning at the same time. The first method adds enormously to the cost and com- 239 Plumbing and Household Sanitation. plication of the work and gives rise to greater dangers than those it was designed to cure. Nevertheless it has be- come popular with many, and is responsible for the so-called "trap-vent" law, once excusable because nothing better was for some time known, but now worse than absolutely in- defensible in the light of our present knowledge, as inviting the entrance into our homes of sewer-gas, now that simple methods are known for keeping it out. In regard to the practical working of trap back venting two things have been made clear. First, that it is not always efficient in preventing siphonage even when new, and very frequently fails when old. And, second, that it is always more or less active in destroying the trap seal through evaporation. The second method is both inexpensive and simple, and is much more efficient and reliable in resisting siphoning ac- tion than the first. It has, however, the serious disad- vantage of involving the use of cesspools or centres of putre- factive decomposition in the house, and brings, in the ag- gregate, a vast amount of pollution into the public sewers tending to frustrate our best efforts in the direction of their complete purification. They are also liable to be converted by grease accumulation into ordinary S or siphoning traps and thus entirely lose their original power of protection. The third method is the simplest and least expensive of all, and has demonstrated itself to be perfectly reliable and satisfactory. Nothing but ignorance and selfish private in- terest has stood in the way of its exclusive adoption. Let us now examine these three methods carefully in de- tail since the question is not only one of the most important and interesting ones in the whole domain of sanitary plumb- ing, but its investigation will throw light upon every other part of our subject. 240 CHAPTER XV. Trap Testing Apparatus. Siphonage and Back Pressure. P HE trap vent pipe was, as * I have said, originally sup- posed to afford a reliable cure for siphonage, and un- der that supposition the trap-vent law was made, and is in operation in the majority of cities and towns which have any plumbing laws at all. For the purpose of test- ing the efficiency of the trap vent when it is new and clean, and therefore at its best, Mr. Hubbard has had the apparatus erected which you see in Fig. 241. The cut shows you the en- tire apparatus, including the parts not visible in the room. On the floor of the attic space above this lecture hall is our large supply tank, having a capacity up to the overflow of 40 gallons of water. From the bottom of this tank descends a 2-inch iron and glass pipe with two branches at a height of three feet from the floor for taking the traps to be tested. The piece of 241 Fig. 241. Apparatus for Trap Testing- Erected at the North End Union for this Course of Lectures. Plumbing and Household Sanitation. glass pipe is 4 feet long and has been inserted in order to enable you to follow the course of the water and study the manner in which air mixes with it in its descent from the tank under varying conditions of the tank valve vent. The valve in the tank is a 2-inch standpipe valve, and the top part of the 2-inch waste from the tank is vented by an inch pipe, descending to within five feet of the floor and, for the present, corked up at the lower end. Below the trap branches is a throttle valve by means of which we shall be able to illustrate the effect of "back pressure," as will hereafter be explained. Below the floor of this hall the 2-inch waste passes through the room below and dis- charges into a 25-gallon tank below the floor, as shown. The tank empties through a 3-inch pipe, which connects with the soil pipe at the basement floor, being trapped on its way with a 3-inch running trap. Now we may suppose that our tank represents a bath tub and the 2-inch iron pipe its waste, and that in the story below two basin wastes enter this waste through the two trap branches which you see, and that our traps are intended to serve these two fixtures. So far we have con- ditions corresponding to those in actual practice with new work where the rooms are very high. The siphoning action may, however, if we wish, be made considerably more severe than is found in ordinary prac- tice by corking up the top of this standpipe valve of our tank, which corresponds with the standpipe outlet valve of a bath tub, and also corking up the vent pipe coming from the top of the 2-inch tank waste, so that no air can enter the waste except through the fixture traps to be tested. Though in practice it often happens that house owners will close up the overflow outlets of their fixtures in the fear of "sewer gas" with corks and putty ; and snow and frost will frequently close up the vent opening. 242 Trap Testing Apparatus. In order to represent "back-vent" piping we have here also some speaking tubing and bends, which we shall apply to the crowns of the traps to be tested and by this means investigate the effect of friction in retarding the action of this back airing. By means of this apparatus we shall be able to determine (i) whether or not seals of traps in common use can be broken even when newly and fully vented and in accord- ance with the law, under conditions which can be and frequently are encountered in plumbing practice; (2) what effect corrosion, incrustation and various forms of clog- ging in the pipes have upon the traps seals; (3) the relative power of various forms of traps in resisting siphonage, and (4) whether any form is capable of resisting the severest possible siphoning action that can be encountered in plumb- ing practice. Before, however, making our experiments with this ap- paratus, which will require light in the lecture room, we will complete our lantern slide work, comparing our plant with those used in my previous experiments for the Boston City Board of Health and at the Massachusetts Institute of Technology and elsewhere, pictures of which will be shown on the next two slides. This cut (Fig. 242) shows the Board of Health ap- paratus. It is composed of ordinary piping erected exactly as it is in regular practice in house plumbing. A vertical stack of 4-inch soil pipe was erected without bends from the outlet above the roof to the horizontal run under the basement floor, a distance of 70 feet 9 inches. The soil pipe was run up straight in this manner in order to furnish the conditions for the severest possible tests for siphonage and back pressure. At the same time it formed the arrange- ment most commonly met with in practice. The unbroken fall of the water through such a pipe evidently creates the 243 Fig 242. Apparatus Used in the Experiments Made by the Author for the Boston City Board of Health. 244 Trap Testing Apparatus. most powerful compression of the air in advance of it and the greatest rarification behind it. Just below the fourth floor was placed a large cistern 44 inches long by 16 inches wide and 15 inches high up to the overflow, inside measure ; or of 46 gallons capacity, as against 40 gallons capacity, which we have here. The cistern served to illustrate the action of a bath tub, by having a i^-inch discharge pipe at its bottom trapped with a Bower's large sized trap, and entering the soil pipe just above the entrance of the water-closet waste. The water-closet used was a plunger closet, at that time popu- lar. To expedite its filling a large service pipe from the cistern was used, and the water was allowed to fill the closet through a brass compression-cock. The water- closet was supplied with a regular overflow pipe so that, when full, its capacity was always the same, i. e., 4^ gal- lons. The plunger of this closet having no overflow, its operation produced as powerful a siphoning action as is possible with any plumbing fixture, and indeed the use of plunger closets is partly for this reason gradually dimin- ishing everywhere. To test the effect on traps below of emptying the tank after the manner of a flush tank, a 4-inch outlet valve and waste pipe were fitted up in the manner shown. Outlets were left on each story below the water-closet for testing the traps at various heights on the stack. The soil pipe was ventilated at the too full size, and had the usual foot vent. Back pressure was generated by the bend just below the basement floor. In order to permit also of a series of experiments on evaporation a 4-inch galvanized iron flue was erected by the side of the soil pipe. This flue terminated just below the first floor in a galvanized iron lantern, with a glass door on its front side. A i>4-inch rubber tube was con- nected with the bottom of the lantern, and an anemometer 245 Plumbing and Household Sanitation. was placed above the point of connection in an enlarge- ment made to receive it. The anemometer was so ar- ranged and placed that it could measure accurately the current of air passing through the rubber tube in either direction. The galvanized iron flue could be tested either cold or heated by gas-jets, as shown in the drawing. A second lantern was placed on the third floor with a similar appliance for heating the flue. A 13/2-inch lead waste-pipe was connected with the soil- pipe just above the basement floor. This branch waste had a number of ventilating openings made upon it, and a deep seal S trap at its end. The trap had three venti- lating openings in its outlet arm, one at the crown and the others below the crown, as shown. All the vent open- ings both on the trap and on the branch waste were pro- vided with small connecting tubes, so arranged that the rubber ventilating flue could be readily attached to either. The openings were, furthermore, all provided with closely fitting corks so that they could be hermetically sealed. By this arrangement the effect of ventilation at different points of the trap or its waste-pipe upon its water seal could be accurately tested. Further tests in evaporation were made by connecting a second branch waste below the first with a brick flue heated by a stove. In order to make an accurate record of these experi- ments the diagrams shown in Fig. 244 were made. In these the trap seal is represented by a vertical line between two circles. The upper circle represents the outlet arm of the trap in section, and the lower circle the inlet arm. The horizontal lines show the level of the seal after each dis- charge. The small diagram (Fig. 243) illustrates a simpler form of apparatus upon which I made a large number of ex- periments on siphonage. I assumed that as severe a test 246 Trap Testing Apparatus. for siphonage to which a trap could be subjected in practice would be that which would be sufficient to siphon out an 8-inch pot trap or a .ventilated S-trap constructed in the usual manner. Such a test may be made by connecting the trap with a 2-inch waste-pipe from a large bath tub, emptied through an outlet large enough to fill the waste-pipe full- bore, the waste plug being successively raised and lowered Fig. 243. Simple Apparatus for Trap Testing. a number of times while the water is escaping. The siphon- ing action produced on a i>4-inch branch connected with such a waste at a point six feet below the tub is sufficient to destroy in one second the seal of a i^-inch S-trap of the ordinary construction, having a vent opening at the crown, of the same size with the base of the trap (ij4 247 Plumbing and Household Sanitation. | 3J o © a 7UVMZ win I TTT Q|Jg , | Q *fc*Wlt it^^u; 248 Trap Testing Apparatus. inches), and connected with a 1 34-inch ventilating pipe of smooth, new lead, sixteen feet long. It will also destroy the seal of an ordinary S-trap having a vent opening at the crown 24 mcn m diameter, without any vent-pipe attached thereto, and will siphon out a pot trap 8 inches in diameter having a seal four inches deep. The tank in this little apparatus, which in principle re- sembles ours here, had a capacity of ioo gallons. The waste-pipe was 2 inches in inside diameter like ours, but only 6 feet long to the trap branch, while ours is 17 feet long to the testing branches. The outlet plug, like ours, was large enough to fill the waste-pipe full-bore. The next figures (245 to 249) give the sections of some of the traps tested, the horizontal lines corresponding with those in the diagrams. Each test was repeated a number of times, the results being each time almost absolutely identical. A single discharge of 15 gallons destroyed the seal of a 1 34 -inch S-trap vented with a i34 -inch pipe 25 feet long, attached at the crown. With this vent-pipe shortened to 15 feet two discharges of 15 gallons each broke the seal. Shortened to 9 feet 7 discharges broke the seal. In the pot traps tests 15 gallons were used at each dis- charge. They all lost their seals, as shown, except the 8-inch pot, tested in the later experiments for the Board of Health, to be described in another chapter, which lost all but a quarter of an inch of its 334-inch deep seal after the tank had been emptied 16 times. The 6-inch pot required four and the 4-inch pot two tanks full to break their seal. On the Board of Health apparatus, also several other traps were tested at the same time with the pot traps, but as only two were able to preserve their seals against the tests applied, and as most of them had already been tested in the experiments made for the National Board of Health 249 Plumbing and Household Sanitation. and their tests published, by which their power of resist- ance as compared with that of a ventilated S-trap and to a pot trap, was made known, it was thought unnecessary to record the failures again in our tests. Fig. 245. S Trap. Fig. 246. 2 in. Pot. Fig. 247. 2% in. Pot. Fig. 248. 3% in. Pot. Fig. 249. 8 in. Pot. Tests for Siphonage on Traps of Different Sizes. The tests for siphonage were made on pot traps unventi- lated and on ventilated S-traps, the traps being placed on the Y branch outlet on the second floor at a distance of about ii feet below the bottom of the water-closet trap, since at this point the siphonage proved to be most severe. 250 Trap Testing Apparatus. The tests were made with the closet alone, and also with the closet and bath-tub combined. The result of the experiments was that the discharge of the water-closet was sufficient to unseal the S-trap even though it was ventilated at or below the crown in the manner prescribed by the plumbing regulations with vent pipes of the full size of the trap. It made no material dif- ference as to siphonage whether the vent-pipe be applied immediately at the crown or at a considerable distance below it. Had the pipes been partially clogged by sediment or rust the results would, of course, have been even more serious. An unventilated S-trap was, of course, completely siphoned out by a single discharge of the closet, leaving only a few drops of water in the bottom of the bend. A 1 34 -inch S-trap having a I % -inch vent hole in the crown and a 1 34 -inch pipe of smooth clean lead 17 feet long attached to the opening, had its seal broken in three discharges. A 13^-inch S-trap with 1 34 -inch vent, constructed as shown in the slide, and having 7 feet of i-inch pipe at- tached to one of the vent openings, the others being closed, lost its seal after 5 discharges. With a 17-foot vent-pipe 4 discharges sufficed. When the bath-tub discharge was added to that of the water closet a single discharge broke the seal with the 17-foot vent-pipe and swept nearly all the water out of the trap. Experiments on the Pot Traps. The pot traps tested on these occasions measured re- spectively 2 inches, 2 l / 2 inches, 3 inches, 3^ inches, 4 inches, 5 inches, 6 inches and 8 inches in diameter, and from these tests we found that their power of resistance to siphon- ing depends upon their size, and more particularly upon the diameter of the body, a half-inch excess of diameter 251 Ptttmbing and Household Sanitation. affording a very considerable excess in depth of seal. With equal depth the resistance will be in direct proportion to the diameter. The 2-inch pot lost its seal in one discharge of the water closet, a 23^-inch pot in two discharges, a 3-inch in four discharges, a 33/2-inch in seven discharges, a 4-inch in seven discharges, a 5-inch in 22 discharges, a 6-inch in 27 discharges and an 8-inch lost i l / 2 inches of its seal in 24 discharges, and would probably have resisted for several hundred discharges. In well arranged plumbing, however, a pot trap having a body 8 inches in diameter and having 1 3/2-inch or i^-inch connections, may be considered perfectly safe so far as retaining its seal is concerned, so long as its seal is not contracted by deposits. An examination of the sectional drawings of all the traps will show at a glance the effect of each discharge on its water seal, the horizontal lines giving the exact level of the water after each discharge. The next figure (250) shows the apparatus erected at the Massachusetts Institute of Technology already referred to.* It consisted of a stack of four-inch soil-pipe with two water- closets set ten feet above the wastes of the traps to be tested. The closets were a Zane and a Jennings, both quite popular at the time these experiments were made. The soil-pipe had a number of bends to exemplify the bends, *Mr. Wm. E. Hoyt, C. E., writes of these tests as follows: "A few weeks ago I visited a mechanical laboratory, where, for over two j'ears, a series of experiments has been conducted on household sanitation. Neither time nor money has been spared to make these experiments and investigations thorough and complete. Here, several skilful sanitarians have been diligently at work in all this time to improve our system of house drainage. One of these men is well known in Europe, as wen as this country, by his scientific investigations and his writings. Let us see what they have been doing. Time will allow a reference to one or two things only. "These men wished to know just how traps and ventilation pipes and other contrivances really worked, under all possible conditions, in houses fitted with modern appliance^, and to ascertain this, they bought a lot of full sized drain-pipes and ventilation-pipes and traps and water closets, and set them up in their laboratory ,1u«t ; r\ the way thev are put into nur lT"Hi c ec. exe^t thnt the^ ^co^n- mized space, as I shall show you by a drawing. (Diagram C.) Fig. 250. 252 Trap Testing Apparatus. more or less of which are usually required in any tall building. The vent-pipes are on the right and were of 2- inch cast iron pipe, also with bends. Openings were left in both stacks of pipe, as shown in the drawing, to permit of a great variety of experiments with long and short piping, and with from only i up to 8 on the soil-pipe stack, and from I to 13 on the trap-vent stack. In this way the apparatus was made to correspond with that in any form of house we desire to imitate. Some of the tests were very severe, but no more so than often en- countered in plumbing practice. If we are to be forced by the law to put our clients to the great expense and danger of ventilating every trap, we have the right to demand, first, that the means employed shall actually afford us the se- curity it pretends to, and not fail at the first critical mo- ment ; and second, that no other simpler and better means exist for securing the desired result. We found that the discharge of either or both closets instantly broke the seal of an unvented S-trap whether the soil-pipe were the full length or shortened to half its length by opening the middle plug. When the falling water in the soil-pipe produces the partial vacuum behind it as it descends, if the soil-pipe extension above it is short and closed at its top, the action is at its maximum because With these great testing- machines they showed the City Board of Health of Boston some exceedingly interesting experiments, which proved to that august body that their official ideas about plumbing fixtures were in many respects entirely wrong. The Bos- ton Society of Architects came aiso to see these experiments, and, later, they were shown before the Suffolk District Medical Society of Massachusetts. The fame of these investigators extended soon to Europe; and an earnest request was made by eminent sanitarians in England to allow the result of these investigations to be pub- lished there in the interests of sanitary science. This important work of the laboratory has been under the direction of Mr. J. Pickering Putnam of Boston; and I am sure that his experiments and investigations are the most comprehensive and thorough and valuable that have ever been made on the subiect of household sanitation." William E. Hoyt, C. E.. S. B.. Chief Engineer of the Buffalo. Rochester & Pittsburgh Railway Company, in an address on "Household Sanitation," delivered before the Rochester Academy of Sciences, Jan. 11, 1886. 253 Plumbing and Household Sanitation. there is very little air to expand. If the pipe is short and open at the top it is at its minimum. If it is long and closed still the action is powerful, but if it is long and open above, a medium effect is produced, and this was the con- dition we had in these tests. We next ventilated our S-trap with a vent-pipe the full size of the bore of the trap. Leaving the soil and vent Fig. 250. Apparatus for Trap Testing used at the Massachusetts Institute of Technology. pipes full length, we found three discharges of the two closets was sufficient to destroy the seal. Thus we showed that with the long stack of pipe our ventilation signally failed. We next cut off half the bends and half the length of both soil and vent-pipe, leaving a medium length of 254 Trap Testing Apparatus. each of forty-five feet of new pipe, and we found that four discharges of the two closets destroyed the seal. In the next experiment we broke the seal with two dis- charges using a 1 34 -inch vent pipe, and afterwards broke it with four discharges on shortening the vent to 15 feet. This gave a shorter vent-pipe than we should ever be likely to encounter in practice. Hence if the friction produced in this short length of pipe is enough to prevent the effect- iveness of the vent, anything longer than this would have destroyed it still easier. This shows that our expensive venting is utterly untrustworthy. In the Boston Board of Health tests the same results were obtained by the dis- charge of a single plunger closet. The tests were made on a 2-inch by 4-inch Y. In our experiments for the City Board of Health we were severely criticized by 'The Sanitary Engineer" for using a 4-inch by 4-inch Y branch, which we were told, would produce an action at least four times as powerful as the smaller branch. In order to test this point we connected our waste with the 4-inch by 4-inch branch shown immediately below the 4-inch by 2-inch branch and made preparation to re- peat the last test under the new conditions. We cautioned the audience who were seated nearest the trap to hold firmly to their seats, which had been tightly screwed to the floor in order to prevent them from being sucked bodily into the drains by the prodigious siphoning power of the 4- inch by 4-inch branch claimed by "The Sanitary Engineer." On discharging the closets, however, we found no ap- preciable difference in the two Ys, and the gentlemen in the first row were then advised that they could confidently re- lease their hold upon the furniture. When the mouth of the vent-pipe has become partially closed by the gradual deposit of sediment, the supply of air through it is proportionally retarded, and it becomes 255 Plumbing and Household Sanitation. less and less of a safeguard against siphonage. We had made a great many experiments in this field and found the resistance exactly proportioned to the size of the vent-pipe. The stack of pipes shown in Fig. 251 shows a trap vent pipe 125 feet long in a tall apartment house, which in compliance with the building law I was obliged to specify. As you see by the drawing the lavatories are placed over Fig. 251. Trap Vent Pipe 125 ft. long in a tall Apartment House. one another in such a position that the distance from their traps to the main ventilated soil pipe is not over 18 or 20 inches. These short branch wastes were powerfully flushed at each usage of the fixtures by a stream of water filling them "full bore," and discharging at the rate of nearly half a gallon a second. Traps were specified which cannot by any possibility be siphoned out, nor even have their seals 256 Trap Testing Apparatus. /fa4-inch branches to the main vertical waste pipe, also i^-inch in diameter. A pailful of water thrown into the upper hopper siphoned % of an inch out of each of the two lower traps. Another pailful unsealed them. When the air pipe at the top of the main waste pipe was stopped up this discharge of the top sink also siphoned its own trap. Mr. Hellyer then ventilated each trap as shown by the dotted lines, and repeated the tests. This time scarcely a sixteenth of an inch appears to have been drawn out of the lower traps, although the water was vibrated in them. With a trap at F at the bottom of the stack, back pres- sure was so great at the lower sink trap that it forced a spray of water 12 or 18 inches from the trap out into the sink. Fig. 268 shows another arrangement used by Hellyer in his experiments. The perpendicular main waste pipe was here 2 inches in diameter and had three 2-inch branches, the upper for a bath, the middle for a slop-hopper and the lower for a wash basin. The middle branch had also several different sized traps on it. When the traps were not ventilated each of them could be unsealed by the discharge of the bath tub. Indeed all four of the lower small traps were unsealed at once, but these ventilated the large trap on the middle branch and protected it partially. But it also lost an inch of its seal. When the traps were ventilated, as shown by the dotted lines, only one trap lost any water. This was the trap U, which lost l A of an inch. * "Lectures on the Science and Art of Sanitary Plumbing," London, 1882. 272 Fig. 269. 273 Plumbing and Household Sanitation. (7) Had he known the inevitable consequence of the law in introducing unintentional defects and by-passes, mistakes which have alone vastly more than offset any possible ad- vantages back venting could provide. Mr. Hellyer would have found several other very serious objections to trap venting which I have referred to in other places. Mr. Hellyer's conclusions and recommendations resulting from these experiments were that every trap should be "back vented," and it is probable that this hasty conclusion and the wide circulation his publications enjoyed are largely responsible for the tremendous mistake of the trap vent law, a mistake which, regarded from the standpoint of pecuniary loss alone, has already cost the public hundreds of millions of dollars. Mr. Hellyer would have found his vent pipes would have failed to protect the trap seals under any of the following conditions : ( 1 ) Had the vent pipes been partially reduced in area by sediment deposit at the bottom or by frost at the top, or by rust anywhere in its length. (2) Had the overflow pipe of the bath tub been plugged as is very frequently the case. (3) Had the modern siphon jet or other closets having a strong and rapid flush been used in the tests. (4) Had the vent pipe been very long and rough or contained an unusually large number of sharp bends. (5) Had the experiments been prolonged sufficiently to try the effect of evaporation in the trap seals produced by the ventilating current. (6) Had he investigated capillary action. 274 Fig. 271. Author's Pneumatic Trap Testing Apparatus. 275 Plumbing and Household Sanitation. It must be borne in mind that the value of our tests lies in showing not only the absolute but also the rela- tive power of resistance of unventilated anti-siphon traps and the ventilated S trap. In making a comparison it would not be sufficient nor conclusive to show that unventilated anti-siphon traps are as efficient as the vented S under certain moderate strains. Their value can only be fully demonstrated when it is shown that they are superior to the vented S, not only under moderate but under every possible condition that can be encountered, and even under strains greater than are met with in ordinary prac- tice, and clearly the larger the range of tests the more con- clusive the comparison. We should be justly open to criti- cism if, in making our tests we stopped anywhere short of a thoroughly comprehensive and exhaustive comparison of all forms of traps under every form of strain, from the mildest to the severest which could be applied. We have found that a single discharge of about four gal- lons from our tank was able to break the seal of our i%- inch S trap with a 1*4 -inch clean new vent pipe only 6 feet long and having upon it a single return bend. And we found that the same trap could be siphoned out by two such discharges with a 6-foot vent pipe roughened on the interior surface as by rust even without any bend at all on the pipe. This test was made with the air pipe under the tank valve closed as by sediment or frost. Our air pipe takes the place of a ventilated trap under a bath tub, to which our tank corresponds. The overflow to the tank was closed as is sometimes done with the overflow pipe of bath tubs. We then tested the vented S, with the air pipe open, and found that its seal could be broken by two discharges of four gallons each, the length of the trap vent pipe being 18 feet and having two return bends. Now it is not necessary for us to show whether or not this strain was more severe than was ever possible in 276 Plumbing and Household Sanitation. plumbing practice, because our chief purpose then was to compare the vented S with other traps unvented, and we found in our experiments that our 5-inch pot trap was able to withstand without loss of seal more than a dozen discharges made under precisely the same conditions as were applied to the vented S, including the very severest. The superiority of the large sizes of our unvented pot traps over the vented S in the matter of resistance to Fig. 273. siphonage was, therefore, absolutely demonstrated under conditions in which the whole apparatus was comparatively new. Our contention is, then, that an unvented pot trap of large size is safer as a protection against siphonage than a vented S, and that the former will retain its power of resistance to siphonage longer than the vented S. In places where grease or other sediment is liable to collect 278 Trap Testing Apparatus. in the scouring waterway of traps, it is still more liable to collect in the unscoured mouth of the vent pipe, and the pot trap cannot be clogged by frost, whereas the vent pipe can and often is so closed. In every other respect the superiority of the unvented anti-siphon trap system over the vented S system is too evident to need further discussion. Each state board of health should be equipped with some simple form of testing apparatus like that shown in Fig. 271 or like the pneumatic apparatus recently devised by the writer and shown in Figs. 272, 273 and 273a. They may be made by any plumber or coppersmith with- out difficulty in a few days. A very considerable economy can be realized if several duplicates of the apparatus are made -at the same time. In all the demonstrations in siphonage of which I am aware up to the present time, the tests have been made by hydraulic apparatus, such as have been herein exempli- fied. But of late I have found that a pneumatic apparatus permits of a much greater accuracy of determination, espe- cially in making comparative tests. By using a suction pump, as shown in Figs. 271, 2.^2 and 273, we are able to reproduce at will any degree of rarification in the soil pipe desired to correspond with the varying conditions encountered in plumbing practice, as well as strains far beyond the usual ones for the purpose of comparing dif- ferent traps and systems of plumbing with one another, and a vacuum gauge enables us to apply precisely the same degree of vacuum to every trap tested, so that results of great accuracy and scientific value are obtainable. Of course, it will be objected at first thought that the pneumatic test does not reproduce in actual form the pre- cise phenomena encountered in ordinary plumbing work, but a little reflection will show that the results are identical 279 Plumbing and Household Sanitation. so far as they affect our inquiries. The agency which produces siphonage is the partial vacuum in the soil pipe, and this rarification is effected by the rapid movement of a piston. Whether the piston be in the barrel of a pump or whether it be in the soil pipe itself is altogether im- material so far as concerns the effect of the partial vacuum on trap seals. The pneumatic apparatus possesses the great advantage over the hydraulic of enabling us to vary the force of the strain applied to the traps to any extent de- sired, while only one degree of rarification can be obtained by the falling water plug in any one plant. The siphoning action in both cases is extremely rapid, almost instantaneous. In the case of the falling water piston, the action takes place in the flash of time required for the piston to pass by the small mouth of the branch waste pipe serving the trap. A fraction of a second suffices for this. In the case of the air pump apparatus the speed of the action is measured by the time it takes to move the valve lever connecting this branch waste pipe with the soil pipe. This requires but a fraction of a second, and the speed may be regulated to correspond accurately with the hydraulic action. Moreover, a vacuum gauge may be applied to the soil pipe in both kinds of apparatus and thus the action may be proved to be in both cases identical in speed, power and effect. The duration of the siphoning strain may be increased by increasing the size of the main pipe represent- ing the soil pipe from which the air is to be exhausted. In order, however, to be satisfied as to the similarity of the effect produced on the gauge and trap seals, one has only to have erected side by side apparatus of both kinds, as the writer has done before several audiences, and it will be found that when the vacuum gauge registers the same degree of rarification in both soil pipes, the effect on the traps in each is the same. 280 Trap Testing Apparatus. It is possible on our pneumatic apparatus to produce a strain equal to a vacuum of twenty-six inches, and yet we find the large sizes of drum traps and other anti-siphon traps capable of resisting, unvented, this strain even many times repeated without refilling. The first application of the strain lowers the seal considerably, the second and third less, and thereafter subsequent applications without refill- ing have little effect upon it, and finally a point is reached when no appreciable further reduction can be attained, however often the strain is repeated The vented S trap, on the other hand, is incapable of resisting a vacuum of a single inch when the vent pipe is long and crooked, or when it is partially roughened or closed by deposits. A few inches of vacuum will destroy its seal even when the vent pipe is new and clean and as short and straight as it is possible to make it in practice. The apparatus shown in Figs. 271 to 273 inclusive are easily and cheaply constructed of brass tubing, polished and nickel plated, with a vacuum pump constructed with special accuracy so as to enable it to produce and maintain a vacuum as perfect as is possible. There is, therefore, no excuse for any board of health or plumb- ing inspector's office to be without such a plant, be- cause its use would demonstrate the folly of the trap vent law and save to the citizens, by its repeal, more than the entire cost of the apparatus in a single good-sized building. Fig. 273 is a very small, compact form of portable ap- paratus devised by the writer for lecture service. It meas- ures less than two feet in height and if constructed of alumi- num may be very conveniently transported by hand in a canvas or light leather case. A simple hydraulic apparatus may be constructed and used side by side with the pneumatic outfit where it is 281 Plumbing and Household Sanitation. desired to demonstrate the identity of the results pro- duced by the two systems. But, as before said, the use- fulness of the hydraulic plant is limited to a very narrow range of tests and it is less accurate and comparatively unscientific. It involves, moreover, the consumption of a very large amount of water where the pneumatic plant can be operated without any expense whatever. Fig. 273a. Fig. 273a represents another form of apparatus for lec- ture service. Its action is entirely automatic. A small electric driven pump shown at the lower tank raises the water continuously from this to the upper tank by the elec- tric current taken from an ordinary electric light fixture, through the small pipe shown at the left side of the tanks. When the upper tank if full it discharges automatically, 282 Trap Testing Apparatus. and its discharge operates alternately the valves connecting the traps with the central waste pipe so as to produce upon them the siphoning action, and thus makes simultaneously a comparative as well as an absolute test of any traps de- sired. The central ratchet wheel governs the siphoning and refilling of the traps. The action continues as long as the current is kept on, and the tests are thus made at a minimum of expense with a maximum of convenience. With either of these simple forms of testing apparatus one stands entirely independent of outside testimony as to the relative efficiency of the trap venting and of the anti- siphon systems, and can see for himself in a few minutes the truth in such controversies as have been published, rela- tive to the Worcester tests, for instance. There is no excuse whatever for any doubt in the mat- ter, and no one thereafter would dare to publish any in- accurate or misleading statements in this very important domain, knowing that any board of health or building in- spector's office can authoritatively refute such misstate- ments at once. In order to make the tests of the efficiency of different traps on our pneumatic apparatus, it is neces- sary to first close all the stop cocks shown in the drawings by wheel or lever handles between the traps and the main pipe, and exhaust the air in this pipe by means of the vacuum pump, until the vacuum gauge shows the degree of rarification desired to correspond with what would be encountered in any case of plumbing to be represented. After filling the traps with water, one opens the stop- cock between the trap to be tested and the pipe system, so as to allow air passing through the trap to break the par- tial vacuum therein. This air will follow the path of the least resistance. In the case of the S trap the special air vent pipe is provided between the trap seal and the waste system under the supposition that it will present an easier path for the air than the trap itself, in which the water seal 283 Plumbing and Household Sanitation. might be expected to afford greater resistance to the air passage than the friction of the sides of the vent pipe. The apparatus shows that this is not the case. The ordinary lavatory S trap is shown on the right-hand side of the apparatus vented at the crown with a "back vent" pipe the full size of the bore of the trap, and of consider- able length, but having openings at different points pro- vided with stop valves to show the effect of longer or shorter vent pipes in plumbing work. The longer the vent pipe and the greater the number of bends in it, the greater the obstruction by friction to the passage of the air through it, and the lower its efficiency as a means of protecting the trap seal from siphonage. It is evident, therefore, that the degree of vacuum in the pipe system required to break the seal of a vented S trap is inversely proportional to the length and diameter of the vent pipe, and our apparatus is designed to show the effect of any possible degree of vacuum on any possible length and size of vent pipe, and it will again be seen on this apparatus that the seal of an S trap can be broken by a vacuum con- siderably below that which may be obtained in ordinary plumbing practice, even when the trap has a perfectly clean vent pipe of moderate length, provided a few bends are introduced in running the vent pipe. If the friction is increased by more or less clogging the siphonage is by so much easier. The only weak point in the employment of the ordinary unvented "pot" or "drum" trap of large size as a substitute for the system of back venting is that such a trap is not self-scouring. This weak point is referred to by advocates of back vent- ing as sufficiently important to justify the condemnation of the whole system of unvented trapping, 284 Trap Testing Apparatus. We have explained the fallacy of this argument by show- ing that the vent pipe is still less self -scouring, and that, once clogged, it can not be so easily cleansed. Neverthe- less, it must be admitted that the cesspool element in all reservoir traps is a very undesirable feature, and that not the least of its objections is the fact that it furnishes the opposition with an argument, however inadequate, against the use of the simpler system of plumbing. Moreover, the use of cesspools in a system of house drain- age is contrary to the first principles of sanitary engineer- ing, and an evil which may be of comparatively slight im- portance when confined to the small proportions of a single fixture trap, becomes of very great importance when multi- plied by thousands or hundreds of thousands in the complete drainage system of an entire city or town. It is also perfectly true that the clogging up of the ordi- nary drum trap converts it in time into an S trap, and completely deprives it of its anti-siphon feature. So long as it is allowed to remain clogged, a system based upon the use of such traps loses its efficiency and, however far su- perior it may be to the "back vent" system, it can not yet lay claim to permanent efficiency with automatic action. Hence it is all-important to know if the cesspool element of the common anti-siphon trap can be eliminated and the self-scouring property of the simple S trap or of a straight piece of smooth pipe of equal area can be combined with the anti-siphon quality of the ordinary drum trap. For over a quarter of a century persistent and untiring efforts have been made to attain this combination, until at last it became generally believed that the two requirements were really antagonistic to one another, and that the solu- tion, therefore, was as impossible as the discovery of flexible glass or transparent rubber, a large body of water and a deep seal being assumed to be necessary to withstand siphon- 285 Plumbing and Household Sanitation. age and the exact reverse being needed to produce the maximum of self-scouring effect. It was found that resistance to siphonage increased with the increase of water head in the seal of the trap, and it is sufficiently evident that even in an S trap a seal deep enough to balance the weight of the atmosphere, say 32 feet, would be able to resist any siphoning action which could be brought to bear upon it, since Nature's abhorrence of a vacuum ceases under a water pressure of 32 feet. Accordingly, the idea has prevailed that depth of seal is an essential quality in anti-siphon traps, and nearly all such traps have been and are being constructed on this assumption. It has been clearly shown that this idea is fallacious, and that exactly the reverse is essential to meet all the require- ments of the problem. It does not follow that because a depth of seal of 32 feet is capable of resisting completely siphoning action, there is no other equally efficient manner of accomplishing the same result without the objections attending the perpendic- ular form. These objections are, first, the impossibility in practice of finding sufficient room under a fixture to give an unvented S trap the depth of seal required for adequate protection against the strongest siphonage encountered in plumbing practice. Four or five feet of such seal would be essential in an unvented S trap for entire safety. I have broken the seal of such a trap nearly six feet deep on different forms of apparatus. Secondly, the resistance to the outflow and consequently the lowering of the scouring effect of water through the use of so deep a trap, and, finally, the prohibitive cost of its manufacture and installment. Fortunatelv, there is another method of overcoming siphoning action besides that of opposing direct resistance 286 The Fallacy of Deep Water Seals for Traps. thereto, namely, the diametrically opposite one of reducing the resistance to a minimum. This is accomplished by forming the shallowest possible seal, but constructing the trap in such a manner that the seal shall simply move to one side for a moment and allow the air of siphonage to pass, and then return to its place. It is an application of the principle which gives success to the reed in competition with the oak. It bends to the storm and rises again when its fury has passed, while the oak is shattered by its oppo- sition. Nor does it follow, fortunately, that because a seal is very shallow it must on that account be a correspondingly weak one. As I have shown, a trap may be constructed in such a manner that the shallowest possible seal may have a strength so great as to be absolutely irresistible. A seal a quarter of an inch deep may be made in such a way as to withstand indefinitely the severest test of siphonage, back pressure, evaporation and all other adverse influences to be encountered in plumbing. It will withstand unvented a strain of siphonage powerful enough to destroy the seal of a fully vented S trap or of a drum trap of the largest diameter. In my various experiments on the behavior of different sizes and forms of drum traps when subjected to siphoning action, I have found their resistance to be in direct propor- tion to their diameter rather than to their depth of seal. Indeed, the latter has, within the narrow limits practicable in construction, no appreciable influence whatever. 287 CHAPTER XVI. Self-Siphonage and Momentum. SELF - SIPHONAGE takes place when the waste water flows through the trap "full bore" from the fixtures. As usually constructed, wash basins have outlets far too small in propor- tion to the size of the waste pipe and trap. The strainer cuts off a consid- erable portion of the passageway, and the hairs, lint and other sediment which soon invariably collect on the strainer cut off another large portion, leaving an outlet sometimes not more than equivalent to a y 2 -'mch or ^-inch pipe. The waste pipe and ordinary S trap are usually i^-inch or i*4- m ch in diameter, so that the stream of water admitted to flush and scour them is reduced to less than a quarter or a sixth of their capacity, and we wonder why our trap and waste pipes are never thoroughly scoured. An S trap is no more self- cleaning when the water stream admitted is less than a quarter or a sixth of its capacity than would be an ordinary pot trap having a stream of the same size relatively to itself passing through it. In other words, a i^-inch S trap attached to a ^-inch waste flowing "full bore," or to a waste having a y 2 -'mch inlet, is no more self-scouring than would be a 3-inch pot trap attached to a i-inch waste also flowing full bore, and therefore such an S trap becomes practically then a "cesspool" trap. This is a consideration of great importance, but one which appears generally to be lost sight of, and our plumb- 288 Self-Siphonage and Momentum. ing laws are defective in not recognizing it. It is one of the principal causes of the collection of sediment in branch wastes and ordinary S traps which have a false reputation of being universally self-scouring. They are evidently only so when properly set, and when the waste water from the fixture is permitted to flow through them rapidly and "full bore." It cannot pass rapidly "full bore" unless the outlet and strainer give an open waterway as great or greater than that of the waste pipe and trap. It should be greater in order to allow something for friction and sedi- ment. A trap having a very deep seal retards too much the rapidity and strength of the water current passing through it; hence it should be made as shallow as possible consistent with other requirements. Assuming, now, that we have properly set our trap in such a manner that a rapid stream of water passes through it full bore wherever the fixture is used in a legitimate manner, we shall find that, where an S trap is used, a siphon is formed by the outflowing waste water, which, without ventilation, breaks the seal of the trap. Hence the vent must be placed either at the crown or near enough to it to break the longer leg of the siphon. The momentum of the falling water assists the action of self-siphonage, and it is necessary for perfect protection against these two forces to vent very near the crown. To make a practical test of the truth of this I had a wash basin fitted up with an outlet large enough to fill a i ]/ 2 -inch waste pipe and S trap full bore. Through this outlet the basin was emptied in 2^4 seconds, and the seal of the trap was completely destroyed by the siphonage and momentum of the falling water. The trap was an ordinary cast lead trap, having the usual seal of ij4 inches, and was connected with a waste pipe of the same size with the bore of the trap. With a waste pipe very much larger Plumbing and Household Sanitation. or smaller than the bore of the trap the seal is not so easily broken by self-siphonage, for obvious reasons. Sediment Collection in S Traps Converting Them Into Cesspools. In order to ascertain if the smallness of the outlet of a fixture could actually convert an S trap into a cesspool trap, as I have above asserted, and to study the effect of ventilation in removing deposits from cesspools, I have made a number of experiments on sediment collection and removal. I believe all unprejudiced and well-informed sani- tarians now admit that the special vent pipe is no longer to be recommended as a protection against siphonage, for the reasons I have mentioned. All admit, however, that the main stacks of soil pipe should be thoroughly vented at head and foot. The object of this is to dilute the gases of decomposition to such an extent as to render them as harmless as possible, and then to remove them from the premises. Liberal ventilation hastens somewhat the oxidation of the foul matters in the pipes, but not enough to form an active agent in removing solid impurities. There has been nevertheless a great deal of misunder- standing and idle theorizing on this subject among writers and practitioners in sanitary plumbing. There are advo- cates of indiscriminate venting who profess a preference for air pipes even to a thorough water scour, the most radical ones going so far as to affect for the latter com- parative indifference, saying, "If compelled to choose be- tween oxygen and suds, we should give the former prefer- ence every time."* Let us now, therefore, abandon theories and authorities and seek for facts to guide us in forming an independent judgment on this very important question. The only ques- tion, then, now in dispute is : Do traps and branch waste James C. Baylies in the "Sanitary Engineer." 290 Author's Experiments on Sediment Removal by Air Flushing. pipes require the application of special vent pipes to pre- vent an accumulation within them of solid deposits and corrosive gases? The first experiments were made on solid and the second on gaseous impurities. Under the first heading it was necessary to determine, first, if and to what extent the removal by oxidation of the refuse matters in our waste pipes goes on under a ventilating current under the vary- ing conditions possible in practice ; second, at what rate the accumulation of sediment or solid deposit goes on under the same circumstances ; third, to what extent a water scour is able to prevent and remove solid deposits without the aid of the special vent pipe ; and fourth, to what extent traps and branch waste pipes are self-ventilated without the aid of the special vent pipe in good plumbing practice. The first tests were made as follows : I had pipes evenly coated with deposits found in house- drain pipes and under the conditions met with in ordinary practice, and made, first, a series of extremely delicate and careful experiments to determine the value of air currents in pipes as a scouring agent. The maximum rate of this scouring or cleansing was first ascertained by performing the tests under all those conditions which are found to be most favorable to it. Thus the rate of oxidation is greatest when the ventilating current is most rapid, when the temperature is highest and when the largest surface is exposed to the current. The first experiments were, therefore, performed under these conditions. The waste pipes used were of the diameter of ordinary branch wastes, \ l / 2 inches, and were 6 inches long. They were connected with a heated flue by means of an ordinary i^-inch vent pipe in the manner usual in practice, so that the ventilating current should traverse 291 Plumbing and Household Sanitation. the pipes to be tested from end to end. The time of the year was in midwinter, in January and February. The pipes were uniformly smeared on the inside with substances found in house drains, using in some common soil from a soil pipe, and in others soap solutions found in lavatory wastes. The deposits were first thoroughly dried in the pipes in order to enable them to be accurately weighed in the laboratory, and they were afterwards mois- tened three times a day throughout the tests, about as they would be in ordinary practice. The weight of the deposit in the pipes containing soil was 3.652 grains. That of the lavatory waste was 3.1685 grains. The deposits were then thoroughly moistened with clean water applied with a dropping tube and the pipes connected with the ventilating flue. The velocity of the air current passing through them was then accurately meas- ured and found to be very strong, averaging 8 feet a second, and this velocity was maintained throughout the whole series of tests by means of a stove connected with the main flue, into which the ventilating flue opened. This movement is evidently as rapid as would ever be met with in plumbing practice. The thermometer at the pipe during the tests averaged about 8o° F. Great care was taken throughout to insure that no foreign substance whatever should get into the pipes tested. No dusting or sweeping was allowed in the rooms and only pure water was used to moisten the deposits. An evapora- tion of the water used would show a weight of bacteria and other solid matter too small to be detected by our scales. In short, every precaution was taken to obtain reliable results. After an exposure of a week, under these conditions, to the air current, the pipes were again placed in the air bath for an hour, and the deposits in them thoroughly dried at 292 Author's Experiments on Sediment Removal by Air Flushing. a temperature of 230 F. Upon weighing, it was found that both deposits had gained in weight. The soil had gained 0.4955 grains and the soapy mixture 0.0130 grains. The tests were then repeated under the same conditions for a second week. This time the gain of the soil was re- duced to 0.4775, and the weight of the lavatory waste was increased to 0.0315 grains. The bacteria of decomposition and nitrification had evi- dently not put in their most effective work, and it is prob- able that the conditions as to light and moisture were not favorable for it. So far the air passed through the pipes was pure air from the room. In the next experiments the ordinary air from the house soil pipe was used and its velocity was 7 feet per second. At the end of a week the soil had lost 0.0575 grains and the lavatory matter 0.0352 grains, which was equivalent in the first case to i~70th of the entire weight of the deposit and in the second to i-iooth part. Either of these amounts dissolved in water and spread uniformly over the surface of clean pipes of the size of those used was found to be altogether imperceptible to the eye, and the complete purification of these pipes by ventila- tion under the most favorable circumstances would at this rate require from 70 to 100 weeks, or from i l / 2 to 2 years, supposing there were no addition made to the deposit during the interval through use of the fixture. We then made the tests with the deposits kept dry as might be the case in pipes under fixtures temporarily in disuse, with approximately the same results, and from all the experiments we reached the conclusion that the solid deposits in the interior of soil and drain pipes are removed so slowly by the oxidation produced by ventilation as to be practically valueless. The second point investigated, namely, the rate of accu- 293 Plumbing and Household Sanitation. mulation in pipes of deposits in ordinary plumbing, re- quired no special experiments. We have ample data in our everyday experience in plumbing. Considering, first, the worst conditions, namely, those of the cold waste pipe from the ordinary kitchen or pantry sink, we know that the accumulation of grease in these will be so rapid as to entirely clog up the pipes in a short time where special precautions are not taken to flush out the pipes from time to time with hot water or some solution of caustic alkali, or where sinks constructed on the principle of an automatic flush tank to be hereafter described,are used. So far as the ventilating current is concerned, however, its well known and generally admitted tendency is to congeal the grease and increase the clogging rather than to diminish it. Consider next the case of an ordinary soil pipe. We find that the tenacious soil will adhere stubbornly to the pipe in masses where it strikes until it is washed away by a power- ful fall of water, and that it is not equally distributed in a thin film all over the surface. Parts will be found which are never touched by the waste matter, and parts which are alternately fouled and then scoured clean again. Generally large masses of deposits will be formed in the cavities of the joints or in holes in the castings. In short, the deposits in soil pipes are not slowly distributed favorably for oxida- tion, but are formed in lumps suddenly, and are either as suddenly removed by the flushing water or are deposited in cavities which largely screen them from the influence of the ventilating current, and therefore in this case also the influence of aeration in removing the solid matter is com- paratively very slight. The accumulations of heavy matter will continue in time to increase until they leave an opening only large enough to allow room for the ordinary water flushing stream to pass. Take next the waste pipe from a lavatory. We find the 294 Author's Experiments on Air Flushing. solid deposits here of two kinds, one collecting in clots or masses in corners or unscoured areas, as lumps of soap, hairs, lint, etc., and the other coating the pipes in thin films as of soap-suds. The former are deposited suddenly, and are either swept away by the water or caught in the un- scoured cavities and remain there, partially screened from the air current, until other similar substances accumulate above them. The ventilating current, therefore, can have no appreciable effect in removing these masses of matter. Where, on the other hand, the traps and waste pipes are so constructed and flushed that no such masses can collect, the only kind of deposit that can form in the interval be- tween the flushing will be of the second kind, namely, a thin film of matter like soap-suds, and this the next dis- charge will remove. It remains to be seen what effect a powerful water flush- ing has on these deposits, and this brings us to our third consideration. 295 CHAPTER XVII. Water Flushing. Pt/xfoUd. Fig. 275. Experiments on Water Flushing. N order to obtain a direct comparison of the relative value of a thorough water and of the greatest possible air flushing, the same pipes, tested as already described under the air cur- rent, and containing identically the same deposits, were next tested un- der a good water flush. They were attached to a properly constructed lavatory, as shown in Fig. 275, and cold water was discharged through them in the usual manner. Although the deposits were dry and hard, they were almost entirely washed away after ten discharges. After fifteen discharges the amount of deposit left on both pipes was less than half a grain. When the substances were soft on the application of the test they were removed at once and entirely by a single discharge. From these investigations we have found that the water flushing was infinitely more rapid and thorough in its cleansing power than the air flush. Now there is nothing to prevent every lavatory from being so constructed as to properly flush the waste pipes at each discharge. In fact, there are a great many reasons why it should be looked upon as an absolute necessity in good plumbing. Hence special trap and branch waste vent piping is, for the purpose of removing solid deposits, not only inefficient, but also entirely unnecessary. We come now to the fourth consideration: 296 Water Flushing. Self- Ventilation of Traps and Branch Waste Pipes. But supposing it had been shown that special trap ventila- tion were necessary instead of the reverse, it would still be superfluous to apply the special vent pipe, because the ventilation in proper plumbing is thoroughly accomplished without it, and in several ways. If our main stacks of pipes are open above and below, as they should be, and thus thoroughly aired, the branch wastes will be ventilated in the first place by the well known law of the diffusion of gases. In the second place, a movement of fluids up or down the main stack creates in the branches suction strong enough sometimes even to destroy the seal of ordinary traps. This suction, be it strong or feeble, always produces an interchange of air in the branches. Finally, a third and still more important way in which natural aeration is produced is by the usage of the fixture itself. Every time the water is discharged a column of pure air is drawn from the room into the waste pipe after the water column. Everyone has observed how the air follows the water, and is drawn through it in the form of an inverted cone or funnel, generally with a loud sucking noise. When the fixture is properly constructed, with an outlet large enough to fill the waste pipe "full bore," a column of air equal to the size of the water column is drawn after it, completely filling the waste pipe with pure air from the room. In short, ample air follows every dis- charge to accomplish all that the soil pipe air of the trap vent could do in the interval between the usages of the fixture. The pure air from the room could not possibly be rendered so foul in the interval as the soil pipe air would be, as they are constructed to-day, before it entered. This is equally true whether the fixture be used often or seldom, 297 Plumbing and Household Sanitation. provided it be properly constructed and set, and whether the branch waste be long or short. Thus the special trap vent is superfluous for scouring, not only because the traps may be fully vented without it, but also because a good water flushing accomplishes all and infinitely more than the air could do. Removal of Gaseous Impurities. The chief difference between the main soil pipe and the small branch wastes in relation to venting is that the foul air in the former cannot, and in the latter case can, in good plumbing, be thoroughly changed by flushing and diffusion. Hence, in the main wastes, special venting is necessary to remove gaseous impurities and in the small branch wastes it is not. What has already been said in regard to the capacity for the removal of solid impurities from the smaller waste pipes of a good water flush holds with still greater force in relation to gaseous impurity. The lighter gases are instantly removed by the water stream and replaced by pure air from the room, and this substitution is as much more desirable than the substitution of soil pipe air as the former is richer in oxygen and freer from injurious ele- ments than the latter. Back Pressure. "Back pressure" in plumbing is a force acting in a direc- tion precisely opposite to that of siphonage. It indicates that the air in the drains is under compression, where with siphonage it is under rarification. Hence it tends to force the water of traps from the drains outwards into the house where siphonage tends to force it inwards from the house into the drains. This compression of air in the drains may be caused either by the movement of fluids in the house pipes themselves or by external influences acting 298 Author's Experiments on Back Pressure. upon the air of the sewers, such as the pressure of wind and tide at the sewer openings or a change in the tem- perature or volume of sewage within the pipes. With properly ventilated soil pipes the expansion or contraction of the air or wind or other pressure in the sewers can have no influence on the seals of interior fixture traps, but where an intercepting house trap is used, it is clear that a sewer vent must also be furnished at the trap to protect it from such influences. The influences which act within the house pipes to create back pressure are : First, the compression of the air in the main soil pipe by waste water passing through it ; second, the pressure of the wind ; and third, the suction of open fires and ventilating outlets throughout the house. If a large body of water is thrown suddenly into the soil pipes from one of the upper fixtures in a house, it drives the air in advance of it as it falls like a plug through the pipe. Were there no resistance to the passage of the air, such as is caused by friction, or a sudden bend in the pipe, the air would pass through a properly ventilated pipe in front of the water without compression, but the rough interior of the soil and waste pipes, and sudden bends in their course, causes considerable resistance to the escape of the air in advance of the water, causing condensation of the air, and giving rise to the phenomenon we are dis- cussing, and this "back pressure" is sometimes strong enough to drive the water out of the traps in a sudden jet or fountain. I have completely emptied a 4-inch pot trap, having a seal four inches deep, by this action, even though the soil pipe was properly vented at both top and bottom. Fortunately, however, a very simple remedy exists for back pressure. This force never exceeds a few ounces to the square inch in properly arranged plumbing, and may easily be resisted by a column of water from 12 to 18 inches in 299 Plumbing and Household Sanitation. height. Hence a trap which would be completely emptied when standing alone, as shown in Fig. 252, 276 or 278, will easily resist the pressure when attached to and placed some little distance below a fixture or when the inlet arm is simply lengthened as shown in Fig. 277. With a common S trap the resistance to back pressure in this figure is twice as great as in the first. The limit of resistance of an S trap is the weight of a column of water twice as high as the Fig. 276. Effect of Back Pressure. Fig. 278. Effect of Back Pressure. Fig-. 277. Back Pressure resisted by posi- sition of the Trap below the Fixture. depth of its seal. But though the soil pipe air may be blown through the trap when it surpasses the limit of resistance of the seal, yet the fixture above the trap will catch the water thrown up and restore it to the trap. With a pot trap, however, the power of resistance is much greater, since it contains water enough to rise under the influence of back pressure to a very considerable height in an inlet pipe. Now, so far as my experiments have shown, the severest back pressure that can possibly be brought to bear upon a water trap in a properly plumbed 300 Water Flushing. building having ventilated soil and drain pipes can be re- sisted by a column of water from 14 to 16 inches high. Hence, if. a trap in such a building is placed under a fix- ture in such a manner that the bottom of its seal shall stand from 14 to 16 inches below the outlet of the fixture it serves, it may be considered perfectly safe against loss of seal or soil pipe air transmission by back pressure. For it will be found that if the column of water in a trap is high enough to resist this back pressure, it will entirely exclude the entrance of sewer gas or soil pipe air so compressed in the pipes. In other words, the air will not, under such circumstances, ever be driven through the water column in bubbles, as is sometimes feared. Hence in setting traps under kitchen sinks where back pressure from water fall- ing from fixtures above is to be feared, the traps should always be placed low enough below the outlet of the sink to permit of the formation of a water column high enough to resist the back pressure. Otherwise the water may be blown out of the trap into the sink, and sewer air will fol- low. If such action follows every time any fixture above is discharged, the constant repetition of such injection of sewer air into the room may result in serious consequences. Now, the main house trap is a frequent cause of heavy back pressure in the basement of a house owing to the friction caused by the resistance of its seal, and this fur- nishes another argument in favor of its abandonment. In the experiments in back pressure made in my inves- tigations for the Board of Health, the traps were tested on the basement floor (see Fig. 242) just above the hori- zontal run of the soil pipe. The tests were divided into (A) those in which the traps had no vertical extension of the inlet arm, and (B) those in which the inlet arms were extended. An S trap having the ordinary 6-inch length of inlet arm 301 Plumbing and Household Sanitation. above the seal was first tested. The first discharge of the water closet alone threw the water out of the trap, pro- jecting it several feet in the air, and .broke the seal. The experiment was often repeated with the same rsult. Fig. 278. (A) A 4-inch pot trap lost its seal in four discharges (see Fig. 276). The top of the inlet arm stood 2 inches above the top of the seal. An 8-inch pot lost 2 inches of its seal in seven discharges. The top of the inlet pipe stood 3 inches above the top of the seal. The same trap lost 3^4 inches by fourteen discharges of the water closet and bath tub together. (B) With a vertical extension (Fig. 2jy) 01 16 inches, a 13/2-inch cast lead S trap retained its seal entirely whether tested with the discharge of the water closet alone or with water closet and bath tub together; but in all cases air was forcibly driven through the water forced up into the inlet pipe, because the volume of water in the trap was insufficient to outweigh the back pressure. An S trap having 5 inches of seal without extension lost its seal in all cases, but with an extension of 16 inches the water was not thrown out under die severest dis- charges. With this trap, moreover, the large volume of water was with the extension sufficient to overbalance the pressure of the air, and no bubbles were driven through the trap. The same deep seal S trap was then tested after half its seal had been removed as by evaporation or other accident. In this case the trap acted exactly as did the ordinary shallow-sealed, ordinary cast lead S trap, and al- ways allowed air to be driven through it. A 4-inch pot trap with the 16-inch extension neither lost any of its water nor allowed any air to escape through its seal under any of the severest conditions. 302 Back Pressure. The same trap with a 6-inch extension, bringing the top of the extension 8 inches above top of seal, lost its entire seal in two discharges of the water closet and bath tub together. The volume of the water in the trap was suffi- cient, but the pipe was not long enough to allow of the formation of a column sufficiently high to resist the air pressure. An 8-inch pot trap with either a g, 12 or a 16-inch ex- tension lost no water and allowed no air to pass under either of the tests. But with a 6-inch extension the water was driven out of the trap. A piece of 1 ^2-inch waste pipe, 12 inches long, holds about 24 of a pint of water. A 15-inch piece holds a pint. Hence a trap used with such a waste pipe should have a capacity of not less than ^4 pint. In our apparatus erected for this course we shall be able to illustrate "back pressure" in every degree of force, from an amount scarcely measurable up to that which will throw the entire contents of our tank upon the lecture floor, according as the valve just below the trap testing branch be left open or completely closed. 303 CHAPTER XVIII. Evaporation. 1X7 1 T H unventi lated traps evaporation of their seal goes on with ex- treme slowness, and with such traps contain- ing a consider- able body of water, no dan- ger from this cause need be anticipated un- less the build- ing be left un- occupied and unwatched for years at a time. If the trap is adequately ventilated, however, its seal will be gradually lowered, and if the ventilating flue con- nects with the trap at or near the crown, the induced air current licks up the water with a speed proportional to the efficiency with which it performs its duty as a venti- lator, and will destroy the seal of an ordinary small S trap in from four days to one or more weeks, according to the rapidity and dryness of the current. If the flue connects with the trap at any point below its seal it is powerless to prevent self-siphonage. 304 Fig. 279. Diagram illustrating the Air Movements above the Water Seal of a Back Vented S-Trap, and of a non-vented Antisyphon Trap. The former quickly losing and the latter retaining its seal. Evaporation. Some years ago, after the enactment of the trap vent law, the Brooklyn newspapers published, in the interest of the public, the following warning, showing that the of- ficers of the Public Health Department had already ex- perienced some of the evils of the trap vent law : "The Commissioner of Health desires to direct the attention of householders to the danger of occupying houses which have been for any considerable time without occupants. It is the practice of many persons to leave their dwellings for several months in the summer, during which time the water in the traps of basins and other fixtures is liable to evaporate, and thus permit the unobstructed entrance of sewer gas into the dwellings. When the families return in the fall they are exposed to these sewer emanations, and it is believed that cases of serious, if not, indeed, fatal sickness have been due to this cause. Whenever houses are so left, provision should be made to have the traps filled at least every two weeks by a competent and trust- worthy plumber, and if possible to have all the windows of the house opened for twenty-four hours before its re- occupation." This notice was given the public after the city had fastened upon them the trap vent law. They then felt constrained to advise every house owner, under peril of serious danger to health, to employ some honest and skilful expert to stand constantly on the alert to undo the danger done by this law. We will not calculate here the number of traps owned by the several million inhabitants of Greater New York, nor the exact size of the army of trustworthy plumbers which would be required to overhaul dwellings for the purpose of attending to apparatus in- tended to be made by the new law automatic. But were all the traps ventilated in accordance with this law, it is certain that their fortnightly refilling and the opening of all the house windows in consequence of their not having 305 Plumbing and Household Sanitation. been refilled weekly would consume infinitely more time than would be required to clean out the same number of unventilated pot traps, if their use was the only alternative, as often as their condition required, and, as a collector of greasy sediment, the vent pipe is no better than an elongated cesspool trap itself. Had the Commissioner of Health published advice to the householders to employ some competent and trustworthy plumber to cork up or tear out once and for all from their houses all these incompetent and untrustworthy back vent pipes which were responsible for the trap seal evaporation, instead of raiding the prem- ises every fortnight to try to repair in a measure the mis- chief they had done, he would have performed a really valuable service to the alarmed and unhappy absentees on their summer vacations, and have reassured the much-suf- fering public at large at the same time. Sometimes an owner is advised to fill all the traps with oil as security against evaporation. This method is trouble- some and expensive, and should the house owner or any of his friends or employes happen to require to visit the prem- ises during the season of its inoccupancy, he would be obliged to obtain or carry with him on each occasion a gal- lon or so of oil and refill the traps of any fixtures used during such a visit. Inasmuch as such phenomenal fore- sight could hardly be expected, especially in cases of un- expected or unforeseen visits, the practical objections to this method are sufficiently obvious, though it often sounds well to propose it. While it is evident that back venting must gradually de- stroy the seal it was commissioned to protect, it is also evident, as an examination of our Figure 279 will make clear, that a pot trap or an anti-siphon of good water capacity is capable of preserving its seal against loss 306 Evaporation. by evaporation during an entire winter or summer season if un vented. If vented, a current of air is constantly in motion over the seal when the vent pipe is actually performing the office for which it is installed, and it carries off vapor from the seal as fast as it rises. One may easily test this by filling a large pot trap having arms long enough to reach to the floor and to a basin and placing it by the side of a cup of water as shown in Fig. 279. In my experiments for the City Board of Health the evaporation is shown to be very rapid from the sewer side of a vented trap and almost nothing from the house side of the same trap. Experiments for the Board of Health on Evaporation Produced by Back Venting. These experiments were made on the basement floor. They were subdivided into (A) those in which the vent pipe was conducted into a cold flue, and (B) those in which it was conducted into a heated flue. (A) Tests with a Cold Ventilating Flue. A 1 % -inch S trap having a seal 4^$ inches deep was attached to the end of the branch waste in the manner shown in Fig. 242, A i^-inch rubber ventilatng pipe was taken from the 1 54 -inch ventilating opening at the crown of the trap and conducted into a cold 4-inch galvanized iron ventilating flue, shown in the drawing. This flue passed through two occupied offices (basement and first floor) whose temperature was maintained at about 68 degrees F. during the term of the experiments, and through a chemical laboratory (second floor) whose temperature was main- tained at about 60 degrees F. For the remainder of its height the flue passed through a cellar and stairways whose temperature was maintained at about 45 degrees F. No 307 Plumbing and Household Sanitation. artificial heat was applied to the flue. The velocity of the movement of the current of air in the flue was measured by the anemometer. The daily rate of loss of seal by evap- oration and the velocity of the current in feet per minute is shown in Fig. 281. We see that the loss averages about an eighth of an 7.m_ % _ 9 —I ^/ u S3 IS /6 /7 79 20 2/ 22 23 24 — 26 _ 2? 2? 30 3*' \A$/ 2 #* f6 *7 J? 2d M^4 Fig. 281. Record of Evaporation Fi S- 2S2. Record of Evaporation with Cold Flues. with Heated Flues. inch per diem. It amounts to about a quarter of an inch the first day, and gradually diminishes as the level of the water descends in the trap, and the distance of its surface from the ventilating current increases, to a little less than Y% inch per diem. Hence an ordinary S trap having a 13/2-inch or a 1 ^4-inch seal might lose its seal in from nine to eleven days under similar conditions. The experiment was repeated several times at different 308 Evaporation. parts of the year from the middle of December to the middle of May, with substantially the same results. The same trap was now tested at the middle opening, whose center was 2 inches below the crown. The rate of evaporation was somewhat slower, as shown. This ex- periment was carried on only n days, inasmuch as by this time i l / 2 inches of the seal had been destroyed, and the seal of many ordinary S traps does not exceed i^ inches or 1 24 inches. The same trap was now ventilated at the lowest point, i. e., 6 inches below the crown. The evapora- tion in this case was exceedingly slow, and after the first two or three days was almost inappreciable. A number of experiments were then made on S traps unventilated, but open at both ends, as is the case in prac- tice. The loss of water was almost inappreciable, not ex- ceeding i -32nd or i-i6th of an inch in ten days. (B) Experiments on Evaporation Produced by a Heated Ventilating Flue. A i^-inch trap having a seal 3%. inches deep was tested. A i^-inch wrought iron gas pipe 6 inches long connected with the crown, of the trap with a brick flue 8x12 inches heated by a stove. (See Fig. 282.) The diagrams shown in Fig. 282 represent five tests, two made in March, one in October, and two in November. Here again the perpendicular lines represent the depth of the seal of the trap. The upper arc represents conven- tionally the outlet mouth and the lower arc the inlet mouth of the trap. The horizontal lines show the position of the water level in the trap at the same hour in the morning of each day recorded in figures on the diagram. We see here a very rapid diminution of the seal. The average loss per diem exceeded 1/3 of an inch. The smallest loss is % inch, 309 Plumbing and Household Sanitation. and the largest nearly y% inch. The fixture side of the trap was closed during the tests. A second series of experiments was made with an ordi- nary i^-inch cast lead trap having a seal \]/ 2 inches deep. The trap was connected with the heated flue at a point 3 inches below the crown. Four tests were made. The loss of seal was much slower than in the former tests because of the distance of the mouth of the vent pipe from the top of the water. The rate of evaporation, however, in these four tests averaged one-seventh of an inch a day, the greatest loss in any one day being % inch. In all these experiments on evaporation it was found to make no ma- terial difference in the results whether the fixture end of the trap was open or closed, showing that the evaporation at this point was inappreciable. In the experiments on evaporation with the cold ventilat- ing flue, in the first experiment with the vent at the crown, the anemometer recorded an average rate of movement of the ventilating current of 94 feet per minute. In the second test, with vent at the crown, the average was 85 feet per minute ; with the vent 2 inches from the crown the average was 109 feet per minute. The velocity of the current during the cold months of the year was quite uniform. In the summer months, however, it was exceedingly variable, sometimes equaling that of the cold season and sometimes ceasing altogether, or retrograding. In the cold months the relation between the rapidity of evaporation and the velocity and dampness of the air cur- rent was not accurately determined, the rate of evaporation being quite uniform in spite of considerable barometric fluctuation and change of velocity. But in summer a change of the conditions of the atmos- phere produced a very marked change in the rate of evapo- ration. On a few occasions of damp or rainy weather in 310 Evaporation. the summer months, where the cold brick flue was used without a ventilating cap on top, the seal actually gained slightly in depth from condensation on the cold flue of the damp air of the soil pipe, or from an actual descent of moisture down the chimney. These accretions, however, were very rare, not occurring more than three times in the whole duration of the experiments. The scientific investigation of this branch of the subject would require more elaborate apparatus and much more time than was at our disposal ; yet what records we made were made with great care and accuracy. From these experiments we found ( I ) that a rapid evaporation of the water seal of traps takes place when they are ventilated at or near the crown, and that the evapo- ration goes on both in winter and in summer, and in ordi- nary unheated flues as well as in flues artificially heated. The evaporation is most rapid in winter or with flues arti- ficially heated, and slowest in summer, especially in damp weather. Hence it may be stated generally that the rapid- ity of evaporation depends upon the velocity, temperature and hygrometric condition of the atmosphere. (2) That in winter the evaporation produced by ventilation is so rapid as to destroy the seal of an ordinary i^-inch ma- chine-made S trap in from four to eleven days, according to the nature of the current. (3) That without ventilation, or with the ventilating flue taken from a considerable distance below the crown, the evaporation of the water seal of traps is exceedingly slow, and that unventilated traps having a considerable water capacity may be considered perfectly secure against this danger unless they are unused for years at a time. It would obviously be impossible to devise a form of apparatus for experimental purposes which should cover all the varying conditions liable to be met with in plumb- 311 Plumbing and Household Sanitation. ing practice. The position of the trap on the soil pipe branch, the manner and position of connection of the branch with the main pipe, the amount of usage the pipes sustained, the manner in which the ventilating flues were constructed, would all produce their effects upon the re- sults. Nevertheless, in every case where the ventilating flue performed the office of producing a movement of the air within the pipes for which it was intended, and this air was not absolutely saturated with moisture, an event very rare in well ventilated sewers and house drains, the evapo- ration must of necessity go on in the manner recorded as the result of these experiments. How far the variation of the conditions would affect the rapidity of the loss of seal must be left to other investiga- tors to determine, and it is hoped that the National Board of Health will x at some early day take up this whole matter, and by a most thorough and judicial series of exhaustive experiments put a final end to all doubt and discussion on the part of the public in this extremely important depart- ment of sanitary building. The apparatus used in our tests for the Boston Board of Health was fitted up exactly as is customary to fit up plumbing for actual use. The entire length of the soil pipe was kept much of the time wet during the experiments on evaporation, by dis- charges through it made for the tests on siphonage and back pressure, precaution being of course taken by having the inlet end of the trap always corked up so as to be secure against loss of seal through these agencies. The inlet at the end of the soil pipe system, where the fresh air was taken in to produce the ventilating current above the trap, was distant as much as 60 or 70 feet from the traps tested, so that the air was obliged to traverse a con- siderable length of damp soil pipe, the greater part being 313 Evaporation. nearly horizontal, on its way to the trap, and it may there- fore be assumed it was conducted over as large an area of moist surface as it would ordinarily encounter in practice. Moreover, the results of our experiments in this direction correspond with the experience of many sanitary engineers, health inspectors and plumbers who have had occasion, since the enactment of the plumbing laws in various parts of the country, to observe the effect of the provision re- quiring branch ventilation on the water seal of traps. General Conclusions from the Experiments on Siphonage, Back Pressure and Evaporation. From these tests I conclude as follows : (i) The ordinary form of machine-made small S trap with shallow seal and without special ventilation is in- capable of resisting the action of siphonage or back pres- sure, even in a very mild form. (2) A small S trap even when made of unusually deep seal is incapable without special ventilation of resisting the action of siphonage or back pressure in a mild form. (3) Small S traps when ventilated at the crown, with vent pipes having a diameter the full size of the bore of the trap, and of no unusual or excessive length, are in- capable of resisting the severe action of siphonage pro- duced by the simultaneous discharge of any powerful flushing water closets and ordinary bath tubs under ordi- nary conditions likely to be encountered in practice. Water closets producing a powerful flushing of the soil pipes when discharged should not be prohibited on account of their siphoning power, because the periodical flushing of the soil pipes by their use is productive of great good, and their siphoning action may be counteracted by other means. (4) Special trap ventilation when the vent pipe is ap- 313 Plumbing and Household Sanitation. plied at or near the crown of the trap induces a current of air over the water which rapidly destroys the seal. (5) Trap ventilation when the vent pipe is applied at a point so far below the crown as to avoid the danger of evaporation leaves the trap open to the danger of self- siphonage, as well as of severe siphoning action. The posi- tion of the vent pipe on the trap does not (at least within the limits covered by our experiments) materially affect the action of siphonage. (6) Pot traps of the ordinary sizes are incapable, without special trap ventilation, of resisting the severest action of siphonage liable to be encountered in plumbing. (7) Pot traps of the largest size are open to the objec- tions attending all cesspools, and should never be allowed. (8) Anti-siphon traps, may be constructed in such a manner as to resist permanently, wthout back venting, all the adverse forces to be encountered in plumbing. 314 CHAPTER XIX. Capillary Action. Fig. 283. Capillary Action Forming Short Siphon. ESIDES the well known enemies of the water seal of traps already described, an- other exists which is, however, more in- sidious and no less fatal in its action. It works like the vampire, silently and stealthily, drawing the life from the trap without warning of any kind, and often leaves open the gates of the sewers with- out detection. Where the trap is con- structed entirely of opaque material the absence of the water seal cannot be seen, and where glass is used it soon becomes coated with an opaque film, so that the source of the leakage of sewer air into the house cannot be seen and, as capillary action is unsuspected, the presence of sewer air is attributed to some other cause. Capillary action is the subtle thief which does this mis- chief. Hairs, lint, bits of twine, paper, sponge or matted fibrous filth of a great variety of kinds are the tools with which it operates. A small quantity of any of these sub- stances, forming a continuous mass or chain from the water in the trap to and over into the outflow, will, under certain conditions, soak up and slowly drain off the water from the trap until the seal is destroyed. Let us examine the con- ditions favorable to this action and ascertain by what means, if any, it may be prevented. In books on the subject of capillarity we find the theory explained with scientific accuracy. The precise amount of 3 1 5 Plumbing and Household Sanitation. elevation of liquids in tubes of very fine bore, nominally of the diameter of a hair (capilla), is calculated in these treatises to a nicety, and we are in some of them referred for complete satisfaction and elucidation particularly to the gigantic work of La Place on ''Celestial Mechanics" (tenth book, supplement). Knowing from the study of this interesting work that the tension of the surface of contact of two liquids or bodies is represented by the equation T V2 =/ E (*> ~ **) A +/**(** ~ *)//*, what more need the practical plumber have to cause the whole subject of the capillary effect of sediment in traps and the best methods of dealing with it to burst upon his delighted understanding in a flood of light? All he requires is a knowledge of the higher mathematics and some skill and ingenuity in arranging his data for calculation. He knows from the treatises that the finer the bore of the tube the higher the liquid will rise in it, provided the surfaces are of a kind the liquid can wet ; that plane surfaces which can be wetted by a liquid will exert a similar attraction on liquids, provided they are put near enough together, not exceeding i-io of an inch apart, and that the attractive power is in proportion to the proximity of the surfaces and independent of the thickness of the bodies underlying them. But he will not find in the treatises what the exact efTect will be on liquids of the interposition of numerous plane and rounded surfaces such as are presented by the sediment found in traps, under the peculiar conditions of surroundings, temperature and moisture met with in plumbing. Inasmuch as these peculiar conditions would render his calculations somewhat more complicated and difficult, and as the books have not investigated the subject 316 Capillary Action. sufficiently, a study of this particular branch of the subject from a practical rather than a theoretical standpoint seems needed. What is the capillary effect of large and small quantities of the sediment found in traps, and how can the loss of water by this agency be prevented? It is evident, first, that the substances exerting the capillary action can conduct the water only to a certain limited distance above and beyond its surface, and that the rapidity of the removal of the water in a closed vessel will be in proportion to the shortness of the distance required to be raised ; second, that capillary action in an open vessel greatly. increases the loss by evaporation, and that the rapid- ity of the removal of the water in vessels of similar form but exposed to different degrees of change of air will be in proportion to the velocity and hygrometric condition of the air currents. Hence, if we use a trap having a seal of proper form, and do not allow the air above the trap to be changed in such a manner as to cause evaporation, aggra- vated by the spreading out of the water through capillary action, the trap will be secure against loss of seal through this agency. To ascertain the distance which water will travel above the seal of a trap under the influence of capillary action, a number of experiments were made with various materials, such as are liable to collect in traps in practical use, includ- ing among them those which are found to have the maxi- mum of effect in conducting the water by capillary action. The experiments were made both in ordinary open glasses and in different kinds of traps, both open and closed. The first tests were to ascertain the perpendicular dis- tance. Figs. 283 to 286 show the manner in which I made the tests with ordinary goblets. A number of these glasses were supported on blocks and filled with water. Over 317 Plumbing and Household Sanitation. their edges were hung the different substances to be tested, one end extending below the bottom of the water in the goblet, and the other to the top of a tumbler placed below it, as shown in the figures, to receive the water drawn from Fig. 284. Capillary Action Forming Longer Siphon. Fig. 286. Capillary Action with Horizontal Extension. Fig. 285. Capillary Action with Long Siphon. the goblets. The substances tested were matted hair-felt, lamp-wicking, both with and without its covering; jute; hemp-cord, unraveled and separated into fine fibres ; hemp- cord in its natural braid, and pieces of string. Of all the 318 Capillary Action. substances tested, jute, such as is used by plumbers in caulking joints, proved to be the most effective in removing the water by capillary action, and this is the substance 1 shall use in our tests to-night. Different amounts of each substance were used in making the experiments. In each case experiments were made both with a small quantity of each material and with a mass large enough to complete- ly fill the waste pipe. As might be expected, the water was most quickly removed when the quantity of the sub- stance tested was large enough to completely fill the pipe. These experiments showed the limit of the carrying power in an upward direction with these materials under capil- lary action to be 4^ inches. The water was rarely lifted more than 3 inches or 3^4 inches. The majority of the wa- ter carried into the lower glass was moved during the first ten or twelve minutes, the rapidity of the action grad- ually decreasing as the water descended, becoming extreme- ly slow when the level was reduced about 2 inches, and generally ceasing altogether and the fibres becoming entirely dry at the top when the water in the upper vessel was reduced about 3^2 or 4 inches. In emptying a vessel of water by means of a bent tube forming a siphon, the excess of length of the outer over the inner limb of the siphon governs, as I have shown, the rapidity of the flow. With capillary action, how r ever, though the outer limb must always be longer than the inner, yet beyond a certain fixed point the excess appears to have no marked influence. A small predominance of the outer limb, as shown in Figure 283, or just enough to overbalance the column of water in the inner limb, carries off the water as rapidly as the long limb shown in Fig- ure 285. The results of the experiments with ordinary open ves- sels were as follows : 319 Plumbing and Household Sanitation. (a) Hair- felt. This is a material which closely resem- bles the matted deposit of short hairs which form so large a proportion of the deposit in traps and waste pipes. Strips of this felt one-quarter of an inch thick and of various widths and lengths were tested under different conditions. Tested with the glasses arranged as in Figure 283, with a strip three-quarters of an inch wide, it lowered the water in the glass 2 inches in the first ten minutes, but required four hours and a half to diminish the level another inch. After this no more water was carried over into the lower vessel, but the rate of evaporation of the water in the goblet was considerably increased by the hair-felt, which lifted the water to a certain height and distributed it over the fibres of the felt, thereby exposing a very large sur- face to the action of the air. A piece of felt 2 inches wide tested in a similar manner gave similar results. An in- crease in the width or length of the felt did not make, in this case, an increase in the amount of the water trans- ferred from the upper to the lower vessel corresponding to the increased size, but increased the velocity. (b) Lamp-wicking. A material closely resembling the soft, porous lint formed in traps and waste pipes. This was tested both with and without its cylindrical fibrous covering, as it comes prepared in the market for use in lamps. The wicking was cylindrical in form and about 34 inch in diameter. It was first tested without its cover. Placed as shown in Figure 283, the wicking lowered the wa- ter only 1^4 inches in seventeen and one-half hours, after which no further transfer took place. Placed as in Fig- ure 284, \Yx inches were transferred in the same time. With the wicking covering on, only half the amount of water was transferred in the same time. (c) Jute. A hempen, unwoven cord, with long, fine fibres, used by plumbers in caulking. This substance pro- 320 Capillary Action. duced the strongest capillary action, and acts like very fine hair and lint. Arranged as in Figure 283, a piece *4 mcn in diameter transferred i l / 2 inches in fifteen minutes and 2^ inches in four and three-fourths hours. Another piece, 1 inch in diameter, transferred 2 inches in fifteen minutes, and the whole 4 inches in four and three-fourths hours. Another piece, supported as shown in Figure 284, raised the water 4^ inches, after which the lower end of the long arm dried up, and what water was thereafter raised from the goblet was carried off by evaporation, but not transferred to the low T er glass. (d) Hemp-cord, unravelled and separated into fibres, was in no case able to raise the water above 4 inches from its surface. (e) Twisted or braided, as it comes in cord for the mar- ket, it could not transfer more than 2 inches from glass to glass. (f) Pieces of linen twine (eight pieces) could not trans- fer more than ^4 inch. Beyond these points the various substances invariably dried up at their lower ends, after which, of course, what- ever water was taken from the upper vessel was removed by evaporation. Tests were then made on various similar fibrous sub- stances, both in the manner described and also enclosed in small, l /x -inch bent lead tubes, to prevent evaporation from effecting the action. In no case, except with sponges, could the water be raised over $ l / 2 inches, and rarely over 3 inches by these substances. The outer arms dried up before the water in the upper glasses was lowered 3 or 3^2 inches. Without the lead tubes, the outer arms dried up sooner than with them, hence less water was carried over into the lower glasses, but more was lost by evaporation. The loss of water was greater without the tubes, but the 321 Plumbing and Household Sanitation. action was slower, since the drying up of the outer arms prevented the rapid removal by the combined capillary and siphoning action. Fig. 286 shows the manner in which tests for the limit of horizontal and inclined distances were made. It was found that an increase in horizontal distance facilitated the drying of the mass, and therefore correspondingly diminished the siphoning action. I will now place pieces of jute y 2 inch in diameter in each of the three glasses on the table, just as you see them rep- resented in the picture, and in a few minutes we will ob- serve the action they have produced. The water stands in each goblet exactly on a line with the top of the glass. From the experiments I have so far described, and numerous other tests made in the same manner, we learn that the extreme limit of the lifting power of very small quantities of the long, fibrous substances which might lodge in traps so as to exert a capillary action is within three inches. Sponge is the only substance known to the writer as likely to be found in waste pipes which has a lifting power exceeding this. The limit of sponge, even in large masses, appears from the tests made at the same time with the others, to be 8 inches ; but as the general shape of a sponge is spherical, and never filiform, and as no sponge large or long enough to extend upwards this distance or anything approximating it, and then down again the same distance into the waste pipe, could possibly be squeezed into a trap without stopping up the waterway altogether, the consideration of this material and all others of similar form need not enter into our calculation. Tests With Traps. Thus far the experiments have been made in the open air in ordinary open vessels. The tests were made in the 322 Capillary Action. shade, and in a temperature varying between 60 and 70 degrees F., or the ordinary temperature of house interiors. To render these results of more practical value they should be compared with the tests made on the same materials in the actual positions found in practice — i. e., in the trap itself. The tests were, therefore, made both in detached traps and in traps fixed in position and properly attached to the drain pipe. Tests With Ordinary S-Traps. A i^-inch S-trap having i^-inch seal was arranged as shown in Figure 287. A string of jute 34 - i ncn i n diam- Fig. 287. S-Trap having its Water Seal Destroyed by Capillary Action. eter was introduced so as to extend from the bottom of the trap over the outlet and down several inches below the bottom. The experiment was repeated five times, the results each time being nearly identical. In the first half minute the water in the trap was lowered Y / 2 inch. Five minutes sufficed to lower it 1 inch, twenty minuts 1% inches ; a half-hour usually sufficed to break the seal, and about three hours was enough to leave the trap almost dry. The quantity of jute was afterward increased to 1 inch 323 Plumbing and Household Sanitation. in diameter, which was the maximum possible, inasmuch as it was sufficient to fill the trap as full as it could ever possibly get in practice. In every case enough water was drawn out of the trap to break the seal in less than half an hour. Two minutes generally sufficed to lower the seal an inch. Hair-felt emptied the trap in from nine to fifteen minutes. Tests With Pot-Traps. A number of pot-traps were then tested. An 8-inch pot- trap having 3^-inch seal was arranged as shown in Figure 288, the mass of jute being 1 inch in diameter. It required twenty-four hours to lower the water ij^ inches. Two days reduced it 1 13-16 inches; three days, if inches; seven days, 1 15-16 inches. After this no further change took place in the trap. Evaporation was too slow to make any perceptible difference in several days, since the trap was not ventilated. A vessel of water about the same size and form with the 8-inch pot-trap, but freely open above to the air, so that evaporation could go on, and having a piece of jute i l / 2 inches in diameter hanging over its edge, as in Figure 283, lost 5 inches of water in five days. A portion was car- ried over as in the 8-inch pot-trap into the vessel below, but the rest was removed by evaporation hastened by the capillary action. A 6-inch pot trap similarly arranged lost 2 l /& inches in one day, 2 5-16 inches, 2^ inches and 2 7-16 inches, in two, three and five days, respectively, after which no ap- parent further change took place, the experiment lasting several days longer. A 3^-inch pot lost y% inch, 1 inch, 2 inches, 2^4 inches, 2% inches and 3 inches in one, six, fifteen, forty-eight, sev- enty-two, 144 hours, respectively, after which no further change took place. 324 Capillary Action. Figs 288-b and 288-c show the manner in which the un- vented "Sanitas" trap is able to retain its seal under capil- lary action. The fibrous matter not being able to raise the water high enough to break the seal. The horizontal exten- sion of the unvented "Securitas" trap combined with the elevation^ of its outlet, provides similar protection. More- over, the construction of these traps is such that it would be impossible, without special manipulation, to so weave a Fig. 288. Pot Trap losing its Seal through Capillary Action. Fig 288e. Securitas Trap. Fig. 288d. Securitas Trap Antisiphon Traps Resisting Capillary Action. mass of fibrous material through the trap that it could con- nect the lower with the upper bend in such a manner as to place the former within the influence of capillary attraction. This reasoning was corroborated by prolonged tests. Thus we see that the effect of capillary action in traps detached from the drains is similar to that in open vessels, with the exception that in traps unventilated no percep- tible loss took place through evaporation, and that after the limit of perpendicular distance at which the capillary force 325 Plumbing and Household Sanitation. can act has been attained, no further loss of water is per- ceptible. In open vessels, on the contrary, the draught on the water goes on indefinitely by rapid evaporation aided by the distributing process effected by the capillary action. Tests of the Effects of Capillary Action in Venti- lated and Unventilated S-Traps Fixed in Position. To test the loss by capillary action on ventilated S-traps as compared with the loss on the same when unventilated I attached an S-trap having a 4^8-inch deep seal to a branch waste entering the soil pipe, after having half filled the trap with jute as shown in Figure 288. With the trap unventilated the loss by capillary action was as follows : In the first five minutes ^2 inch ; in the first forty-five min- utes 1 inch ; in twenty-four hours 3 inches ; in three days 3*4 inches ; in four days 3^ inches. Thereafter no further perceptible change took place. It made no perceptible difference whether the basin side of the trap was opened or closed, showing that evaporation in an unventilated trap is practically imperceptible. The experiment was then repeated on the same trap, ventilated at the crown, into a cold flue with the following result: In one hour i l /% inches had been removed; in 5 hours 1% inches; in 22 hours 2]/ 2 inches; in two days 334 inches; in 3 days 3^ inches; in 4 days 3^4 inches; in 5 days 4 inches. Thus the loss continued at the rate of about 34 mcn a day by evaporation, after the outer end of the jute mess had entirely dried up. This rate of evapora- tion was nearly double what it would have been had it not been assisted by the capillary action. From this we see that ventilation greatly increases the danger arising from capillary action, often rendering the latter dangerous in cases where, without ventilation, the seal would not have been broken. 326 Capillary Action. To test this point still further I placed two ordinary drinking glasses, filled with water side by side. The first was treated as shown in Fig. 284, with a mass of jute hung nearly 5 inches above the surface of the water and having one end immersed in it as shown in the figure, the other extending below the bottom of the glass. Owing to the height from which the jute was suspended the water did not rise to the point of support ; consequently the outer arm was dry, and whatever loss of water was observed was, therefore, due to evaporation. The glass having the water alone lost by evaporation only 34. mcn m seven days, while that having the jute lost 1 inch, or four times as much in the same time. Friction. A consideration of very great importance in trap con- struction and arrangement is the amount of retardation to the passage of the waste water caused by the friction against its interior surfaces. In order to obtain the quickest delivery and maximum of scouring action on the waste-pipes below the trap, it is important that the {rap should afford the minimum of obstruction to the flow of the water. Many traps, espe- cially gravity-ball and other mechanical traps, are so formed as to greatly retard the flow of the water. With many ball-traps, when the water is permitted to escape from the fixture through the waste pipe "full-bore" above the trap, the ball is so forcibly driven against the outlet mouth of the trap as to very seriously obstruct its further pas- sage, and prevent its exerting its full scouring effect on the pipe below. An ordinary S-trap offers the least resistance to the flow of the water, the gravity ball trap the most, if we except certain forms of mercury-seal traps. 327 Plumbing and Household Sanitation. An ordinary bath tub arranged as shown in Fig. 243 will discharge through i^-inch waste pipe, 9 feet long, de- scending perpendicularly and without a trap, at the rate of 1.4 gallons of water per second. An ordinary unventilated i^-inch S-trap, with a seal iy 2 inches deep, will retard the flow only 23 per cent, or it will discharge at the rate of a little more than one gallon a second. Another i^-inch unventilated S-trap emptied the tank at the rate of 1.1 gallons a second. The same trap ventilated prolonged the time of empty- ing the tank from 90 to 113 seconds, thereby retarding the flow 23 seconds or 26 per cent. The ventilation also created a loud and somewhat terrific roar during the en- tire duration of the discharge caused by the suction of the air at the vent opening. Without any trap, the tank dis- charged in 73 seconds. With a hinged valve trap, unven- tilated, it required 126 seconds. With the same trap ven- tilated a very much longer time or 163 seconds was re- quired ; the ventilation retarding the flow 37 seconds or 30 per cent. A 4-inch pot trap, unventilated, required 104 seconds. The same ventilated required 144 seconds, or 38 per cent. A 4-inch bottle trap, unventilated, required 94 seconds. A gravity ball trap required 226 seconds. In both of these ventilation reduced the flow from 30 to 35 per cent, by calculation. Thus we see that the average retardation of the dis- charge from a bath tub, and the consequent loss of scour- ing effect, caused by ventilation, is very great and amounts to about 30 per cent, or nearly a third of the whole when the outlet is arranged to discharge through a perpendicular waste "full bore } " and where the vent pipe is short. When 328 Friction. a long vent pipe is used the percentage of loss is somewhat less. The discharge of a wash basin having an outlet large enough to fill the waste-pipe " full-bore" gave similar rela- tive results for different traps. Summary of Ten Objections to Special Ventilation. I find, therefore, no advantage whatever in trap venti- lation. The disadvantages, however, are very serious, and may be summed up briefly as follows : (i) It destroys the trap seal by evaporation when ap- plied at or near the crown. With S-traps this position of the vent is necessary to prevent self-siphonage. (2) It can not always protect the trap from siphonage even when newly applied in the most approved manner. (3) It increases the unscoured area of the trap, making it a cesspool. It is a very strange piece of inconsistency to condemn the cesspool trap on account of its unscoured chamber and yet adopt in its place a ventilated S-trap, because by so doing the very thing we wish to avoid is reproduced in an aggravated form; the mouth of the vent pipe forming a sediment chamber which is not only greater in extent of surface, more easily fouled and less easily cleansed than that in the pot trap, but one which is far more dangerous in as much as its fouling, even to a lim- ited extent, involves the destruction of the whole system. I have found by repeated tests that the water discharged from a large outlet basin and trap placed where it should be near the floor, is thrown up from 10 to 18 inches into the vent pipe at every discharge. Thus a large sediment chamber is formed which has an area of nearly 100 square inches. Beyond this, congelation of fatty vapor fouls to 329 Plumbing and Household Sanitation. an indefinite extent, and it is no uncommon thing to hear of a vent pipe filled with grease for several feet above a sink trap. (4) It retards the outflow of the waste water and its consequent scouring effect about a third when arranged to discharge perpendicularly "full-bore." (5) It complicates the plumbing and adds to the dan- ger of leakage through bad joining and increased mate- rial. (6) It aggravates the danger arising from capillary action. (7) It increases the corrosion of branch wastes by re- tarding the rapidity of flow and scouring effect allowing sediment to collect more rapidly than it otherwise would, and brings soil pipe and sewer air in contact with the branch wastes to take the place of the pure air of the house, which follows every discharge of the fixture. More- over, as soon as the mouth of the vent pipe begins to get clogged by sediment and grease, the air current it was intended to produce is partially or wholly arrested, and we then have an interior surface of foul piping equally exposed to corrosive action with the unventilated pipe, but more than double in quantity. (8) Finally it seriously increases the cost of plumb- ing, an increase which amounts to as much as from five to ten per cent on the total cost of the plumbing in new work, and indefinitely in old work in which the trap ventilation sometimes becomes by far the greatest part of the work to be done. 330 CHAPTER XX. By Passes. r25a77t2Z& Fig. 289. One of the evil ef- fects of the complica- tion of piping due to ^ the trap vent law is 3 that it renders the ^N plumbing more diffi- cult to arrange, re- pair, and understand. The proper placing of the vent-pipes of- ten requires considerably more skill on the part of the work- men than is expected of or found in them. The result is a very frequent misplacement of the pipes, which sometimes remains undiscovered by the plumber, and even by the own- er, until made known by foul odors or more serious evils. Figs. 289 to 2Cfi> illustrate the manner in which this com- plication leads to trouble. The vents in these cases were all put according to the letter of the plumbing law, and seem at first sight to be correctly placed, but upon closer examination it will be discovered that they are not only themselves utterly valueless as ventilators, but that they destroy the value of all the traps. They form by their peculiar combinations open passageways for the entrance of sewer-air from the soil-pipe into the house. The er- rors appear to have been brought, after the completion of the work, to the attention of the board of health. These first five drawings are from the ''Sanitary Engi- neer." The arrows show the manner in which the sewer- 331 Plumbing and Household Sanitation. air may find its entrance by circuitous route into the dwell- ing. In Fig. 289 three fixtures are trapped and vented. The wastepipe of the wash-basin enters that of the bath-tub in- side of the bath-tub trap. Had it entered beyond the trap, the difficulty would have been avoided. But inasmuch as it is not unusual, where no vent-pipes are used, to enter Fig. 290. Fig. 291. short branches on the house side of the trap, the error is not an unnatural one for the plumber to make. It is one which is not easily detected at a glance, and which might never be observed by the house-owner or anyone who was not an expert. The warmth of the air. in the house and the draught of the fire-places would often be sufficient to create a reverse current in the vent-pipe, and produce the movement shown by the arrows. It will be observed that 332 By Passes. the bath-tub trap is vented on both sides. The effect of this is to increase the destructive action of the ventilating current on the water seal of the trap. An S-trap, having the usual depth of seal of i^ in. or 1^4 m -, would lose this seal in a few hours if the current were rapid, or within two or three days with an ordinary current. The water closet trap being, as shown, larger than the others, a cur- FiR. 29! Fig. 293. rent might easily be formed over the bath trap simulta- neously on both sides of the trap. Figs. 291, 292, 293 give similar examples. In all cases the mistake lays in entering the waste of one fixture on the wrong side of the trap of another. In each illustration one of the traps will be found to have a double action ex- ercising against its water seal. As here arranged, we have excellent conditions for pro- ducing self-siphonage of the wash-basin trap. When a 333 Plumbing and Household Sanitation. basin having an outlet as large as the one shown is dis- charged by lifting the plug it will fill its waste pipe " full- bore," and the contents of the basin up to its overflow opening will fill the pipe full as far as to the horizontal runs of the pipe. This long arm of the siphon will at once pull over the water in the short arm as soon as the basin is empty, and the suction on the trap will continue until the water column has traversed the entire length of the branch waste, thus giving the siphoning action ample time to suck out any water that may trickle down into the trap from the basin after the discharge. This action will be the more positive the longer the branch waste and the greater its pitch, attaining its maximum with the perpen- dicular position of the waste pipe. Fig. 294 exhibits still more forcibly the absurd confusion this system leads us to when we attempt to carry it out com- pletely in its logical consequences. We have here the vent and waste pipes for three simple fixtures, which are taken with some modification from a house in New York, where they have been exhibited with pride by their perpetrators. These fixtures and arrangements are repeated on each of several stories. We have shown only the waste and vent pipes. When to these, we imagine, are added the neces- sary hot and cold water supply and service pipes, we can form a pleasant idea of the condition of things our "branch- waste" ventilating engineers are bringing us to. The fix- tures have the double vent, recommended by some of our sanitary engineers and plumbers. The upper vent enters a flue or pipe heated by an interior steam-pipe, as shown, and is called the overflow and local vent pipe. None of the shallow traps used could withstand the action of these strong air-currents more than a few days or even hours. In consequence of this, house-owners often close up the overflow openings of wash-basins and bath-tubs with putty 334 By Passes. or corks in the hopes of rendering themselves secure against the odors resulting from evaporated trap seals. And this closure of the air supply to traps through overflow pas- sages greatly increases the danger of trap siphonage, as we shall hereafter show. Fig 294. Observe the complication of the plumbing involved by the use of these wriggling, interwining ventpipes, which, like venomous snakes, literally crawl about, ready to poison as well as puzzle and alarm the unhappy houseowner or 335 Plumbing and Household Sanitation. plumber who unskillfully handles them, with the noxious vapors which they are designed to carry off in their bodies. In the economy of nature the serpent is found to have cer- tain useful purposes, but the trap-vent has none, and should suffer the serpent's curse and be crushed out of existence as soon as possible. One of Boston's leading plumbers said to me one day : "We know perfectly well that the 'back-vent' law is an imposition upon the public, but the law was brought about by the influence of the early sanitary engineers and the san- itary engineers must, therefore, be the ones to get it taken off again." But the plumbers are doing better than this remark implied, for many of them are co-operating with the sanitary engineers in their efforts to have this burden re- moved. The public are becoming so much alarmed at this increas- ing complication that they are reducing the conveniences of plumbing in their buildings to the smallest amount pos- sible, where its comforts might otherwise be enjoyed in per- fect safety. It is throwing an undeserved distrust upon the whole system of water-carriage. Past Experiments on Siphon age Made by Hellyer, Waring, Philbric, Bowditch, and Others. The experiments on the effects of siphonage made and published in this country and in Europe before those I have already described, were made chiefly with pan and hopper closets, and in such a manner as to produce a much feebler siphoning action than is obtained by the use of valve or plunger closets. A pan-closet produces a very slight siphon- ing action, and this closet is comparatively seldom used to-day, although it is by no means extinct. Valve and plunger closets are fast giving way to the improved forms 336 By Passes. of hopper closets, but there are, nevertheless, thousands still in use in all parts of the country. Even when the bowl of a pan-closet is rilled to the brim and emptied, as in the experiments of Col. Waring for the National Board of Health, by means of a plug, the obstruc- tions to the downfall of the water offered by the sides of the receiver and the inertia of the water standing in the trap, prevent a disturbance at all comparable with that caused by the discharge of powerful flushing closets. The value of a closet as a flushing-tank for the drain pipes is almost exactly proportional to its siphoning power. The investigations of Col. Waring are valuable particularly in showing the siphoning power on branch wastes of the dis- charge of bath-tubs into the main soil pipes, an arrangement extremely common, and in establishing the utmost limit of the siphoning power of the pan-closet, the one then most widely known and used. With the basin filled to the brim and suddenly discharged, the siphonage produced imme- diately broke the seal of unvented S-traps, but could not unseal a vented S. In the experiments of Bowditch and Philbrick a short hopper closet, the next in general use at that time, was employed, and, to secure as useful results as possible, the closet was charged with water from a two-gallon pail, in the manner usually done when it is used as a slop-hopper. Such a use of the short hopper forms a far severer test than its ordinary flushing, though not severer than may often be produced with the powerful flushing of modern fix- tures. More powerful siphoning action is often produced in practice in houses than was given by these tests, and the deductions based upon them which gave rise to the trap- vent law in many cities must be radically changed. For they showed that an S-trap, ventilated as they did it, and subjected to this strain, was secure, whereas a heavier strain 33? Plumbing and Household Sanitation. or a different method of venting may break its seal as I have described. The experiments of Hellyer in England form a better basis for plumbing legislation, inasmuch as his tests were made with those water-closets and other fixtures in com- mon use in England which produce a much severer effect. 338 CHAPTER XXL £^CMLHtJ/H3Z. Fig. 294. Fifteenth Century Lady at Her Toilet from Viollet le Duct Wash Basins. I The wash basins of the ancients were generally double, or provided with pitchers, and this is shown in the sculptures and paintings of -Egypt and in the figures on the bas reliefs and pottery of Grecian antiquity. Figure 294 shows the manner in which these early lava- tories were used. They were quite large and made of sil- ver or copper with pitcher to correspond. They were smooth on the inside so as not to retain dirt or soap, but engraved sometimes very richly on the outside. In use they were placed upon the floor, and the bather was obliged to rest upon the knees, and in this way the basin was used as a bath tub, not only for the head and hands, but for the whole body. I am indebted to the kindness of my friend Prof. Ed- ward S. Morse for permission to reproduce a number of illustrations of Japanese bathing appliances from his most delightful and instructive work entitled "J a P anese Homes and Their Surroundings," in this course. Simple con- fDictionnaire du Mobilier Francais, Vol. Morel, Paris. 2. Published by A. 339 Plumbing and Household Sanitation. veniences exist in Japanese houses for taking a hot or cold bath, as we shall show under Bath Tubs, but wash basins are more primitive. "In the country," says Prof. Morse, "a Japanese may be seen in the yard or by the roadside washing his face in a bucket or shallow tub, and at inns and even in private houses one is given a copper Fig. 296. Japanese Wash Basin.J basin, and, a bucket of water being brought, he uses a por- tion of the verandah as a wash stand." The one shown in Fig. 295 shows how the Japanese of modern times per- petuate mediaeval customs, the shallow trough on the floor corresponding with the carved silver or copper utensils of iFrom "Japanese Homes and Their Surroundings," by Edward S. Morse. 340 Wash Basins. the ancient days. The Japanese lavatory consists of a shal- low trough resting on the floor at the end of the verandah or passageway containing a copper basin and a stout water bucket with cover. 297. Simplicity in Plumbing Appliance? Her Toilet.* Japanese Lady at The bather must crouch upon the ground in order to use this basin, like the people of the past. Another illustration of floor lavatory is shown in Fig. 296. It was placed at the end of the verandah. "A low partition formed a screen at one side; within the recess thus made was a low shelf for the pottery water jar. The •From Japan Tllustre by Aime Humbert Libraire de l'Hachette et Cie, Paris. 1S70. 341 Plumbing and Household Sanitation. floor of the sink consisted of bamboo rods placed close together, through which the spilled water found its way by proper channels to the ground without. A paper lan- tern hung against the wall, and dipper and towel rack were conveniently at hand." The ornamental woodwork in these lavatories is often Fig. 298. Japanese Wash Stand.* very attractive, but the waste water disposal is exceed- ingly primitive and objectionable in every way. It is difficult for us, moreover, to understand how the Japanese find comfort in the cramped position necessary to use these low set wash basins. Fig. 298 shows a form of lavatory more familiar to us. It is a private house in Tokio in a recessed portion of a passageway behind a suite of rooms. Sliding windows with white paper panes admitted light to this most attract- : From Prof. Morse's "Japanese Homes,'" 342 Wash Basins. ive and carefully finished toilet room with its quaint towel rack and neat and simple natural furnishings. The water jar is of rich brown pottery, the dipper of wood and the basin of copper. Prof. Morse says of it: "It may seem odd for one to get enthusiastic over so simple an affair as trough and a few honest contrivances for washing the hands and face ; nevertheless such a plain and sensible arrangement is a relief, in contrast to certain guest cham- bers at home, where one wishing to go through the rather vigorous performance of dashing into the water with his elbows outstretched finds these free movements curtailed to the last degree by a regiment of senseless toilet articles in the shape of attenuated bottles, mugs, soap dishes with rattling covers and diminutive top-heavy pitchers crowded about his wash 'basin, and all resting on a slab of white marble. Things are inevitably broken if they are brought down too hard upon such a bottom. After such recollec- tions, one admires the Japanese sink, with its durable flat- bottomed basin, capacious pottery jar for water, and ample space to thrash about in without fear of spattering the wall paper or smashing a lot of useless toilet articles in the act." This comparison is with our portable basin and pitcher, the neat Japanese wooden sink taking the place of our troublesome and uninviting slop pail with its perforated cover, upon which the tormented bather is expected to guide the waste water from the basin after use with un- erring hand or find half its contents on the carpet. Neither arrangement, however, can compare for a moment with our hygienic and generous city lavoratories, where ample space is provided by a broad slab for free and luxurious bathing, and a judicious arrangement of soap dish and other conveniences on a special shelf above. We must, however, in our cities sacrifice a portion of our thrash- 343 Wash Basins. the waste pipe and trap. The result is imperfect flushing of these pipes and traps, gradual accumulation of filth in Fig. 299. Japanese Towel Racks.* them, and the various serious evils to which such accumula- tions give rise. Not only then should every wash basin be constructed 'From Prof. Morse's "Japanese Homes. 344 Plumbing and Household Sanitation. ing about for the advantages of immediate and convenient removal of the waste water after use by the mere turning of the waste water handle, and thus doing away with the sink or slop pail receiver, which, whether in America or Japan, must retain in its corners more or less sediment from the dirty water discharge, however carefully it is cleansed in the daily rounds of the chambermaid. Fig. 279 shows some of the simple and interesting rus- tic towel racks used by the Japanese. They are made of bamboo and suspended in the various ways shown. "The simplest kind is in the shape of a ring of bamboo sus- pended by a larger bamboo, to the end of which it is at- tached. Another form, and a very common one, is a yoke of bamboo, the lower ends of which are firmly secured to a larger bamboo, confining at the same time a piece of bamboo which slides freely up and down on the yoke, and by its own weight resting on the towel which may be thrown across the lower bamboo. Another form consists of a loop of bamboo suspended to the side of a board which is hung against the wall. "The towels are pretty objects, being of cotton or linen, and usually have printed upon them sketchy designs in two shades of blue." Coming now from the appliances of other times and people to our own requirements, we find the form and construction of our lavatories a matter of much greater importance than is generally supposed. We are to abolish trap venting and obtain the cleansing of our branch waste pipe system through water flushing. All our plumb- ing fixtures must therefore be constructed on the principle of the flush tank ; that is, they must have discharge outlets as large in their clear waterway as the waste pipes to which they are connected. As usually constructed, the outlets are still altogether too small in proportion to the size of 345 Plumbing and Household Sanitation. on the principle of the flush tank, but it should be so con- structed as to encourage its actual use as such, or, in other words, so as to render it more convenient to use it properly as a flushing apparatus than improperly as a simple open funnel to guide the water, used running from the faucet into the waste pipe. Both economy and safety as well as convenience are dependent upon such construction. It will be found on accurately measuring the clear water- way in the outlets of the majority of lavatories now in use that when the space and function of the strainer are con- sidered, the efficiency of the flush is very greatly reduced, and with all lavatories of the older styles having the con- ventional forms of basin and sink strainers the amount of waterway is not more than equal to that of a J4~inch pipe. A very short usage soon reduces this meagre opening, through the collection of sediment and lint, to a still smaller stream. The waste pipes are usually ij4 to 13/2 inches in diameter, a capacity which is given for the purpose of ensuring the safe removal of the water delivered by two supply faucets running full force, under medium or high city pressure, and escaping through the outlet and overflow passages combined, together with a possible simultaneous discharge of other adjoining fixtures entering the same waste. Now a half or three-quarter-inch stream of waste water trickling through pipes capable of delivering many times as much, fouls but does not scour them. I have taken out such waste pipes and found them more than half filled with slime and filth, and in places where the pipe ran nearly horizontal, or made sharp bends, I have found them nearly filled with the putrefying mass. No amount of ven- tilation can cleanse such pipes. But the sediment was soft and gelatinous, and would easily have been swept away by the powerful discharge of a basin filling the pipes "full bore." 346 Wash Basins. As already described, I caused a piece of waste pipe in which coating of sediment had been collecting for a long time to be flushed by a wash basin constructed with a large outlet after removing the plug and chain basin through the use of which the sediment had been deposited. From the new basin the water rushed at the rate of about half a gal- lon a second. After two or three discharges it was found that almost all of the coating of greasy sediment and slime had been removed by the powerful friction of the water. It must be borne in mind that the scouring effect of a stream of water (irrespective of its size) which fills the waste pipe "full bore" is entirely different from that which only partially fills it. The former flows with a velocity and force determined by the weight of its entire column, or under a head equal to its perpendicular length; while the latter falls without head, because the air breaks the continuity of the Vvater column, and then the velocity and force occasioned by the head is entirely destroyed. Now, with a very small flushing stream an S-trap be- comes equivalent to a pot trap, and its fouling tendency is as great as a pot trap having a waterway bearing the same proportion to the size of its body that the contracted basin outlet bears to the body of the S-trap, and the same holds even with a straight waste pipe itself. As the first aim and principle of sanitary engineering is to remove foul matters as rapidly and completely as pos- sible, so, in the present connection, our first care should be to see that our fixtures are formed with outlets large enough to fill the pipes full bore in order to accomplish this result. Had the framers of our present plumbing laws included a provision requiring a ll lavatories to be constructed on this principle, instead of insisting upon the worse than use- less trap and branch waste ventilation, the public would 347 Plumbing and Household Sanitation. have been benefited in many more ways than one. No reason is given why the laws should now continue to exist with these serious imperfections, and no good reason can be given. It remains to be seen how soon the good sense of the public will demand their correction. Besides the important sanitary advantage of a rapid discharge, we have others of economy and convenience. To empty an ordinary basin with contracted outlet re- quires a very considerable amount of time and patience. The result is that people fall into the habit of washing from the faucet rather than from the basin, and a great waste of water is involved. A quick wasteland convenient method of operating and controlling it results in a saving of water and very great convenience in usage. A knowledge that a sudden discharge of a basinful of water through the pipes acts as an important sanitary measure, after the man- ner of a flushing tank, in cleansing them from end to end, leads to a legitimate use of the basin, and an economy of water, a consideration which the public in times of droughts will not be slow to appreciate. A critical examination of the leading types of fixtures now in use is necessary to enable us to understand clearly what features are to be recommended, and what are to be avoided. Such a classification is also indispensable to enable us to judge at once for ourselves the merits of any fixture we may be called upon to examine. It systematizes our ideas, and in this lies its chief difference from a mere "cataloguing" of plumbers' supplies, which oftener results in confusion. From these considerations it is evident that our drawings must illustrate, not imaginary types, but those in actual use, in order to be of any practical benefit as a guide in selection, and hence we shall in most cases select some special fixture as a standard representing its class. 348 Wash Basins. Classification of Requirements for Basins. The ideal wash-basin should possess the following char- acteristics : ( i ) It should be so formed as to permit of a discharge rapid enough to fill the waste pipe "full bore." (2) It should have a suitable overflow without con- cealed or inaccessible passage. (3) The whole of the fixture and all of its parts should be easily accessible at all times. (4) Its outlet passage should be controlled by a mech- anism requiring but a single, simple movement to operate it, and the minimum of strength or effort. (5) It should be easy to set, and have no parts liable to clog or get out of order. (6) Its outlet mechanism should be so constructed as to require no fitting or adjusting. (7) It should have a minimum of surface exposed to the water used. (8) It should be simple, durable, economical and pleas- ing in appearance. 349 CHAPTER XXII. Classification of the Different Kinds of Basins. I have divided basins into two general classes : ( i ) Those having concealed over- flow passages, and (2) those having open overflow passages. Each of these is subdivided as follows : Basins having concealed over- flows into: Fig. 301. Ordinary Wash Basin with Plug and Chain Outlet. (a) Plug-and-chain outlet. (b) Waste-cock outlet. (c) Valve outlet. (d) Plunger outlet. (e) Floating-plug outlet. (f) Standpipe outlet. (g) Receiver outlet. Basins having open overflows into: (a) Funnel outlet. (b) Standpipe outlet. (c) Rear outlet. Each of the above classes may have for its supply either ordinary standing faucets or nozzles supplying water at some point or points below the basin rim. 350 Classification of the Different Kinds of Basins. I. — Concealed Overflow Basins. This class of fixture violates one of the first conditions of sanitary plumbing. A portion of the apparatus intended to carry off waste water at irregular and uncertain inter- vals, by which it becomes fouled without the possibility of Fig. 302. Section of an All Porcelain Plug and Chain Basin. Fig. 303. Section of Plug and Chain Basin with Overflow Passage Cast with the Basin in One Piece. cleansing through water flushing action, is placed in such a position that it cannot be seen nor reached without discon- necting the whole fixture. Our first subdivision of this class is the ordinary (a) Plug and Chain Outlet Basin. We see here (Fig. 301) a concealed overflow pipe con- 351 Plumbing and Household Sanitation. structed of lead and so placed as to be altogether inacces- sible. Being above in open communication with the air of the room, it taints it with the decomposing soap and filth with which its sides soon become coated, and this odor and the fear of sewer gas leads to the common practice among house owners of stopping up the holes in the earthenware leading into the overflow pipe at considerable inconvenience to themselves and increase in siphoning action upon traps below. Fig. 303 bis. The ordinary wash-basin has no proper flange for con- nection with the lead overthrow pipe, and the joint in the majority of cases is not a reliable one at this point. The connection of the lead overflow pipe with the waste pipe must be made above the trap, and must be wiped with solder, so that two joints are necessitated at the overflow, which add both to the expense of the work and to the chances of imperfection and leakage. It is an exceedingly common thing to find the overflow pipe wrongly connected. 352 Plug and Chain Basins. It is sometimes entered below the trap, sometimes attached directly to the trap vent, and sometimes connected with the wastes of other fixtures in such a way as to open through the vent pipes an indirect avenue into the house for sewer air, as we have shown in our illustrations of "by-passes." It forms, in short, an unnecessary and dangerous com- plication to the plumbing, which more than offsets any slight saving in the first cost of these cheap fixtures, and they should never be used. The plug and chain feature which characterizes this type of basin is another defect. The chain, lying in every suc- Fig. 304. All Porcelain Plug and Chain Basin. cessive formation of dirty water, collects gradually in the recesses of its links an unknown variety of filth, which can- not be absolutely removed, on account of its irregular form, without the use of special alkalies, or constant scrubbing with a brush, a process I have never seen applied to it effect- ively. The length of wire used in an ordinary basin chain averages six feet, and has a surface of about fourteen square inches, a surface which, in consideration of the pe- culiar adaptability of the form of the links for retaining dirt presents a very formidable area of pollution.* To those persons who use their reasoning powers in these matters, the idea of washing the face in water defiled by a chain transferred immediately from the dirty water of some un- *A chain of average cleanness might easily contain more than at grain of dirt unnoticed in its links, which bacteriologists have shown may contain over a million bacteria. 353 Plumbing and Household Sanitation. known predecessor is with good reason exceedingly repul- sive, and when the nature of disease germs in water before it reaches the sewer are considered the danger of contagoin where the predecessor may have chanced to be a sufferer from skin or other contagious disease the feeling of repul- sion is justly increased. The chain, moreover, frequently breaks, and then the hand must be plunged into dirty water to remove the plug. The position of the chain and plug at the bottom of the bowl is peculiarly inconvenient, inas- much as they are in the way of the hands, which ought to Fig. 305. All Porcelain Plug- and Chain Basin. meet a smooth, unbroken surface of earthenware, rather than the hard and irregular lines of the brasswork. If this latter consideration appears to some trivial, it does so only' because custom has rendered us callous to such defects ; the defect none the less exists, and acquires importance through the frequency of its repetition and the constant use of the fixture in which it occurs. The fact that it is alto- gether unnecessary, either for economy or for any other reason, is a sufficient argument for its abolition. Thus we find none of the eight desiderata enumerated in our table of requirements that the wash-basin, still in most common use, possesses. 354 Plug and Chain Basins. Figures 302, 303, 304 and 305 represent in section and in perspective all-porcelain plug and chain basins. Figs. 302, 303, 304 and 305. Figure 306 represents a plug and chain basin with a flushing rim supply. The disadvantages of this arrange- ment are quite as great as the advantages. Water cannot be drawn into a separate vessel from this form of supply, and this is often quite important. Moreover, the flushing rim greatly increases the cost of the fixture. The object Fig. 306. Plug and Chain Basin with a Flushing Rim Supply. of the flushing rim is to cause a partial cleansing of the sides of the basin by the running water before filling. Constructing the overflow pipe in one piece with the basin, as shown in Figs. 302 to 305, gives a great advantage. The danger of defective overflow connections is thus avoided, and the setting of the basin is very much easier. A closure of the overflow holes of this basin affords an actual tem- porary safeguard against the evils arising from evaporation 355 Plumbing and Household Sanitation. of the water seal caused by trap ventilation, where a fixture is left unused for any length of time, provided the outlet be also tightly closed and both closures be closely watched. But in this case the danger of damage from overflow ap- pears. Figure 307 represents a basin with a plug and stem outlet, the earliest form constructed by the writer. Fig. 307. Basin with a Plug and Stem Outlet. (b) Waste Cock Outlet. Here the outlet passageway is controlled by an ordinary ground brass water-cock. The general type may be further subdivided into three kinds : ( 1 ) Those having perpendicular waste-cock moved by a rod passing through the marble slab; (2) those having a horizontal waste-cock worked from the front of the stand below the bowl ; and (3) those in which the waste- cock is operated by a lever movement. As an illustration of the first kind we have the so-called "Boston Waste," Fig. 308, which is very popular. There is probably no form of basin fitting more faulty in principle than this. It contains two independent, inaccessible and invisible foul water passages, one forming the overflow 356 Waste Cock Outlet Basins. passage, and the other the outlet passageway between the strainer and the waste-cock. This latter passage forms an elongated cesspool for the defilement of the clean water entering the basin. After using the fixture, the waste water escaping through this channel deposits part of its dirt, particularly floating mat- ters and soapsuds, all along its sides, and leaves it there to be taken up and applied in a diluted solution to the hands Fig. 308. Waste-Cock Outlet Basin, the "Boston Waste." and face of the next comer. Six wiped solder joints, one putty joint and five threaded joints, making twelve in all, are required to adjust the waste pipes of the regular Bos- ton Waste apparatus and its trap below the basin slab can- not be relied upon as a sure seal at all times against sewer gas, because we cannot depend upon its always being turned off after use, this device becomes valueless. No wonder the plumber is often in requisition to keep in 357 Plumbing and Household Sanitation. order such complicated machines so long as they are al- lowed to remain in use. Not the least of its defects is that the passageway for the waste water through the ground Fig. 309. The Waste-Cock Outlet Basin with Syphon Overflow. Fig. 310. Waste-Cock Outlet Basin with Horizontal Plug. cock is usually so small (about a quarter of an inch wide in some types) that the least deposit of sediment is liable to radically impede this meagre flow. 358 Waste Cock Outlet Basins. The "Boston Waste" cannot be too highly condemned and should be prohibited in all plumbing ordinances, as should all restricted outlet basins, because with these al- lowed, no proper sewerage system can ever be attained. The great extent of the use of fixtures constructed on the principle of the "Boston Waste," in spite of its high cost, shows how little knowledge the public has in these matters, and how important it is that their attention should be called to them. In Fig. 309 we have the Boston Waste complicated with still another disorder. The overflow pipe, instead of open- ing into the upper part of the basin, descends and re-en- ters the waste pipe on the inner side of the waste cock. This doubles the length of the inaccessible cesspool be- tween the outlet and the waste-cock. Its object was ap- parently to trap the overflow pipe ; but as the waste-cock cannot be relied upon as a sure seal at all times against sewer-gas, because we cannot depend upon its always being turned off after use, this device becomes valueless. Figure 310 represents the second kind of waste-cock out- let basin in which the waste-cock is horizontal, and oper- ated through the riser or woodwork of the washstand. This arrangement necessitates encasing the basin to some extent in finish, a requirement which adds another to its many dis- advantages. In other respects it is similar to the "Boston Waste" already described. Figure 311 illustrates by a special apparatus, possibly never executed in its entire perfection, the third kind of waste-cock outlet basin. The fixture shown is an English invention devised by some one who had seen Mr. Bunyon's sewer already described. It is useful to illustrate the evils of over-complication. The machinery is moved by cranks and levers connected with a pedal in front of the stand. How the inventor could have imagined anyone would be 359 Plumbing and Household Sanitation. tJt Fig. 311. Waste-Cock Outlet Basin with Lever Movements. 360 Waste Cock Outlet Basins. found willing to pay for so complicated a piece of brass- work is difficult to understand. In the device a lid is em- ployed to cover the basin when it is not in use, and there is a thick rubber gasket not quite so large and costly as an automobile tire around the basn to form a sewer gas tight packed joint with the lid which is held pressed against the packing when closed by a strong spring. Two waste-cocks, one for the main outlet, and the other for the overflow, and one or more supply cocks are used, and these cocks are connected with the lid in such a manner that, when the lid is raised or lowered, the supply and waste- cocks are respectively opened and shut. The waste-cock thus does not serve as a seal against sewer gas, and a sepa- rate trap, not however shown, would be necessary. The lid mechanism would require the strength of a stone crusher to operate this net work of valves and levers even when new, and it never seems to have occurred to the inventor that dirty water would soon take away what little mobility they might have in the beginning. 361 CHAPTER XXIII. (c) Valve Outlet Basin. I Our next type of wash-basin corre- ff\ f^f' s P on ds in principle with the valve water T'r ^H/jjJ closet. The outlet is closed by a valve V working in a small chamber or receiver, I which, like the water closet receiver, is I liable to become clogged with sediment. I Moreover, the concealed machinery neces- *jj sary to work the valve complicates the ap- L! paratus, and like all machinery, especially "Perfected" Fr p>ath that which works under dirty water, is Room Apparatus.* Hable tQ get QUt of Qrden We have further subdivided this type into three kinds, i. e., those with (i) chain movement; (2) lever movement, and (3) gravity movement. Figure 312 illustrates the first kind. We have here two elongated cesspools and a receiver cesspool. No overflow passage is shown in this drawing, though provision for overflow is of course as necessary as in any of the preced- ing examples. A valve arranged as shown here would never work sat- isfactorily. The slightest impurity adhering to it or its seat would cause it to leak, and a little roughness or cor- rosion on the hinge might prevent its closing altogether. Figure 313 represents a valve outlet basin operated by lever movement. The drawing shows a double bottom, the ♦Portable wash basin over fixed bath tub, from Joly, chapter headed "Appareils Economiques Perfectionnes." From the Amer- ican point of view, the arrangement, especially the trapping, does not seem quite "perfect." 362 Fig. 312. Valve-Outlet Basin with Chain Movement. Fig. 313. Valve-Outlet Basin with Lever Movement. 363 Plumbing and Household Sanitation upper one being perforated throughout its entire extent, and forming an enormous strainer. The valve receiver oc- cupies the whole space between the two basins. The amount of inaccessible fouling space is here very large and of pecu- liarly objectionable form, the many perforations and corners being calculated to retain a great deal of filth. The waste water escaping through so many holes would pass without force or scouring effect, and the cleansing of such a strainer Fig-. 314. Valve-Outlet Basin with Outlet Supply. would be practically an impossibility. Some overflow pas- sage, not shown on the drawing, would be required. Figure 314 shows a basin of the same kind with a smaller receiver. The supply enters below the strainer, which is evidently objectionable for several reasons. In case of fluc- tuation in the water supply pressure, foul water might be drawn from the basin into the supply pipes. Moreover, the dirty deposits in the valve receiver would always be mixed vvith the first clean water entering the basin. 364 Valve Outlet Basin. Fig. 315. Valve-Outlet Basin with Improved Lever Movement Fig. 316. Fig. 317. 365 Fig. 320. 366 Fig. 322. Fig. 324. Fie. 325. Fig. 326. 367 Plumbing and Household Sanitation. Figure 315 shows an improvement on the last device because the receiver above the valve is eliminated alto- gether. Figures 316 and 317 give the third subdivision of our valve outlet basin, namely, that in which the valve is oper- ated by the weight of the water falling upon it. Comment on such a device is scarcely necessary, it being sufficiently evident that its action would be extremely unreliable and unsatisfactory. The valve is made flat or cupped on its upper surface. In the latter case water held in the cavity of the valve is supposed to assist in forming a seal. Figures 318 to 326 represent other forms of Valve Outlet Basin, all to be recommended for their simplicity, large out- lets and cleanliness, there being no fouling chambers at the outlet. Where the overflow passages are accessible for cleansing, these fixtures are in all respects excellent. 368 CHAPTER XXIV. (d) Plunger Outlet Basin. Our plunger outlet basin corresponds with the plunger outlet water closet, and has its defects. A great defect is its sev- eral inaccessible fouling chambers. The type may be subdivided into two styles, namely: (i) That having a solid plunger, and (2) that having a hollow plunger. Figure 327 represents the first style. The plunger is supposed to retain the water in the basin by the friction of a packing ring of some elastic material against the inner Fig. 333. walls of the plunger chamber. A D-trap appropriately used under the plunger completes a device which, for extent of fouling surface, cannot easily be sur- passed. Fig. 328 is an improvement on the last type. There are less fouling surfaces and the outlet passages are made of smooth earthenware. The plunger chamber is made ac- cessible by unscrewing the plate at its top, and the horizontal channel below the strainer is the only part that cannot be reached. Figure 329 is a still further improvement, inasmuch as the horizontal chamber is done away with by having a per- pendicular back to the bowl. The overflow passage is faulty. It should have been constructed after the principle of the preceding fixture, or better still, in the form of a simple standpipe on the plunger. The chief defect, however, is in having the clean water come in contact with the fouled sur- 369 Plumbing and Household Sanitation. face of the plunger chamber. The valve should always be placed directly at the outlet opening to avoid this defect. Figr. 32 S Figure 330 represents the second style of plunger out- let basin in which the plunger is hollow. We have, how- ever, here again the favorite cesspool triply emphasized. 370 Plunger Outlet Basin. Fig. 329. Fig. 330. (e) Floating Plug Outlet Basin. The object of this device, Figs. 331 and 332, is to do away with the special overflow opening in the basin 371 Plumbing and Household Sanitation. Pig. 331. Fig walls. The plunger or plug has a hollow vessel at the upper end of its stem, and the receiver is enlarged at this point to give room for it. When the water in the basin approaches 372 Plunger Outlet Basin. the point of overflowing, the plunger is buoyed up by the float (the water seeking its level in the plunger and float Plumbing and Household Sanitation. chamber), and the outlet is opened, letting the superfluous water in the basin escape. (f) Concealed Standpipe Outlet Basin. The object of this arrangement is the same as the float- Concealed Standpipe Outlet Basin. ing plug in the preceding apparatus. It enables the spe- cial overflow opening to be dispensed with, the hollow plun- ger rod serving instead. Figs. 334 to 336 show the stand- pipe as constructed with a metallic chamber. Fig. 337. Plumbing and Household Sanitation. Figure 337 shows a concealed standpipe outlet basin made in all earthenware. Figure 338 is a very complicated form of concealed stand- pipe Outlet Basin with an enormous amount of fouling surface. (g) Receiver Outlet Basin. The principal object of this device is to obtain a quick discharge. It consists of two basins, one within the other, the inner one pivoted, as shown in Fig. 339, in such a man- ner as to permit it to be revolved by means of a projection on the front edge, raising which empties the entire contents of the basin into a lower basin or receiver. Only half of the receiver is accessible, hence it inevitably becomes foul in use. Fig. 339. Receiver Outlet Basin. 376 Plunger Outlet Basin. II. — Basins Having Accessible Overflow Passages. In this class of fixture every part, both of the basin proper and of its fittings and passages, is visible and easily accessible, and kept clean from top to bottom without un- screwing or undoing any part. We find three subdivisions : (a) the funnel outlet basin; (b) the standpipe outlet basin, and (c) the rear outlet basin. (a) The Funnel Outlet Basin. Figure 340 illustrates our first subdivision. In general form it is similar to the one just described, but it has the Fig. 340. Funnel Outlet Basin. advantage of enabling the entire surface of the lower basin to be reached for cleansing purposes. The interior of the outlet pipe may be inspected and, if desired, periodically cleansed throughout. It is intended that the upper basin should be lifted after use, and the waste water emptied 377 Plumbing and Household Sanitation. into the lower basin or funnel. In case of overflow, the water runs over the edge of the upper basin and falls into the lower, whence it escapes into the waste pipe. It is evident that to avoid the trouble of lifting the basin it may be provided with lugs or pivots upon which it may be re- volved as in the preceding example. Both of these types are altogether faulty in being based on the receiver principle, which also adds greatly to the cost and danger of breaking. The receiver is an entirely unnecessary complication, and the basin has never been largely used in practice except in marine service. Basins are sometimes provided with a flusning nozzle for connection with the water supply. The flushing device is added to insure a perfectly clean overflow passage when- ever the owner sees fit to operate it. A leakage of water- cock at this point would give rise to an unperceived waste of water. This fixture is constructed with a large outlet on the principle of the flush tank, and is in this respect highly to be commended. (e) The Rear Outlet Basin. The basin answering all the desiderata I have enumer- ated at the beginning of this lecture should have an out- let larger than its waste pipe and conveniently operated within the basin itself. It should be absolutely simple, hav- ing neither niche, chain nor standpipe, and its overflow pas- sage should be as clean and accessible as any other part of the fixture. 378 CHAPTER XXV. (b) Standpipe Overflow Basin and (c) Direct Outlet Basin. Before 1883 lavatories were made, as a rule, with concealed overflows, strangely enough, and open standpipe overflow basins had not been intro- duced. The first basin of this kind was beaten out in the winter of that year, 1883, of sheet lead after the writer's drawings and afterwards moulded in a local terra cotta yard in yellow clay and baked, and the name "Sanitas"' was given to this new type. Mr. Gerhard, in one of his European treaties on Plumb- ing,* writes of it in 1897 as follows : "The prototype of all basins of this construction is the "Sanitas" wash basin, invented several years ago by the Boston architect, Putnam, which is shown in plan and trans- verse section in Fig. 341, and in perspective in Figs. 342, First Rear Outlet. Lavatories and their Early Setting. "Entwasserungs-Anlagen Amerikanischer Gebaude von Win. Paul Gerhard, Civil and Sanitary Engineer in New York, in Fortschritte auf dem Gebiete der Architektur. Stuttgart 1897. Vejiag von Arnold Bergstrasser." 379 Plumbing and Household Sanitation. 343.** This device is in many respects fundamentally dif- ferent from the kinds of basins hitherto described, and is distinguished by the advantage of having a simple, con- venient and sanitary construction. The basin is made either round or elliptical, and has at its back a niche or recess, in which is placed in clear and open view a standpipe valve. Fig. 341. As this serves at the same time as an overflow pipe, we have in it a new form of overflow construction for basins. All parts of the basin and its fittings are in sight and easily accessible, and it contains no concealed chamber or parts of **The Figures in Mr. Gerhard's treatise give other views of the Sanitas basin. 380 Standpipe Overflow and Direct Outlet Basins. any kind, as is the case with many of the basins of other styles for the collection of sediment. The overflow pipe is made detachable, but can nevertheless be easily cleaned with- out removal." Mr. Gerhard then describes the appliance in detail and concludes as follows: "The many acknowledged advantages of the 'Sanitas' basin produced the result that a great number of basins of similar construction were put upon the market. Nevertheless, in spite of all the recog- nized advantages of this kind of basin, the American public were fond of the concealed overflow type, and even the recommendations of the leading sanitary engineers have not Fig. 343. as yet succeeded in bringing this type of basin into univer- sal use." Again, in "Good Housekeeping," Mr. Gerhard writes in 1886 : "Much the best form of basin of which I have knowl- edge is the standpipe outlet basin or Sanitas' wash basin." 381 Plumbing and Household Sanitation. After a description of the basin he continues : "It is thus seen that the great desideratum, that the fixture should act as a flush tank for its waste pipe and trap, is here accom- plished," etc. Fig. 344 shows one of the earliest forms of the Sanitas Lift There are a number of better basins than this on the market today, and Mr. Gerhard would probably now be unable to give this one such high recommendation. Since the year he wrote, many other basins have been built with Standpipe Overflow and Direct Outlet Basins. large outlets capable of performing the work of the flush tank and many in which all cesspool chambers have been avoided, as in the excellent types shown in Figs. 317 to 326, inclusive, which in reality leave little to be desired in es- sentials. Fig. 345 shows a somewhat more complicated form of standpipe overflow basin which appeared later. It has a regular automatic flush pot discharge. The standpipe overflow type of basin has the disadvan- tage of presenting a certain amount of surface exposed to the washing water beyond what is absolutely necessary. A still further improvement is possible in which even greater simplicity is attained without sacrifice of any val- uable feature. Figs. 346 to 361 show a number of the writer's designs. The exterior surfaces of both the stand- Fi^. 346. Fig. 347. pipe and of its niche are done away with, while equal ac- cessibility of all parts is still preserved as in some of the types described. The standpipe overflow is simply molded in with the rear of the fixture as a fixed part of it and the discharge is effected not by lifting the standpipe but by operating a valve of proper construction within it. This valve should stand directly against the Outlet opening in the wall of the fixture, as shown in these figures, so 383 Plumbing and Household Sanitation. that there be absolutely no unnecessary amount of surface in the interior of the fixture, and the whole valve as well as the interior of the overflow passage should be easily accessible for cleansing. Fig. 350. Fig-. 351. Fig". 352. 384 Standpipe Overflow and Direct Outlet Basins. The mechanism for controlling the valve should be simple and its operation self-explanatory to the user. Where the fixture is intended for use in public places the construction shown in Figs. 346 to 353 renders it im- Fig. 353. possible for anyone to remove and carry off the operating brass work. The drawings explain the manner in which this is done in this instance. For private houses the still simpler mechanism of Fig- ures 346 and 347 suffices. The ground plug is easily lifted out for cleaning the overflow passage. The end of the handle has a downward curve which suggests and aids in slightly lifting it for easier turning, and the movement Tig*. n 9 2. FigS. Fig. 356. Fig. 357. 385 Fig. 358. Plumbing and Household Sanitation. is so easy that a light touch of the finger is sufficient to open or shut the outlet. Fig. 359. Fig. 360. Fig. 361. It is better to construct the entire fixture of hard earthen- ware or enameled iron and in one piece, as is now custom- ary, because the whole fixture is stronger, easier to sup- port, cheaper and better than the comparatively old-fash- ioned combination of earthenware and marble put to- gether with plaster and supported on metallic legs or brackets. The use of the enameled iron construction for the entire future and its outlet passages insures safety against a possible fracture of the material of the outlet by a sudden expansion of the metallic waste valve work when very hot water is used. This is a consideration of importance. All that is needed to support the fixture is a few screws driven into the bathroom wall through holes in the back of the fixture, no special legs or brackets being required. Fig. 363 shows the section of the outlet mechanism for a fix- ture so constructed. Figs 356 to 361 give other simple forms of the writer's valve outlet basins, illustrating the principle of a valve operating directly at the basin outlet by a very simple mechanism which sufficiently explains itself. THE SECURITAS BASIN. Figures 362 to 365 illustrate the writer's latest improve- ment in basins' to which he has given the name "Securitas,"- for the reason that it provides, in the simplest manner, abso- 386 Standpipe Overflow and Direct Outlet Basins. lute sanitary security against contamination of the clean water by any concealed or inaccessible parts, and at the same time by virtue of having no projections, recesses, irregular- ities or roughnesses in any part of its contour, it provides entire security against inconvenience or mechanical injury in use. Fig. 362. Fig. 363. The peculiarly simple working parts being constructed almost entirely of white enameled iron there is nothing to require refinishing and nothing of intrinsic value to tempt the honesty of thieves or vandals in public places. There- fore virtue is promoted as well as comfort and art. The shining white surface of the operating mechanism 387 Plumbing and Household Sanitation. harmonizes with the color and texture of the fixture itselt and presents with it a very attractive appearance. When the same white enamel is used also in the trap as shown in Fig. 365 the effect is still more striking and attractive. The whole outfit has then always, after any length of usage, the Fig:. 364 same perfectly clean and bright appearance as it had the day it was first installed. Figs. 364, 365 and 366 give perspective views of the device, and Figs. 362 and 363 sections showing details pi its Waste Outlet Mechanism. The movable standpipe over- flow and its niche are done away with, and a single over- flow and outlet passage, easily accessible and convenient for cleansing without presenting any fouling surface to the clean water, takes its place. The interior of the basin is entirely unobstructed, no 388 Standpipe Overflow and Direct Outlet Basins. brass work or projection of any kind being in the way of the user. The valve stem, also of enameled iron, is made adjustable as shown, and is operated by a simple enameled iron lifting device sufficiently explained by the drawings. The handle consists of a small sphere connected by a yoke with a lever Fig. 365. within a larger sphere, and the lever directly actuates the valve in the manner shown. The weight of the handle and its leverage aid the weight of the valve and its stem in forc- 389 I Pig. 365a. "Securitas" Wash Basin and White Enameled Trap. Re- arranged from Catalog by Courtesy of Federal -Huber Co., N. Y. 390 Standpipe Overflow and Direct Outlet Basins. ing the soft valve packing tightly against its sect. When open the handle stands at the dead point directly above its pivot in line with the valve so that the valve cannot acci- dentally close, and yet a touch in the right direction is all that is necessary to cause it to close automatically and noise- lessly. The form immediately suggests the correct method of operation, so that a course of lessons in handling is not required. The valve packing consists of a simple soft rubber ring sprung around the valve in a groove provided for it. The whole mechanism provides the maximum of strength and convenience with the minimum of expense and complication. The operating mechanism is easily removed for cleansing the outlet chamber by simply lifting it up against the slight pressure of the four small springs in their slots. It is re- placed by a corresponding reversed pressure. The springs are strong enough to prevent all rattle in use, but afford but very feeble resistance to removal, a slight side pressure re- moving two of the springs at a time. This method of re- moval might be too easy were the parts constructed of brass or other metal of intrinsic value for the reason already given. But with enameled iron having no selling or pawning value, there is no object in requiring a complicated or incon- venient method of taking apart. Hence the economy of the device provides a special feature of convenience to the user beyond its usual advantage to the pocket. The valve is guided to its seat by the two small sidehorns cast on its outer rim engaging in corresponding side grooves molded in the pottery as shown. In virtue of this arrangement the valve cannot possibly be inserted in any other than its right place, and the whole device becomes automatic and fool proof. The stem having been once adjusted by the manufacturer or plumber to the 391 Plumbing and Household Sanitation. depth of the basin, there is nothing further to be done by anybody, no screws, or nuts to be removed or replaced in usage or cleaning, no rods or levers to be manipulated, and no standpipe, stopper, chain, or other obstruction to try the user's patience. The overflow passage is made large enough to admit the hand for easy and thorough cleaning. Thus all the requirements mentioned as necessary to pro- duce our ideal basin seem herein to be fulfilled. Ti g .365b. Fig. 365c Tig. 365,1. 392 CHAPTER XXVI. Kitchen Pantry Sinks and Baths. Of all plumbing fixtures none are more dependent upon a proper form of discharge than those into which grease and organic refuse coming from dish washing are brought. No- where is the application of the principle of the flush tank more needed than here, because in no other manner than by thorough intermit- tent flushing can the greasy matters passing through them be disposed of without rapid clogging of the waste pipes. To remove these matters from the dishes used in cooking and serving food hot water is necessary, and this liquefies the grease. If the volume of water into which this melted grease is led is not sufficient to partially congeal it and carry it through the waste pipes with a powerful rush, it will congeal upon and putrefy in these pipes until a seri- ous nuisance is formed. In ordinary sinks in general use, the melted grease dribbles through the sink strainer and chills upon the inside of the waste pipe and in the mouth of the vent pipe and all other corners of the trap before it has traveled a rod from the sink. In chilling, it forms a coating in these places so hard that it is subsequently often very difficult to remove, and soon causes annoying stop- Fig. .°>06. An Ancient Painting of a Roman Bath, from Joly. 393 Plumbing and Household Sanitation. pages. The obstructions can sometimes, but not always, be removed by pouring a hot solution of potash into the pipes until the grease dissolves and becomes converted into soap. When proper cleanout caps have been arranged in the sink waste pipes, an obstruction can sometimes be reached and scraped out by proper tools ; but such opportune open- ings are seldom found when and where needed, and the removal of this putrid matter is, at best, so exceedingly of- fensive and unwholesome an operation that it is usually de- ferred so long as possible, and the foul putrefaction goes on in the waste pipes out of sight. Fig. 366a. Col. Waring's Flush-pot Sink. The late Col. Waring was, I believe, the first to call at- tention to the need of constructing sinks on the principle of a powerful flushng tank, and he invented a sink which I have reproduced in section in Fig. 366a. It consists of a large flush pot which can be attached to a sink of any kind. Col. Waring describes it as follows: "The flush pot is an entirely new departure. It holds back everything, water and all, until it is filled. The pot under the sink holds six or seven gallons. Its contents are then discharged — the whole 394 Kitchen Pantry Sinks and Baths. volume suddenly — with such scouring force as to prevent adhesion to the walls of the waste pipe. It is entirely simple in its construction and needs no special thought. When the water ceases to run from the sink, the cook knows that she must lift the plug of the flush pot. The strainer may easily be removed at will. The whole interior, then exposed to view, is within easy reach of a cloth, so that it may be kept as clean as a soup kettle. We thus secure the entire removal of the whole of this greatest source of foul decomposition before its putrefaction begins. In discharging the flush pot, the handle should be raised only until the stop strikes the lower side of the strainer. The strainer should not be re- moved except for cleansing. It should never be removed while refuse of any kind is in the sink." Unfortunately the average cook is neither a philosopher nor a sanitarian, nor does she disturb herself about the dis- tinction between the friendly bacteria of decomposition and the criminal classes of putrefaction, and she does not care about the bacteriological and chemical constitution of the air of sewers. Consequently she is too apt to forget all about operating the outlet plug, and there have been instances where this has led to a disastrous overflow of dirty water over the floor, and to a simultaneous outburst of language of similar complexion from the irate cook, followed by an un- ceremonious discharge by her of the Colonel's offending plug and its consignment for good and all to the demnition bow- wows. She also takes this occasion to eulogize unconscious- ly the famous sanitary engineer and author of this device as she wonders how anyone could ever have been such a fool as to plug up a sink outlet, which of all places should be left wide open for the "instant and complete removal of waste matters into the drains as soon as they are formed," and to add insult to injury she lifts out the Colonel's strainer and brushes into the capacious flush pot all solid matters 395 Plumbing and Household Sanitation. too coarse to pass through the strainer, seeing that the flush pot outlet has been kindly made large enough to save her all the trouble of removing them from the sink by hand. The sink shown on Figs. 366b and 366c is one devised by Mr. Gerhard. It is divided by a perforated partition wall forming a strainer into two parts, a shallow and a deep part. V,VrrVrV,VryrrrVrVrVrVS ahclch of A ^loupdupg Ovef-low fyfcljei? flus^c] A.ppc-»f-<3.lus. Fig. 366b. , poooooooa 1O000O0001 pOOO OOOOQ ,Oo» 00 o, boooooooo 'OOoOOOOO' booo 00000 ;p»*> / Fig. 366c. The shallow part is used in the same manner as an ordinary sink. When the deep part is filled to the overflow line of the standpipe it can be discharged as a flush pot by lifting the standpipe. This part of the sink serves the further use- ful purpose of enabling dishes, pots, etc., too large for con- venient handling in the shallow dish to be effectively washed in the deep body of water furnished by the flush pot. 396 Kitchen Pantry Sinks and Baths. The chief difficulty in the mechanism of each of these devices is that they are not automatic in action and the users will not take the trouble required to operate them properly. They will not hold up the plug or standpipe while the water is escaping. There is too much work to be done elsewhere, and it is too easy to simply remove the plug or standpipe and let the water take care of itself. We must recognize this creditable desire of cooks and pantry maids Fig. 366d. First Automatic Flushing Sink. © e o o « c e e o o © e '\ eeeeecoeee © © ooocceoeee © © e e e «*o o e © e o © c oeeeeccoeee « _ « e o o e e e e t e • • O e e o • © © c oeoeceeco© o o 6oee©«e»ee © © ©oo©o©©©©© © t> eoooeooeea o • , Ooeeoooe © « o -; Fig. 366e. Plan of the Automatic Sink. to be always on the active rush and make the mechanism of our flush pot absolutely automatic if we wish it to become popular and practical. Figs. 366d to ^66i represent in perspective, section and plan the writer's first device for complete automatic opera- tion. It has been assumed at the outset as an indispensable condition in the design of the apparatus that absolutely 597 Plumbing and Household Sanitation. nothing should be dependent upon the intelligence and care of the servant, and that by no possibility could the waste passages become clogged, either by accident or by design. In short, that the operation should be entirely automatic, and that the form of the outlet should be such that no solid refuse could possibly gain access to it. Fig. 366f. Section of Automatic Sink. It consists of the combination of a square flush pot with an ordinary kitchen sink, in such a manner as to provide a sink of the ordinary appearance and form above, but hav- ing a deep portion or flush pot at the end, with an auto- matic discharge. An upper or horizontal strainer covers the entire flush pot and is hinged to one end of the sink, so that it may be opened when it is desired to use the deep part of the 398 Kitchen Pantry Sinks and Baths. sink. The sink is discharged by means of a self-acting siphon, and a vertical strainer is interposed between the flush pot and its siphon. The short arm of the siphon is trapped with a seal-retaining trap just behind the vertical strainer. This strainer slides upwards in a groove to give access to the trap when desired, but closes again automat- ically by its own weight as soon as released. Clean-out openings are provided at the trap and weir chamber, and gives access to every part of the waste system. No bones and solid refuse can be scraped into the discharge outlet and dropped into the waste pipe, because this pipe ascends instead of descends at the outlet ; and should the trap be clogged, it will simply cause the water to cease to flow out until the obstruction is removed, which can easily be done by simply raising the lower strainer and lifting out the obstruction by hand. The operation of the sink and flush pot is as follows: The sink is used in the ordinary manner until the flush pot fills to the height of the siphon overflow. When this point has been reached, the next discharge of a quart or two of water suddenly emptied from the washing pan charges the siphon and causes the entire contents of the flush pot to rush out through the waste passages, filling them full bore, and scouring them from end to end. The solid matter and large lumps of grease will be left on the bottom of the flush pot, and must be removed by the serv- ant in the proper manner, inasmuch as they cannot pos- sibly be removed in any other way. Thus the great annoyances, expenses and dangers aris- ing from the discharge of sink refuse are avoided. The additional cost of the actual flushing apparatus, over that of an ordinary kitchen sink is trifling. But the sink con- tains its own trap. The trap is also anti-siphonic, and hence requires no back venting. 399 Plumbing and Household Sanitation. The deep portion of the sink may be conveniently used for washing large kitchen utensils which require deeper water than is to be had in ordinary sinks. Figs. 366h and 366i show the writer's recent improve- Fig. 366g. Section of "Securitas Sink. Trap 366h. Section of "Securitas" Sink. ments on this sink, to which he has given the name "Se- curitas" to distinguish it from the old "Sanitas" design. The advantages are greater simplicity and economy and a much better appearance. The trap is a simple return bend, 400 Kitchen Pantry Sinks and Baths. which with the flush pot as a reservoir chamber and the long upcast limb is anti-siphonic. Back pressure is, as we have shown, to be expected in basements, and not siphon- age. The flush pot renders back pressure entirely harm- less, as is evident. The weir chamber is placed preferably under the trap and the whole flush pot attachment thus becomes compact enough to be cast in a single piece. The outlet is enlarged at the strainer to give more room for the water to escape, and the strainer is hinged to the bottom so that it closes automatically and cannot be removed by the cook. This form of trap and strainer is much easier to clean than the old form of bottle trap originally used, and it does away with the need of a clean-out screw under the trap. Fig. 366g shows a form having the weir chamber facing to the left instead of under the trap. This gives room for a trap clean-out should it be preferred. Fig. 366i. Perspective of Securitas Sink. Baths. Fig. 366 from Joly represents in the ancient baths al- most all the operations practised in the public baths after 401 Plumbing and Household Sanitation. the exercises of the gymnasium, namely, rubbing with the flesh brush, massage, nerve adjustment or manipulation and douche bathing. These processes, imitated in the East, are similar to our Turkish baths. Japanese Baths. Prof. Morse compares the bathing facilities of the Jap- anese with ours. Whereas with us ample bathing facilities are confined to a comparatively few rich people, in Japan "nearly every house among the higher and middle classes possesses the most ample arrangements for hot baths; and Fig. 366j. Bath-Tub with outside Heating Chamber. "Japanese Homes." From Morse's even among the poorer classes, in the country as well as in the city, this convenience is not wanting, with the added convenience of public baths everywhere attainable if de- sired." Fig. 366J shows a common form of Japanese bath tub with arrangement for heating the water attached to it. This stove consists of a small wooden water barrel hav- ing a copper smoke flue passing through it in which char- coal is burned. The water passes through a large bamboo tube having a little square door within the tub which the bather may close if the water becomes too hot. "These tubs," says Prof. Morse, "stand on a large wooden floor, 402 Kitchen Pantry Sinks and Baths. the planks of which incline to a central gutter. Here the bather scrubs himself with a separate bucket of water, after having literally parboiled himself in water the temperature of which is so great that it is impossible for a foreigner to endure it." Sometimes the bottom half of the bath tub is made of iron, as in Fig. 366k, and the fire is then built directly be- Fig. 366k Fig. 3661 Fig. 366m. Rath-Tub with Inside Flue. neath it, the bather standing upon a rack of wood to pro- tect his feet from burning. "This tub is called a Goyemon buro, named after Ishikawa Goyemon — a famous robber of Taiko's time, who was treated to a bath in boiling oil." In Fig. 366m a copper tube forming the smoke pipe passes directly through the bottom of the tub. The bottom of the tub forms the fireplace, a simple wire grating sup- porting the charcoal, the combustion of which rapidly heats 403 Plumbing and Household Sanitation. the water. A shallow pan below the grating forms the ash pit. In Fig. 366nthe bath tub is in two sections, separated by a perforated partition of the room, the heating apparatus being on the further side of the partition. The bath tub, like all other plumbing fixtures, should have as little woodwork as possible about it. The first tubs made in modern plumbing work consistea of a wooden box lined with lead, some of which exist to- day. The lead cannot be polished clean and therefore al- ways presents an uninviting appearance. The metal is also so soft that it cannot retain a smooth surface. Next came Fig. 366n. Bath-Tub in Section, the heating oven being outside the Room. From Morse. the zinc tub, which could be kept cleaner and cost less than lead, but is not so durable. It is never now used except in the cheapest kind of work. The copper tub suc- ceeded the zinc, the metal being from 12 to 20 ounces per foot in weight and forming a lining to a wooden frame. This copper tub, heavily coated with tin, has enjoyed pop- ularity in the best houses until the advent of the porcelain tub, when it was found that the appearance of copper, especially when the tin plating became partly worn off, was quite unendurable in appearance, and quite too easily dented to remain fashionable, and it was required to take a secondary place in favor of the Royal Porcelain all earth- 404 Kitchen Pantry Sinks and Baths. enware, or porcelain-lined tub with its snowy whiteness and its icy coldness to the touch until well warmed up by hot water. Cast iron tubs, plain, painted and galvanized, appeared before the porcelain-lined iron, but had only a short career of usefulness, the paint and galvanizing soon wearing off and leaving a very dirty, rusty article, much despised by all but the poor and unfortunate. Cast iron enameled tubs are now so well made that the porcelain lining adheres firmly to the iron and makes a very beautiful and durable finish. It is not so durable, however, as the all crockery tub which, once paid for and properly set, will last as long as the foundations of the house will support its weight. The solid crockery is even colder to the touch than the enameled iron, but it forms a very beautiful though exceedingly heavy and expensive fixture nevertheless. A very good form of tub, recently introduced, is made of copper-lined sheet steel with cast iron supports of orna- mental design and polished wooden rim. This is an open fixture, light and easy to handle, .and has much about it to commend. Similar in construction to the sheet steel tub is one made of a very heavy sheet copper. It has the ad- vantage of being entirely rust-proof and quickly warmed, but does not present the inviting appearance of the por- celain surface. Fig. 368 shows a "needle" bath standing free in the corner of a bathroom having marble or tiled sunken or dished floor. Jets are arranged on all sides as well as above and below. These shower baths are supplied with hot and cold water and mixing devices so that the tem- perature required for comfort as well as health or medical benefit can quickly be attained. Fig. 369 shows in section the construction of a slow- closing faucet devised by the writer to measure and econ- 405 406 Kitchen Pantry Sinks and Baths. omize water. No packing is required around the valve stem. The valve closes with the pressure, instead of in the usual manner, against it. Hence a comparatively flexible spring is used ; and in virtue of this and of the peculiar liM 1 !!! Fig. 368. Needle Bath. construction of the handle it is easily operated, and the spring being never under heavy tension when the faucet is closed, wear is minimized. When the valve closes against the pressure evidently very powerful springs have to be 407 Plumbing and Household Sanitation. ///////^wva \m2ZBZZZZZZZZZBBBZ 7ZZZZZZZZZZZZZZ2. Figs. 369 and 369a. Section and Perspective iew of the Writer's Slow Closing Faucet. used, difficult to operate, and constantly deteriorating under the permanent strain to which they are subjected. More- over, with ordinary faucets the strength of the spring must 408 Kitchen Pantry Sinks and Baths. evidently be greater than the heaviest water pressure ever likely to be used on the faucet valve, so that a considerable waste of power is necessary ; and, since the life of the spring is gradually exhausted with age, and the pressure is liable to be varied in the water mains, either permanently or temporarily, the faucet is soon liable to leak. Moreover, the wearing of the packing required around the valve stem of ordinary faucets is a constant source of leakage and annoyance. In using them it is necessary not only to exert a considerable strain of the fingers in overcoming the pressure of the heavy spring, but to sustain the strain during the whole time the water is running. This proves to be so very inconvenient (especially when, with hot-water faucets, the handle becomes so hot as to burn the fingers) that all kinds of devices are resorted to to tie the handle down, and thus the whole object of the device, for insuring against water waste, is frustrated. When the handle is suddenly released, a severe shock is sustained by the recoil of the spring, which injures and sometimes bursts the water pipes. This faucet is designed to do away with these difficulties. A slight touch of the handle, with instant release, is suf- ficient, with the exercise of very little power, to draw any desired amount of water, from a quart to a couple of gallons, from this faucet. The handle is in the form of a lever and moves forward in an arc in the direction of the nozzle. Drawing the handle down through the com- plete quarter circle opens the valve completely and gives the whole amount of water for which the faucet is orig- inally adjusted when set. Turning the handle through a half or a quarter of this arc gives correspondingly a half or a quarter of this amount of water, and thus a very great saving of water is effected, an advantage which the 409 Plumbing and Household Sanitation. metered-house owner and the water companies greatly ap- preciate. Moreover, the user is enabled to make use of the water while it is running, and thus avoid the annoying waste of time necessary with other self-closing faucets in holding the handle down. A small adjusting screw is provided at the bottom of the chamber under the spring, by means of which the quantity of water to be delivered at each full opening of the handle is regulated when the faucet is set. It is best to regulate the amount by the capacity of the basin it serves, up to the overflow point. This faucet closes slowly automatically, and cannot hammer under the heaviest pressure ever used. Hence there is no possible danger of swelling or bursting of pipes through its use. The spring chamber is closed by a floating valve, which opens when the water is turned off of the house; and all parts of the faucet are then drained off, rendering damage by frost impossible. Instead of packing around the valve stem, the principle of water suction is employed in this faucet to make tight. The closing of the faucet is slow, direct and soft, and does not come to its seat with the turning or grinding movement which ordinarily cuts away washers at the seat. The difficulty, however, with this device, in common with all hydraulic devices depending upon close-fitting plungers for their operation, is a liability to stick in gritty waters. Hence they should only be used where the water supply is pure or well filtered, as is now not uncommon, and as indeed always should be the case everywhere. 410 CHAPTER XXVII. Public Baths. In England, during the Middle Ages, bath- ing the hands in public sight in the banquet hall was the fashion. When the tables at their great feasts were spread, at- tendants entered the hall with basins, ewers and napkins and carried them round to the company, who washed their hands before they sat down to dinner. Sometimes the guests were summoned to wash, however, in the lavatory before meals by the blast of trumpets. The ewers and basins were often made of gold and silver beautifully embossed with jewels and enameled with coats of arms, sometimes costing several hundred dol- lars each. But during the feast the company would throw bones and other refuse from their plates upon the floor, which the dogs looked for as their accustomed share. So that cleanliness at these interesting mediaeval feasts pre- sented a picturesque diversity of form, particularly as Fig\ 371. Mediaeval Bathing at Public Banquet. 411 412 ■S