Digitized by the Internet Archive in 2007 with funding from IVIicrosoft Corporation http://www.archive.org/details/dredgesgolddredgOOnewyrich DREDGES AND GOLD DREDGING NEW YORK ENGINEERING COMPANY New^ SPECIALISTS IN GOLD DREDGING MACHINERY AND ENGINEERING Ilr. 0. Dondoro, i Doar 3ir: IVe ara I 19th in response products, and w^ CO pi 03 of our "be Dredgos and Gla^ DREDGES AND GOLD DREDGING NEW YORK ENGINEERING CO. DESIGNERS AND BUILDERS OF DREDGING MACHINERY 2 RECTOR STREET UNITED STATES EXPRESS BUILDING NEW YORK Cable Address: NYECO, Ne-cv York Telephone JJOJ Rector OUR:, cylDVANTAGES WE are often asked why we located in the East. Briefly, because we are right in the center of produc- tion of all the material entering into the construction of a dredge. The largest part of the machinery is of special steel, cast, wrought, manganese, chrome and nickel, all of which are pro- duced only in the East and at our door ; in fact, most of the ma- terial for all of the important parts of every dredge built in this country is ^""^^^li^MP^ ^-*.a«,«— . ,|^_ produced on the Atlantic Coast. Being located in the very center of production, we procure the best material quickly and cheaply. INSPECTION AND SELECTION OF RAW MATERIAL Our supervising engineers are constantly visiting the mills, inspecting, selecting and testing our materials; there- fore, we get the best selection and quality to meet our wants in the shortest time possible. Hence we are able to turn out complete dredges in much shorter time, and at less cost, than any of the Western Manufacttirers. We are the first and only concern in this country to devote its whole attention exclusively to the designing and building of gold dredges; therefore, we are especially well equipped to do this work much better and more quickly than other concerns; for with them, dredge building is only a side line, and their principal business, which receives their best efforts, is the manufacturing of some other lines of product. Some of our engineers were taken from the Cali- fornia dredging fields, and thus we have the advantage of the many lessons learned in that country. NEW YORK ENGINEERING CO We have done much to de- velop dredge architecture and to promote gold dredging in gen- eral ; therefore, to those interested in this subject, we suggest the reading of our booklet on ''Drills and Prospecting," illustrating the Empire Hand Prospecting Drill and its application in determining the values and characteristics of dredging or placer ground. It also contains much valuable infor- mation and many tables of use in placer and dredge mining, and it will be sent on application. We are the first concern to make a specialty of export work, and we are particularly well equipped to handle this line, being familiar with the conditions ex- isting in most of the gold-bear- ing placers of the world. We have recently equipped many of these properties with successful dredges. TYPES In the experimental period of dredge construction in this coun- try, many failures resulted in attempting to use the hydraulic, or suction, and the dipper and clam-shell types of dredges. These failures were due to several circumstances: First, the suction dredge did not lift any appreciable amount of gold. Second, it did not clean uneven and hard bedrock. Third, in the dipper and clam-shell types the joints in the buckets could not be made water-tight and most of the gold was lost with the great rush of water through these joints. Fourth, these types deposited the material in large quantities, at intermittent periods, whereas a continuous feed is most essential to the close saving of gold. EMPIRE HAND PROSPECTING DRILL DREDGES AND GOLD DREDGING We build but the one type of dredge for gold mining, namely, the elevator bucket type now universally recognized as unquestionably the best machine for handling a maximum quantity of material at a minimum cost. ELEMENTS An Elevator Bucket Dredge comprises: First, a Digging Apparatus at the bow of the boat, rais- ing and delivering the material into a screen. Second, a Revolving or Shaking Screen located about amidships for the sizing and washing of the material. Third, an Elevator, or Stacker, at the stern, which con- veys the over-size material from the screen to a necessary distance behind the dredge and on to the tailing pile. Fourth, a Gold Saving Device for recovering the precious metal from the material passing through the perforations of the screen. Fifth, a Pump- ing Apparatus furnishing an ample water sup- ply for washing and sluicing the gravel. Sixth, a Winch controlling the two bow lines, two stern lines and a head line, as well as the spud lines. By these means the dredge may be placed and held in any position necessary for its operation. Each element is complete in itself and is combined in regular coordination, mounted on a scow, and forming a complete, simple and practical excavating, screening, wash- ing and stacking apparatus, the operation of which is prac- tically automatic and continuous. All the above is operated by two men per shift at a cost as low as two and one-quarter cents, and seldom exceeding eight cents per cubic yard. 5 NEW YORK ENGINEERING CO. BUCKET AND ROLLE passing- through the screen and sluice-box which saves the gold and conveys the tail- ing a distance from the stern of the dredge: this does away with the stacker or elevator. BUCKET LINE The excavating appara- tus consists of an endless chain of buckets of great weight and strength that will We generally advise the stacker type of dredge, which is in part a combina- tion of gold-saving tables with a tailing stacker at the rear of the dredge for ele- vating the over-size mate- rial from the screen. Under some conditions, we recom- mend the sluice-box type of dredge of the single lift style, wherein tlie buckets dump the material into a short screen wnth large per- forations, the under-size falling directly into a long CLOSE-CONNECTED BUCKETS cut and dig, not only the gravel, but the bedrock. The ac- tion of the buckets is slow and power- ful, so that the g o 1 d-b earing gravel is picked up in mass with very little agita- tion. As the buck- ets are water- tight, there is no opportunity for the gold to be lost DREDGES AND GOLD DREDGING and the material is delivered into the washing and separat- ing screen in an almost continual stream under the best con- ditions for the saving of the metallic content. Generally the close-connected type of bucket line is used, that is, each bucket connected directly to the next one; but under some conditions, the open type is advisable. Then the buckets are spaced by a connecting link, thus giving alternate bucket and link. This link is so constructed that in digging it also carries about a third of a bucketful of material. It is so made that the hood and lip, completing the bucket, may be put on to the link after the dredge has been operated some time, if the ground should prove this to be advisable, thus making a close- connected bucket line, as illustrated on page 4. BUCKET LADDER LADDER The ladder is of the built-up girder type made of angles and plates most substantially braced and reinforced through- out its length (built in sections for transportation) and hung by its upper end to the main gantry on massive steel cast- ings. LOWER TUMBLER At the lower end of this ladder a lower tumbler is car- LOWER TUMBLER NEW YORK ENGINEERING CO. ried in heavy cast steel, water and grit-proof bearings. This tumbler is made of a special tough, hard, cast steel and fitted with manganese steel wearing plates that are readily renewed when worn out. UPPER TUMBLER AND SHAFT UPPER TUMBLER The upper tumbler, which drives the bucket line, is faced with renewable manganese steel plates and is carried on a shaft just beyond the upper end of the ladder; this shaft is driven by a double set of cast steel gears mounted on each end of the shaft with the upper tumbler between them. This driving of the upper tumbler shaft from both ends prevents its twisting and breaking in the STEEL DRIVING GEARS UliddlC, aS SO OftCU DREDGES AND GOLD DREDGING MAIX DRIVE BEARINGS WITH 3-INCH STANDARD BEARING ON TOP TO SHOW COMPARATIVE SIZES happened with the old style of single drive from one end of shaft only. All of this driving gear is mounted on structural steel v^ork so as to be self-contained and always in perfect align- ment. Carrying rollers are mounted on the ladder every few feet, for the buckets to travel over ; these rollers revolve in dirt-protected bear- ings of the ball and socket order, so that they adjust themselves to any uneven move- ment of the ladder and never get stuck. Each roller, with its shaft is cast all in one piece, thus doing aw^ay with the eld trouble of their becoming loose on the shaft. The ladder, with its line of buckets, is raised from the outer end by a separate winch driven by the main bucket line engine or motor. This arrangement obtains the benefit of the largest power unit in the dredge to raise the ladder as quickly as possible, as time occu- pied in raising the lad- der is lost in digging. The digging end of the dredge is the most important part, as the data from operating dredges show that at least twenty-five per cent of all the stop- pages and troubles on board are due to the bucket line. Therefore, we have made every effort to de- velop this end to its highest efficiency, and our buckets, pins, lips, etc., are larger, stronger and heavier than those of any other manufacturers. The material as it is dug and elevated is dumped into a hopper, from which it is fed into the screen. LADDER WITH CARRYING ROLLERS NEW YORK ENGINEERING CO. SCREEN This screen is either of the revolving or shaking type, depending on the character of the material to be handled, and it is set on a grade so that the material gradually travels through its length, while a perforated water pipe furnishes ample water to all parts of the screen for thorough- ly washing the gravel and releasing all the gold contained therein. Our revolv- ing screens are carried on rollers which are mounted REVOLVING SCREEN DRIVE in special water are cast as an integral part of the roller so as to avoid many troubles that arise from these rollers coming loose on their shafts. Ample adjustment is provided in these bearings for all wear. and grit-proof bearings. The shafts SCREEN ROLLER AND BEARINGS TABLES AND SLUICES The smaller gravel and sand pass through the perfora- tions of the screen, together with the gold, and are distrib- uted evenly, by a special device, over the tables, which are designed to suit the various characteristics of the gold. This distributing device is most important, and it automatically 10 DREDGES AND GOLD DREDGING provides each table with its requisite proportion of gravel so that there is no overloading of any one table. The gold is caught either by interference, or by gravity, often by the aid of quicksilver. Gold, microscopically fine, is thus success- fully recovered by our design of distributing device and tables. Most of the gold is recovered on the first few inches of the tables, but sluice-boxes are provided with angle iron rifBes (which gives a good wearing bottom) to convey the tailing to the stern of the dredge. Very little gold ever travels so far, thus proving the efficiency of the tables as a gold saving device. STACKER The over-size material that is discharged from the end of the screen is deposited on the conveyor belt, which runs on specially constructed rollers, mounted in water-proof bearings, and carried on a struc- tural steel ladder simi- lar to the digging lad- der, but lighter in con- struction. The now barren gravel is dis- charged on the tailing pile at such a height as to prevent interference with the movements of the dredge. PUMPS Our centrifugal pump, for furnishing the water for aW washing purposes, is specially designed for this particular work, being of large diameter and running at a moderate speed, thus giving durability and economy. It is direct- connected to a marine engine, in our steam dredge, and to an electric motor, in the electrically-driven dredge. This pump furnishes ample water to the screen for all washing purposes. A smaller pump is used for cleaning up, wash- ing down the decks, pumping out the bilge, and priming the larger pumps. TAILINGS PILES II NEW YORK ENGINEERING CO. CENTRIFUGAL PUMP In some in- stances a centrif- ug-al sand pump is required for elevating- and conveying fine tailing a distance to the rear of the dredge. WINCH One of the most important features of oper- ation is the meth- od of handling the dredge, and it is owing to this excellence in our design of winch that a machine handling 5000 cubic yards per day requires only two men on a shift to operate same. This facility in moving the dredge is accomplished by the use of a winch or winding engine, having six or more drums, under the direct control of the operator, or winchman. The four side lines run from this winch to each corner of the dredge and are then led to the shore and anchored. A fifth, the head line, leads from another drum to the bow and forward, and is anchored a few hundred feet ahead of the dredge, thus holding it in position against the dig- ging bank. By the four side lines and the one head line the WINCH 12 DREDGES AND GOLD DREDGING CONTROLLING LEVERS IN PILOT HOUSE Operator can place and hold the dredge in any position he desires by a simple movement of levers. The throttle valves and controlling apparatus for all of the machinery of the dredge are placed in a pilot house, so situated as to command a full view of the operations. The winchman has direct control of all of the apparatus on the dredge through a num- ber of levers arranged similarly to those in a railroad switching tower and placed in the pilot house. On our electrically- driven dredge, the switchboard and all various motor controls are located in the pilot house under the hand of the winchman, and the only other help re- quired on board is an oiler, or motorman. Our winch has many distinctive features; each drum is mounted in its own independent bearings at each end and is not carried by the shaft, as ordinarily arranged. There- fore, there is no diffi- culty in lu- brica t ing the bear- ings of the drums and the shafts are not strained by the pull of the lines on the drums or by the power or p r e s sure exerted by applying the brakes to the drums. The sole func- 13 INTERIOR OF HULL SHOWING FRAMING NEW YORK ENGINEERING CO tion of the shaft is to carry the clutches that revolve the drums. These points will be readily appreciated by all ex- perienced winchmen. The winch is far stronger and simpler than any other similar machine of today. It is assembled in a massive frame of structural steel so that the alignment is perfect and per- manent and the whole is self-contained. HULL All of the machinery is mounted on a scow having a center well extending aft to about amidships; this scow is designed according to the requirements and must be ex- ceedingly stiff. It is stanchly built of the best selected tim- ber, with heavy frames closely spaced and tied together by longitudinal stringers and by two solid bulk- heads running fore and aft through the middle of scow on each side of the well. STEEL SUPER- STRUCTURE We have just com- pleted a dredge wherein the forward, main and stern gantries, together with the entire truss work, are of structural steel latticed girders ; the whole, when com- pleted, forms a Howe Trussed Girder extend- ing the entire length of the dredge, as illustrated on page 2. In this construction, it will be noticed that all of the strains in digging are confined within this complete steel structure and are not transmitted through the hull, as in the ordinary form of wooden construction, wherein the wooden truss is built up as part of the hull. This structural steel truss, or girder, is complete within itself and simply rests on the bottom of the hull, which only serves to float it. DETAIL OF STEEL GANTRY 14 DREDGES AND GOLD DREDGING This relieves the hull from many of the strains that tend to wreck it. This is quite a radical departure from anything here- tofore attempted, and while it makes quite an expensive form of construction, still we believe that the results justify this expense. We are also prepared to design and build com- plete steel hulls when advisable. These are so built that they can be knocked down for ship- ment or transportation, and readily assembled on the ground. MAIN DRIVE ENGINE ENGINES In the steam-driven dredge the main bucket-drive en- gine is of the double-cylinder marine type, reversible, ex- ceedingly heavy, with extra large shaft and cranks, and in our large size, is compound condensing. The water used in washing the gravel is pumped through the condenser on 15 NEW YORK ENGINEERING CO. WATER TUBE BOILER its way to the screen; and, therefore, serves for both condensing and washing pur- poses. Auxihary en- gines of special de- sign and of substan- tial character serve to drive the other appa- ratus on board, such as the screen, winch and conveyor. BOILER Our boiler, in most instances, is of a spe- cial water-tube type; and where wood is to be used, it is designed with an extra large and deep furnace, which is so important in burning the poorer grades of wood. All of the tubes in this boiler are straight and acces- sible, and therefore readily cleaned. This boiler is self-contained and set within heavy sheet iron work, lined with asbestos, excepting the furnace, which is lined with firebrick so ar- electric motor ranged as to be readily renewed. As the exhaust steam is condensed and returned to the boiler, there is no danger of the boiler becoming fouled with mud or scale. ELECTRICAL EQUIPMENT Our steam dredge is usually ar- ranged so that it can be changed in- to an electrically-driven dredge by substituting electric motors for the engines and taking off the boiler. Alternate current is always used on account of its many advantages in i6 generating set DREDGES AND GOLD DREDGING long-distance transmission; the motors, being of the induc- tion type, are also better suited for dredging purposes than direct current motors. The motors are all fused to cut out at a certain over- load, and circuit-breakers are also installed to act auto- matically at a desired overload. The current is brought on board the dredge through water-proof flexible cable at high tension, and then transformed or stepped down for the dif- ferent motors, as well as for the lighting circuits. In our steam-driven dredge a complete self-contained, steam-driven generator or dynamo set is furnished for lighting the dredge. On our electric dredge we have a separate motor for each drive. The bucket-line driving motor is connected by a belt and gearing so as to give flexibility, and when the buckets strike against an obstruction in digging, an auto- matic release, or circuit-breaker, stops the chain of buckets instantly. Most of the motors on board are direct-connected. OUR IDEALS There has been a marked tendency on the part of sev- eral builders of gold dredges to standardize design; and in order to save expense, to supply a stock dredge of one design for all kinds of work. This is like attempting to cure all ills with a universal remedy — a manifest impossibility. We believe that each dredge should be designed and constructed to suit the conditions under which it is to oper- ate, therefore we study each proposition thoroughly and de- sign and build accordingly, instead of trying to make one equipment fit all conditions. In designing our dredge, we have made simplicity one of the fundamental features, and we have made a specialty of developing the wearing parts, making them renewable at every point practicable with as little expense and loss of time as possible. We use special hard steels in every place advisable in order to give extra long life and durability to these parts. A greater factor of safety is used in dredging than in any other line of work, for the repairs and consequent shut- downs must be kept at a minimum. These are the most serious items of expense in operating. 17 NEW YORK ENGINEERING CO. EXPORT WORK Our geographical position favors us for all export work. Our definite knowledge of all the various placer grounds of the world, and especially the particular conditions under which they exist, enables us to command this export work. Since we. have become active in this field, we have secured all the contracts for every dredge that has been exported from this country. We have given special attention to conditions in Colom- bia, British, Dutch and French Guiana, Brazil, Venezuela, Terra del Fuego and Siberia, and we have the knowledge that best fits us to build dredges for these and other foreign countries. We design our dredges and make shipment ac- cording to these conditions, giving due regard to weight and size of largest pieces. As we are making a specialty of export work, we find that our dredges are often compared with those of foreign makers, and in so doing, one discovers a great difiference in prices and a greater difiference in weights. We therefore ask that in making this comparison, that it be noted that the American gold dredges are usually more than double the weight of the foreign dredges, and the use of special high grades of steel is extensively carried out by us. While our cost is much greater, the net results more than justify this extra cost. The ideal dredge handles a large yardage at a low cost and our dredge has been developed to this ideal. The result is that the American dredges are digging far more ground and make a cleaner saving at less cost per cubic yard than are any other dredges of today. Therefore, if one is con- sidering final, definite results, they will do well to study the history and success of American dredges and make a close comparison with other dredges before deciding. A brief comparison between one of the leading European makes and our dredge is herewith given below : Foreign Dredge American Dredge Scow 90' long, 25' wide, 7' deep 100' long, 36' wide, 7' deep Capacity of Buckets . Speed of Buckets . . Length of Ladder . . Revolving Screen . . Main Drive Engine 4^ cu. ft. each 3^ ft. each 12 per minute 25 to 30 per minute 60' 60' 3' 9" dia., 14' long 4' 6" dia., 22' long 25 horse-power 50 horse-power Total Weight of Machinery 80 tons 165 tons 18 DREDGES AND GOLD DREDGING It will readily be seen from this, that, while the buckets of the foreign dredge are twenty-five per cent larger, yet they have only one-half the power to drive them and they run less than one-half as fast. They also weigh only half as much. The great disparity in total weight of machinery speaks for itself and readily explains why the American ■wp-;"^'^' ''''''''''-mi ^if^ HULL IN COURSE OF ERECTION liS^UkOr. dredges stand up to the hardest kind of work, and give far more profitable and satisfactory results in their operation. We prefer to build and erect dredges complete and turn them over running, or we will furnish the machinery only f. o. b., in which case we send a full set of working plans and instructions. We will send competent men to superintend the entire construction of hull and erection of machinery and put the dredge in full and complete operation, breaking in and training the local laborers to operate same. Where two or more dredges are to be installed, it is generally advisable to have them electrically-driven with the power-generating station located where convenient to fuel, etc., and to have the current transmitted to the dredge. This arrangement saves room on board the dredge, by doing away with the boiler, STACK OF BUCKETS 19 NEW YORK ENGINEERING CO. etc., and it is also a saving in doing away with the hauHng and handHng of fuel. POWER PLANTS Where head and quantity of water can be secured, elec- trical power can be generated and transmitted any reasonable distance to the dredge. Where a central power-generating station is required, we are prepared to design and build the same complete in every detail, either with water or steam power ; we have had large experience in this line of work. As no two dredge propositions are alike, we prefer to have one of our representatives visit the ground, and we have competent engineers for this particular work. Thus we can, in each particular instance, recommend and advise to the best advantage, concerning the size and other details of the dredge that al- ways require modifications to fit the particular conditions peculiar to each dredging area. We have had considerable experience in working ground containing a large percentage of clay ; we have been able to handle it success- fully with our special devices. nt I w^ POWER HOUSE CENTRAL PLANT SIZES AND CAPACITIES Dredges are commonly known by the size of the buckets, that is, the cubical contents of each bucket, and the following sizes have been largely adhered to : 3>4 cubic foot buckets, which have a theoretical capacity of about 3000 cubic yards in 24 hours. 5 cubic foot buckets, which have a theoretical capacity of about 5000 cubic yards in 24 hours. 7 cubic foot buckets, which have a theoretical capacity of about 6500 cubic yards in 24 hours. 10 cubic foot buckets, which have a theoretical capacity of about 9000 cubic yards in 24 hours. 20 DREDGES AND GOLD DREDGING 13 cubic foot buckets, which have a theoretical capacity of about 12,000 cubic yards in 24 hours. Their actual digging capacity will vary considerably and is dependent, not only upon the character of the ground, but also upon the ability of the dredge-man and many local con- ditions. A fair average, however, in actual digging is about from 60 to 70 per cent of the theoretical capacity. Prospecting. — Prospecting dredging ground is usually simple and cheap, and money devoted to this object makes far more certain the knowledge of returns, and it results in the installation of suitable dredges. The Empire Hand Prospecting Drill is well adapted for this work. We advise careful prospecting of the ground before the installation of the dredge; for it is far more satis- factory for you to have the dredge designed and built so that it is best adapted to the conditions under which it is to oper- ate. We also take pride in having our dredges work well and thus be worthy of our name. We build nothing but gold- dredging machinery, and therefore we must build the best gold dredges, otherwise we would fail, for we have no other line of product to rely on. With all other manufacturers, dredge building is merely a side issue. DREDGING The popular conception of mining enterprises is one of extremely large returns on an investment, or nothing at all; in other w^ords, a gamble where luck and chance govern all. On the other hand, industrial or commercial enterprises are generally supposed to give a moderate but sure profit on the investment. It has remained for the dredging of gold, from alluvial areas, to upset previous notions in these regards and to demonstrate beyond a question that such mining is as much a business enterprise as is any manufacturing indus- try. It has the great advantage of having an absolutely un- limited and unfluctuating demand for its product which is not possessed by any other business than that of producing gold, the standard of all values. For this reason gold-dredging is attracting widespread attention among investors and offers great inducements to them; and when the ground is properly prospected and NEW YORK ENGINEERING CO. equipped with a skillfully designed and well-built dredge the returns can be predicted with an exactness that challenges belief. . Thus, corporations operating gold dredges have cal- culated returns for years in advance, and results have shown an accuracy in forecasting the returns that is not to be equalled in manufacturing, or in the marketing of any other products. Market conditions, supply and demand, as well as other changeable factors, set all calculations at variance, while gold — the product of gold-dredging — has a market and a value absolutely unwavering and a demand unlimited. In times of panic or business depression, the gold dredges roll on, and their products, in greater demand than ever, are sent to the mint in exchange for gold coin. CONDITIONS It is not easy to state in exact terms just what condi- tions are essential for success in gold-dredging, but there are a number of factors which have such an individual import- ance that the lack of any one of them may result in failure where otherwise success should have been attained. There is no one governing condition more important than machinery of design and construction suitable for work- ing in the area chosen for exploitation by the dredging method. Thus, there are several instances where faulty de- sign or construction have wrecked undertakings where a plentitude of gold should have furnished rich reward. There- fore, we emphasize not only the advantage of care in the selection of the dredging plant, but also the importance of thorough and careful investigation of the dredging ground under consideration, so that the dredge may be designed and built to meet the existing conditions. To assist in this mat- ter, we are manufacturing the Empire Hand Prospecting Drill, which is the best tool for testing dredging ground. We are dredge operators ourselves, and we are in a position to advise prospective buyers in all regards, and a wide and varied experience makes our advices on dredging matters valuable. We are also in a position to assist those having dredging ground of proven value, in financing the same. Unlike some manufacturers, we have no fads or fancies, and our sole ob- ject is to build and supply suitable dredges of great weight 22 DREDGES AND GOLD DREDGING and strength and of the best material and designed for the most economical operation. DREDGING POSSIBILITIES The application of the dredging process is wide, and it is becoming more comprehensive. In early operations it was confined to river beds, but now flats adjacent to rivers, benches or terraces nearby, deposits in arid regions, sea beaches and bottoms, lake bottoms and frozen gravel in frigid zones, are also handled with success. The one paradox seems to be the dredging of arid areas, but water sufficient for floating dredges is now had by pumping from deep wells, drilled for that purpose with the Empire Hand Drill. The quantity of water required by dredge is small, generally 500 gallons per minute is ample. Thus, dredging is a wide industry and includes such enterprises as excavating lake bottoms for Aztec ornaments of gold (cast into the waters to acquire favor from the gods and protection from the invading Spaniards), the recovery of diamonds, tin and other metals and minerals existing in deposits either subaqueous or subarial. The ultimate depth to which dredges can dig has not been determined, and alluvion about 100 feet deep is now being handled with great success. The probability is that this depth will be materially increased. Greater depths have not been attempted at present, because no areas pos- sessing dredgeable characteristics and of greater depth than 100 feet have- been investigated. Banks as high as 30 feet above the water level are successfully handled. In order that one may understand what difficult ground has been successfully dredged, and in many cases seemingly unsurmountable obstacles having been encountered, we cite a few examples, as follows: Dredging in arid regions (as noted before) ; dredging cemented gravel so indurated that it must be blasted; dredging frozen gravel some of which must first be thawed; dredging gravel lying on a tough, blocky, schist bedrock, and to a depth of six feet into the bedrock ; dredging gravel which contains occasional boulders weighing two tons, and having overburden over thirty feet deep or sometimes containing tenacious clay and buried tim- bers. These are a few instances of what may be accom- 23 NEW YORK ENGINEERING CO. plished where intelligent investigation, appropriately de- signed and well constructed machinery have combined to bring about great success. DREDGING DRY PLACERS It is often supposed that dredging can only be carried on in rivers, or that the placer must be fully under water. This is erroneous, as interior or paddock dredging is car- ried on where there is no body of water; in fact, it may be done on elevated benches or plateaus, or in flat and arid areas devoid of any running water. To accomplish this it is only necessary to form a small pond about two hundred feet square and four or five feet deep. This may be done by ex- cavating or damming, thus forming a pond to float the dredge in ; and a small supply of water, which can be pumped or flumed from a distance, will take care of the seepage and evaporation. In this small pond the dredge can be made to travel over any part of the property and carry the pond along with it, inasmuch as the dredge fills in behind zvith the mate- rial that is removed from the front. The introduction of gold-dredging has widened the min- ing horizon to a considerable degree, and there are great volumes of gold in subaqueous deposits formerly unattain- able, but now placed within the reach of recovery by this process. There are also large amounts of gold in deposits sub- aqueous not heretofore workable but that are now success- fully exploited because of the cheapness of dredging. There is only one method of placer mining cheaper in operation — hydraulic mining — and then only under conditions that must be considered unique. As a general statement, dredging is the cheapest known method of mining, and it is not at all un- likely that the lowest cost of hydraulic mining ( i ^ cents per cubic yard) will soon be surpassed in dredging (the lowest cost for dredging, at present, is 2}^ cents per cubic yard, with further reductions in prospect). Countries like those of South America possess immense possibilities in the dredging field, having produced from placers over Two Billion Dollars ($2,000,000,000.00) worth of gold, or about one-fourth of the total gold product of the world. 24 DREDGES AND GOLD DREDGING Any rivers draining- auriferous districts are worthy of investigation. Thus, all the continents and many of their sub- divisions have possibilities awaiting investigation and de- velopment of dredging areas which will add materially to the gold production of the world. HISTORICAL The elevator or bucket type of dredge had its origin in the remote but advanced country of New Zealand, and much of its development was brought about in that country, but it remained for American enterprise to improve the New Zealand type and bring it to its present state of perfection. In the beginning, the natives of New Zealand used a bag, made of sheepskin, laced around or on to an iron frame which was attached to the end of a pole or sweep; this was mounted on a raft of crude construction and arranged so that the bag could be dragged along the bottom of the river, and when filled, raised and its contents rocked, or sluiced, and the gold thus recovered; man power was used exclu- sively. This crude form finally evolved into the prototype of today, having a line of very light sheet-iron buckets oper- ating at the end of a small boat. But it remained for Amer- ican ingenuity to bring the gold dredge to its present-day maximum development in which we find a machine of tre- mendous weight, strength and capacity, digging approxi- mately 200,000 cubic yards per month in alluvion 100 feet deep, at a less cost than ever before. Many of our features and designs are covered by patents, and we trust they will be respected by all other manufac- turers. We have had a broad experience in the handling of large quantities of material and are particularly well equipped to work out any special designs in the handling of gravel con- taining black sand and other valuable minerals or precious stones. On receipt of general information we will be glad to make suggestions and quote prices and terms. Your correspondence is earnestly solicited. NEW YORK ENGINEERING COMPANY. 25 NEW YORK ENGINEERING CO MINERS' INCH MEASURING BOX EXPLANATION OF MINERS INCH MEASUREMENT The term "miners' inch" is of CaHfornia origin, and not known or used in any other locahty, it being a method of measurement adopted by the various ditch companies in dis- posing of water to their customers. The term is more or less indefinite, for the reason that the water companies do not all use the same head above the center of the aperture, and the inch varies from 1.36 to 1.73 cubic feet per minute; but the most common measurement is through an aperture two inches high and whatever length is required, through a plank iJ4 inches thick, as shown in cut. The lower edge of the aperture should be two inches above the bottom of the meas- uring box, and the plank five inches high above the aperture, thus making a six-inch head above the center of the stream. Each square inch of this opening represents a miners' inch, which is equal to a flow oi 1^/2 cubic feet per minute. 26 TABLE OF FLOW OF WATER IN OPEN CHAN- NELS, IN MINERS' INCHES BASE TO PERPENDICULAR OF THE SIDE SLOPES BEING AS 3:4 T. 3.3 Feet. T. 4.4 Feet. T. 5.5 Feet. T. 6.6 Feet. T. 7.7 Feet. T. 8.8 Feet. B. 1.5 Feet. B. 2.0 Feet. B. 2.5 Feet. B. .1.0 Feet. B. 3.5 Feet. B. 4.0 Feet. Fall per D. 1.2 Feet. D. 1.6 Feet. D. 2.0 Feet. D. 2.4 Feet. D. 2.8 Feet. D. 3.2 Feet. Mile Section Section Section Section Section Section in Feet. 2.88 5-12 8.0 11.52 15.68 20.48 Sq. Feet. Sq. Feet. Sq. Feet. Sq. Feet. Sq. Feet. Sq. Feet. 4 88.3 182.3 371.3 617.3 897.6 1350.0 5 99.0 204.0 415.5 674.6 1070.0 1510.0 6 108.3 223.3 455.0 739.0 1096.0 1654.0 7 114.0 241.3 491.3 798.0 1187.0 1786.0 8 125.0 257.6 525.0 853.3 1270.0 1909.0 9 132.6 273.6 557.0 905.0 1346.0 2025.0 10 139.6 289.0 590.0 954.0 1419.0 2135.0 11 146.6 302.3 615.3 1000.6 1488.0 2240.0 12 153.3 316.0 643.3 1045.0 1555.0 2355.0 13 159.3 328.6 669.3 1087.6 1618.0 2434.0 14 165.5 341.3 694.6 1129.0 1680.0 2526.0 IS 171.3 353.3 719.6 1168.0 1738.0 2615.0 16 176.6 364.6 742.3 1206.0 1800.0 2700.0 17 182.3 376.0 765.3 1243.0 1850.0 2784.0 18 187.6 336.6 787.6 1280.0 1904.0 2866.0 19 192.6 397.3 809.3 1315.0 1952.0 2943.0 20 197.6 407.6 830.0 1349.0 2007.0 3020.0 21 202.6 418.0 851.0 1382.0 2056.0 3094.0 22 207.3 427.6 870.6 1415.0 2105.0 3166.0 23 212.0 437.3 890.3 1450.0 2152.C 3238.0 24 216.6 446.6 909.6 H78.0 2198.0 3307.0 25 221.0 457.3 932.6 1508.0 2244.0 3370.0 T. 9.9 Feet. T. 1 1 Feet. T. 13.2 Feet. T. 16.4 Feet. T. 17.6 Feet. T. 19.8 Feet. Fall per B. 4.5 Feet. B. 5 Feet. B. 6.0 Feet. B. 7.0 Feet. B. 8.0 Feet. B. 9.0 Feet. Mile D. 3.6 Feet. D. 4 Feet. D. 4.8 Feet. D. .5.6 Feet. D. 6.4 Feet. D. 7-2 Feet. in Feet. Section Section Section Section Section Section 25.92 32 46.09 62.72 81.92 Sq. Feet. 103.68 Sq. Feet. Sq. Feet. Sq. Feet. Sq. Feet. Sq. Feet. 4 1870.0 2503.0 3903.0 6430.0 9223.0 12613.0 5 2090.0 2763.0 4363.0 7190.0 10310.0 14103.0 6 2290.0 3026.0 4780.0 7876.0 11293.0 15450.0 7 2473.0 3270.0 5160.0 8510.0 12200.0 16683.0 8 2651.0 3493.0 5516.0 9096.0 13040.0 17836.0 9 2808.0 3703.0 5853.0 9650.0 13830.0 18920.0 10 2956.0 3903.0 6170.0 10166.0 14580.0 19940.0 11 3106.0 4096.0 6470.0 10663.0 15290.0 20440.0 12 3238.0 4280.0 6760.0 11133.0 15970.0 21846.0 13 3371.0 4453.0 7036.0 11593.0 16623.0 22736.0 14 3498.0 4623.0 7300.0 12030.0 17250.0 23593.0 15 3621.0 4783.0 7555.0 12453.0 17856.0 24426.0 16 3740.0 4933.0 7803.0 12863.0 18443.0 25223.0 17 3855.0 5080.0 8043.0 13260.0 19010.0 26003.0 18 3966.0 5240.0 8276.0 13643.0 19563.0 26756.0 19 4074.0 5383.0 8503.0 14016.0 20050.0 27493.0 20 4181.0 5523.0 8723.0 14380.0 20616.0 28203.0 21 4285.0 5660.0 8940.0 14733.0 21130.0 28900.0 22 4385.0 5793.0 9150.0 15083.0 21626.0 29580.0 23 4484.0 5923.0 9356.0 15430.0 22113.0 30246.0 24 4580.0 6050.0 9556.0 15753.0 22590.0 30896.0 25 4675.0 6176.0 9866.0 16076.0 23053.0 31533.0 T.— Top. B.— Bottom. Note. — To obtain the number of cubic feet instead of miners' by one and one-half. This is on the assumption that one miners' half cubic feet. 27 D.— Depth, inches, multiply the above inch equals one and one- TABLES FOR CALCULATING THE HORSE POWER OF WATER MINERS' INCH TABLE. 1 CUBIC FEET TABLE. The following table gives the Horse Power The following table gives the Horse Power of one miners inch of water under heads of one cubic foot of water per minute under from one up to eleven hundred feet. This heads from one up to eleven hundred feet. inch eauals i ^ cubic feet per minute. Heads Horse Heads Horse Heads Horse Heads Horse in Feet Power. in Feet. Power. in Feet Power. in Feet. Power. 1 .0024I47 290 .700263 I .0016098 290 .466842 20 .0482294 300 .724410 20 .032196 300 .482940 30 .072441 320 .772704 30 .048294 320 •515136 40 .096588 340 .820998 40 .064392 340 .547332 50 .120735 350 .845145 50 .080490 350 .563430 60 .144882 370 .893439 60 .096588 370 .595626 70 .169029 390 .941733 70 .112686 390 .627822 80 .193176 400 .965880 80 .128784 400 .643920 90 .217323 420 1.014174 90 .144892 420 .676116 100 .241470 440 1.062468 100 .160980 440 .708312 110 .265617 450 I. 086615 no .177078 450 .724410 120 .289764 460 1.110762 120 .193176 460 .740508 130 .313911 470 1.134909 130 .209274 470 .756606 140 .3.38058 480 I.I 59056 140 .225372 480 .772704 150 .362205 500 1.207350 150 .241470 490 .788802 160 .386352 520 1.255644 r6o .257568 500 .804900 170 .410499 540 1.303938 170 .273666 520 .837096 180 .434646 560 1.352232 180 .289764 540 .869292 190 .458793 580 1.400526 190 .305862 560 .901488 200 .482940 600 1.448820 200 .321960 580 .933684 210 .507087 650 1.569555 210 .338058 600 .965880 220 •531234 700 1.690290 220 .3541 50 650 1.046370 230 .555381 750 1.811025 230 .370254 700 1. 1 26860 2-40 .579528 «oo 1. 03 1 760 240 .386352 750 1.207350 250 .603675 900 2.173230 250 .402450 800 1.287840 260 .627822 1000 2.414700 260 .418548 900 1.448820 270 .651969 1100 2.656170 270 .434646 rooo 1.609800 280 .676116 280 .450744 HOC 1.770780 WHEN THE EXACT HEAD IS FOUND IN ABOVE TABLE. Example. — Have 100 foot head and 50 inches of water. How many Horse Power? Bj-^ reference to above table the Horse Power of i inch under 100 foot head is .241470. This amount multiplied by the number of inches, 50, will give 12.07 Horse Power. WHEN EXACT HEAD IS NOT FOUND IN TABLE. Take the Horse Power of i inch under i ft. head and multiply by the number of inches, and then by number of feet head. The product will be the required Horse Power. The above formula will answer for the cubic feet table, by substituting the equivalents therein for those of miners' inches. Note. — The above tables are based upon an efficiency of 85%. WATER REQUIRED AND EFFECTIVE WORK OF HYDRAULIC GIANTS in 1 0^ 1^ Volumes of Approximate . )r^t oSs Water Necessary Amount of Gravel ^--^ ^1^ "■fiP-l r- for Effective (average ground) "o u -•.£5 It; c ?^°c Work in Washed in 24 ^;2^^ ^T^.S Miners' inches. Hours in Cubic s OpH it! Yards. s^ Q U i-in. Noz. IH-in.Noz. i-in. Noz. iH-in. Noz 100 20 45 40 90 5 2V2 I and ij^ 150 25 55 50 110 200 30 2-in. Noz. 3-in. Noz. 60 2-in. Noz. 130 3-in. Noz. 100 80 i8s 160 370 I 7 4 2 and 3 200 115 260 230 520 300 140 320 280 640 400 160 3-in. Noz. 365 4-in. Noz. 320 3-in. Noz. 4-m. Noz. 100 185 32s 370 650 2 9 5 3 and 4 200 260 460 520 920 300 320 ';65 640 1130 400 3-m. Noz. 650 730 1300 4-in. Noz. 3-in. Noz. 4-in. Noz. 100 i8s 325 370 650 3 11 6 3 and 4 200 260 460 520 920 300 320 565 640 1 1 30 400 4-in. Noz. 650 6-in. Noz. 4-in. Noz. 1300 6-in. Noz. 100 325 730 650 1460 4 1 1 7 4 and 6 200 460 1000 930 2000 300 565 1270 1130 2540 400 650 1460 I.'^OO 2920 28 TABLE OF FLOW OF WATER THROUGH NOZZLES IN MINERS' INCHES Head in Diameter OF Nozzles in Inches. Feet. I I 'A 2 2% 3 3^ 4 20. 6.25 14.0 25.0 39.0 56.0 76.5 100. 25. 7.0 15.6 27.9 43.6 63.0 85.5 1 12.0 30. 7.6s ^l^ 30.6 47.7 69.0 93.7 122.2 35- 8.25 18.5 33.0 51.5 75.2 102.0 132.0 40. 8.85 19.9 35.3 55.1 79.S 108.0 142.5 45. 9.37 21.0 37.4 58.4 84.5 114-5 149.5 50. 9.85 22.15 39.5 61.6 89.0 122.0 158.0 60. 10.8 24.2 43.2 67.5 97.3 132.2 173.0 70. 11.7 26.25 A.7.7 72.9 105.0 142.8 186.2 80. 12.5 28.25 50.0 77.9 II 2.0 152.6 199.5 90. 13.25 29.75 53.0 82.6 119.0 162.0 212.0 100. 14.0 31.45 s6.o 87.3 126.0 171.0 224.0 125. 15.62 H-' 62.5 97.5 140.7 191.5 250.0 150. 17.15 38.5 68.5 106.8 154.0 209.5 274.0 175- 18.6 41.6 74.2 115. 6 163.0 227.0 296.0 200. 19.85 44.5 79.3 123.2 178.0 242.0 316.0 250. 22.1 49.6 88.4 138.0 198.5 270.0 352.5 300. 24.25 54.5 97.0 151. 217.S 296.0 387.0 3SO. 26.1 58.7 104.S 163.0 234.S 320.0 417.5 400. 28.0 62.9 1 1 2.0 174.6 252.0 342.0 448.0 450. 29.8 66.8 118.7 185.0 267.0 361.5 474.0 500. 31.24 70.2 125.0 195.0 281.4 383.0 500.0 550. 32.85 73.8 131.0 205.0 295.0 402.0 524.0 600. 34.3 77.0 137.0 213.6 308.0 419.0 548.0 700. 37.2 83.2 148.4 231.2 326.0 454.0 592.0 800. 39-6 89.0 158.6 246.4 356.0 484.0 632.0 900. 42.0 94-3 167.5 261.8 377.0 513-0 670.0 1000 44.2 99.2 176.8 276.0 390.O 540.0 705.0 GOLD TABLE FOR DETERMINING THE VALUE OF FREE GOLD PER TON (2,000 LBS.) OF QUARTZ OR CUBIC YARD OF GRAVEL Prepared by Melville Atwood, Esq., F. G. S., Consulting Mining Engineer Weight Washed Gold. 4-lb. Sample. Grains Fineness. 780. Value per Oz. Fineness. 830. Value per Oz. Fineness. 875. V^alue per Oz. Fineness. 920. Value per Oz. $16.12 $17.15 $18.08 $19-01 5 grains $83.97 $89.36 $94.20 $99.05 4 67.18 71.49 75.36 79-24 3 50.38 53.6i 56.52 59-43 2 " 33.59 35.74 37.68 39-62 I " 16.79 17.87 18.84 19-81 •9 " 15.11 16.08 16.95 17.82 - .8 " 13.43 14.29 15-07 15-84 •I » 11-75 12.51 13-19 13-86 .6 " 10.07 10.73 11.30 11.88 .5 " 8.40 8.93 9.42 9-90 .4 6.71 7-14 7-53 7-92 •3 !! 5.03 5-36 5-65 5-94 .2 3.36 3-57 3-76 3-96 .1 " 1.68 1.78 1.88 T.98 EXPLANATION OF GOLD TABLE The table on this page furnishes an exceedingly simple method of determining the value of free gold in a ton of gold-bearing quartz, or a cublic yard of auriferous gravel. Take a sample of four (4) pounds of quartz, pulverize it to the usual fineness for horning; wash it carefully by batea, pan, or other means ; amalgamate the gold by the application of quicksilver; volatilize the quicksilver by blowpipe or otherwise; weigh the resulting button, and the value given in the table opposite such weight will be the value in free gold per ton of 2,000 pounds of quartz. Example. — Sample of four pounds produces button weighing one grain, the fineness of the gold being 830, then the value of one ton of such quartz will be $17.87. If the sample of four pounds should produce a button weighing, say, four-tenth of a grain (.4), then the value of such quartz would be (830 fine) $7.14 per ton. GOLD VALUE OF A CUBIC YARD OF GRAVEL A cubic meter is equivalent to 35-3^56 cubic feet. To determine the gold value of a cubic yard of auriferous gravel, the same table can be used. Take a sample of sixty (60) pounds of gravel, pulverize it, and carefully wash it by batea, pan, or otherwise; amalgamate the gold, volatilize the quicksilver; weigh the button, and in column in table, opposite the weight, will be found the gold value of the cubic yard of gravel. Example. — Sample of sixty pounds pioduces button weighing one grain, the fineness of the gold being 780; then the value of one cubic yard of such gravel would be $1.67. This is arrived at by pointing off one point, or dividing the value given in table by 10. If the sample of sixty pounds yields a button weighing five-tenths (.5) of a grain, then the value of the gravel would be — gold being 780 fine — $0.84 per cubic yard. Perfectly pure gold is worth $20.67183 per troy ounce. 29 TROY WEIGHT U. S. AND BRITISH 24 grains, i pennyweight, dwt. 20 pennyweights, . . . i ounces 480 grains. 12 ounces, . . . . . i pound = 240 dwts.=: 5,760 grains. Troy weight is used for gold and silver. SQUARE OR LAND MEASURE U. S. AND BRITISH . 144 square inches, i sq. foot. 100 sq. feet=i square. 9 sq. feet, i sq. yard= 1,296 sq. inches. 305^:4 sq. yards, i sq. rod — 27234 sq. feet. 40 sq. rods i rood= 1,210 sq. yards— 10,890 sq. feet. 4 roods, I acre=i6o rods--4,840 sq. yds. = 43,560 sq. ft. CUBIC OR SOLID MEASURE U. S. AND BRITISH 1,728 cubic inches, i cubic, or solid foot. 2y cubic feet, i cubic, or solid yard. A cord of wood=i28 cubic feet; being 4 ft. x 4 ft. x 8 ft. METRIC MEASURES OF LENGTH BY U. S. AND BRITISH STANDARD Inches Feet Yards Miles Millimeter,* . . .039370 .003281 Centimeter,! • • .39370428 .032809 Decimeter, . . 3.9370428 .3280869 .1093623 Meter,** . . . 39.370428 3.280869 1.093623 Decameter, . . 393.70428 32.80869 10.93623 Hectometer, ) Road Measures 328.0869 109.3623 .0621375 Kilometer, >- 3280.869 1093.623 .6213750 Myriameter, 1 32808.69 10936.23 6.213750 * Nearly the 1-25 part of an inch. f Full j^ inch. ** Very nearly 3 ft. 3^ ins., which is too long by only i part in 8616. METRIC WEIGHTS REDUCED TO COMMON COMMERCIAL OR AVOIR WEIGHTS, OF Centigram, Milligram, Decigram, Gram, . . POUND = i6 OUNCES ,OR 7,000 GRAINS Grains .15432 .015432 1.5432 15.432 Decagram, Hectogram, Kilogram, Myriogram, Quintal,* Tonneau; Millier; or Tonne, Pounds. Av. .022046 .22046 2.2046 22.046 220.46 2204.6 The gram is the basis of French weights; and is the weight of a cubic centimeter of distilled water at its maximum density, at sea level, in latitude of Paris; barometer, 29.922 inches. RUSSIAN FOOT: Same as U. S. or British foot. SACHINE = 7 feet. VERST=5oo sachine= 3,500 feet=i,i66 2-3 yards=:.6629 mile. POOD = 36.i44 pounds avoirdupois. SPANISH THE CASTELLANO of Spain and Colombia, for weighing gold, is variously estimated from 71.07 to 71.04 grains. At 71.055 grains (the mean between the two) an avoirdupois, or common commercial ounce, contains 6.1572 castellano; and a pound avoirdupois contains 98.515. Also, a troy ounce=6.7553 castellano; and a troy pound=8i.o64 castellano. Three U. S. gold dollars weigh about r.i castellano. THE SPANISH MARK, or marco, for precious metals, in South America, may be taken in practice, as .5065 of a pound avoirdupois. In Spain, .5076 pound. In other parts of Europe it has a great number of values; most of them, however, being between .5 and .54 of a pound avoirdupois. The .5065 of a pound = 3545j^ grains; and .5076 pound=3553.2 grains. I marco = 5o castellanosT=40o tomine=48oo Spanish gold-grains. THE ARROBA has various values in different parts of Spain. That of Castile, or Madrid, is 25.4025 pounds avoirdupois; the TONELADA, of Castile, = 2032.2 pounds avoirdu- pois; the QUINTAL=ioi.6i pounds avoirdupois; the LIBRArri.oi6i pounds avoirdupois; the CANTARA of wine, etc., of Castile, = 4.263 U. S. gallons; that of Havana = 4.i gallons. The VARA, of Castile, = 32. 8748 inches, or almost precisely 32% inches; or 2 feet, 8J4 inches. The FANEGADA of land, since 1801,=: i. 5871 acres=r69i34.o8 square feet. Tne FANEGA of corn, etc. ,= 1.59914 U. S. struck bushels. In California, the VARA by Iaw= 33.372 U. S. inches; and the LEGUA=: 5,000 varas; or 2.6335 U. S. miles. 30 INDEX PAGE Our Advantages 3 Types of Dredges 4 Elements of Dredges 5 Bucket Line 6 Ladders 7 Tumblers 7 Screen 10 Gold Saving Tables and Sluices .... 10 Stacker 11 Pumps II Winch 12 Hull 14 Steel Gantries, etc 14 Engines 15 Boilers 16 Electrical Equipment 16 Our Ideals 17 Export Work 18 Comparison with Foreign-built Dredges . 18 Erecting Dredges complete 19 Water or Steam Power Plants 20 Sizes and Capacities 20 Dredging 21 Dredging Conditions 22 Dredging Possibilities 23 Dredging Dry Placers ....... 24 Historical 25 Useful Tables 26, 27, 28, 29, 30 31 IS PRESS vnu V