. -TLfU-JV REESE LIBRARY OF THK JNIVERSITY OF CALIFORNIA. - Deceived JUN 14 1893 , l8g . ^Accessions No'f5~/t>'' . Class No. TALL CHIMNEY CONSTRUCTION. TALL CHIMNEY CONSTRUCTION. flractal feato an OF TALL CHIMNEY SHAFTS, CONTAINING DETAILS OF UPWARDS OF EIGHTY EXISTING MILL, ENGINE- HOUSE, BRICK WORKS, CEMENT WORKS, AND OTHER CHIMNEYS IN ENGLAND, AMERICA AND THE CONTINENT, CONSTRUCTED IN BRICK, STONE, IRON AND CONCRETE. BY ROBERT M. BANCROFT it (Past President Civil and Mechanical Engineers'* Society, London, England), AND FRANCIS J. BANCROFT (Assistant Municipal Surveyor). MANCHESTER : JOHN CALVERT, 99, GREAT JACKSON STREET, HULME, AND 100, KING STREET. LEWES : FARNCOMBE AND Co., "EAST SUSSEX NEWS" OFFICES. 1885. {Entered at Stationers' Hall.] LEWES FARNCOMBE AND CO., PRINTERS. / T~ A HE Authors wish to state that it has been their aim -*- throughout to place before the reader a practical treatise, and for that purpose have collected information respecting upwards of eighty chimney shafts brick, stone, iron and concrete from various parts of Great Britain, the Continent and America, and they take this opportunity of thanking their numerous friends for the uniform courtesy with which their enquiries have been answered. In January, 1878, a paper on Chimney Construction was read by Mr. R. M. BANCROFT, Past President, before the Civil and Mechanical Engineers' Society, and the interest with which it was received led him to further his investigations. In December, 1883, a paper on the same subject was again read before the Civil and Mechanical Engineers' Society, by the Authors, the information and examples having been greatly increased. Since that date the work has been added to, revised and further illustrated. ILLUSTRATIONS, Plate x. No. 1 Draught. 2 Wind Pressure. 3 Stability. 4 7 Port Dundas, Glasgow. Section at Foundation, Scaffolding, Brick Coping. 89 St. Rollox, Glasgow. Sectional Plan and Elevation at Foundation. Plate 2. 10 Barmen, Prussia, Messrs. Wessenfields' Shaft. Cutting Bricks for Straightening. II 15 Carlisle, P. Dixon. Sectional Elevation, Plan, Elevation at base of Shaft, Cap at top. 1 6 Greenhithe, I. Johnson. Sectional Elevation at base. Plate 3. 17 Dundee, Cox Brothers. Elevation of Shaft. 1 8 Bradford, Messrs. Lister, Manningham Mills. Part Elevation. 19 20 West Cumberland Haematite Works. Plan and Elevation at base. 21 Lancaster, Storey Brothers. Part Elevation and Section at top. Plate 4. 22 30 Bradford, Newlands Mills. Plate 5. 31 33 Dovercourt, Pattrick & Sons. Elevation at base and Cross Sections. 3436 Northfleet, Messrs. Gostling. Sectional Elevation, Cross Section and Plan of Cap. 3738 U.S.A., Cleveland Rolling MiUs. Wrought Iron Shaft, Elevation and Cross Section 39 Prussia, Georgs-Marien Iron Works. Section. Plate 6. 40 43 Dundee, Dens Works. Part Elevation, Vertical Section and details of Cap. 4447 U.S.A., Falls River Print Works. Part Elevation, Vertical Section, details of Cap and Cross Section. iv. Illustrations. Plate 7. No. 48 53 Huddersfield, Brooks & Son. Half Plan at Foundation, Sectional Elevation at base, Sectional Plan at Flues, Cross Sections and Plan at top. 54 59 U.S.A., Philadelphia Railway "Workshops. Elevation, part Vertical Section, Cross Sections and detail of Cap. Plate 8. 60 64 U.S.A., Yale Lock Co. Elevation at base, Vertical Section, Cross Sections and Plan at top. 65 68 London, South Metropolitan Gas Works. Vertical Section, Elevation at top and Cross Sections. Plate g. 69 Lewes, Messrs. Harvey, Brewers. Elevation of Octagonal Shaft. 7071 Sunderland, River Wear Commissioners. Elevation and Vertical Section of Concrete Chimney. 72 73 Middlesboro'. Taking down Chimney, Vertical Section and detail Joint of Air- tight Spout. Plate io. CAPS. 74 Salford Sewage Works 156' high 75 London, London and North Western Railway Goods Station 150' ,, 76 Eastbourne Water Works 150' 77 London, Messrs. Gordon, Brewers 100' ,, 78 Frankfort, Messrs. Moulson & Co 92^' ,, 79 London, Great Northern Railway Goods Yard 9 1 !' 80 Kent Water Works 90' 8 1 Derby, Great Northern Railway Engine House 90' 82 Hastings, Water Works 84^' INDEX. Page iii. Illustrations (List of). GENERAL REMARKS. 9 Foundations, Weather, Brickwork, Bond, Expansion, Supervision, Caps, Cornices, &c. 12 Minimum Heights of Shafts. 13 Metropolitan Board of Works Regulations. TESTS AND STRENGTH OF MATERIALS. 14 Bricks, Mortar, Stone and Portland Cement. 26 Draught. 30 Stability. Height from TloJliT EXISTING CHIMNEYS. feet. When Built. 33 454 Glasgow, Port Dundas Jf. Townsend 1857-8-9 37 436^ Glasgow, St. Rollox Tennant dr* Co. 1841-2 40 367 Lancashire, Bolton Dobson 6^ Barlow 1842 41 331 Prussia, Barmen Wessenfield dr 3 Co. 1867-8 45 329 Edinburgh Gas Works 47 315 Huddersfield . . . Brooks & Son, Fire Clay Works 48 312 Smethwick Adam's Soap Works 1835 49 300 Carlisle P. Dixon &* Sons 1835-6 50 300 Bradford Mitchell Bros. 51 300 Halifax J. Crossley & Sons 1857-8 51 297 Kent, Greenhithe /. C. Johnson 53 282 U.S.A., Lowell, Mass. . . Merrimack Manufacturing Company 1882 54 282 Dundee Cox Bros. 56 280 France, Creusot Schneider 6^ Co. 1869 58 259 Lancashire, Barrow-in-Furness . . Hcematite Iron and Steel Works 1865 58 255 U.S.A., Manchester, New Hampshire . . . Amoskeag Manufacturing Company 1883 59 256^ Bradford, Manningham Mills Lister dr* Co. 1872-3 60 250 West Cumberland H&matite Iron Works 63 250 Lancaster Storey Bros. 1876-7-8 65 245 Cheshire Connahs Quay Chemical Company 65 240 Bradford Newlands Mills (fell down) 1862-3 68 233 U.S.A., Lawrence, Mass Pacific Mills 1873 69 230 Harwich, Dovercourt Pattrick dr* Sons 1883 70 223! Woolwich Arsenal Shell Foundry vi. Index. Height from ground line to top in Page feet. When Built. 71 220 Northfleet ........ J. C. Gostling & Co. 1873 74 217 U.S.A., New York .... Steam Heating Company 75 210 Dewsbury .......... Olroyd dr* Sons 1869 76 210 Lanarkshire ....... Coltness Iron Works 76 190 U.S.A., Cleveland . . . Ohio Rolling Mills Company 1881 78 186 Sheffield, Deepcar ......... Fox & Co. 1866 78 180 Bury Corporation Works ........... 1881 79 1 80 Bradford Corporation Works .......... 1880 1 80 120 [ 1857 80 ( 102 \ Prussia, Georgs Marien ............ 1870 102 102 174 ) 8 1 \ 135 \ Dundee, Dens Works ....... Baxter Bros. I02f ) 84 177 Crossness . .' . . . Metropolitan Board of Works 1863-5 85 170 Woolwich ........... Gun Factory 85160 U.S.A., Massachusets . . . Falls River Print Works 87 160' Worcester Brick Works ..... W. D. Barker 1869 88160 London, Nine Elms Cement Works . . Francis & Co. 1878 89 160 Mexico Cotton Factory ............ 90 158! Russia, Mr. Shekolden's Paper Mills ....... 1874 91 158 Abbey Mills Pumping Station . . Metropolitan Board of Works 1867 92 156 Salford Corporation ............. 1883 93 _ I5 o U.S.A., East Newark, N.J., Mile End Spool Cotton Mill 95 150 Eastbourne Waterworks ........... 1881-2 95 150 London, Bermondsey .... Prockter & Bevington 1881-2 96 150 London, Broad Street Goods Station, City, London and North- Western Railway .......... 1867 97 _ I5 o Huddersfield ......... Brooks & Sons 1878 98 140 Great Yarmouth ........ E. Lacon &* Co. 1838 i 99 1 34 J. Glasgow ......... McFarlane & Co. j 99 133 Oldham .... Carbon Fertilizer Manure Company 1874 100 127 Great Yarmouth, Silk Crape Company . Grout &" Co. 1829-30 101 12 if U.S.A., West Philadelphia Shops, Pennsylvania Railroad 102 I2o Woolwich Arsenal ............. 1 02 1 20 London, Clerkenwell Road ..... Reid & Co. 103 120 U.S.A., Stamford, Connecticut, Yale Lock Manufacturing Company 1881 107 | x * 1 Birmingham, Hansworth . . . . Phcenix Bolt Works 1871 107 io8| Surrey Commercial Docks ........... 1883 108 1 08 London, South Metropolitan Gas Works ...... 1862 109 107 Tamworth Water Works ........... 1880 no 105 Lincolnshire, Boston ....... Flour Mills 1869-70 in 100 London, Caledonian Road ... A. Gordon &* Co. 1867 112 loo Doncaster Local Board ............ 113 96^ London, Farringdon Street, City, Great Northern Railway 1880 Index. vii. Height from ground line to top in Page feet. When Built. 114 91 London, Drummond Road . . . Peak, Frean & Co. 1866 Manchester Thos. Hoyle & Sons Bradford, Great Northern Railway 1875 Kent Water Works . . 1879 Loughborough G. Tucker <5r" Son 1873 London, Fulham . . . West End Laundry Company 1883 Hastings and St. Leonards Electric Light Company . . 1882-3 Tunstall Ravensdale Iron Works London, Bermondsey G. M. Hammer 1882 Lewes Harvey & Sons 1881 Sunderland, River Wear Commissioners - Middlesboro', Taking Down Chimneys ...... WROUGHT IRON CHIMNEYS. STRAIGHTENING SHAFTS. 125 Bingley near Bradford. 126 132 Pitchcombe, Gloucestershire. Matthew & Sons Chemical Works 1862 See also p.p. 36, 43, 64 and 67. FALL OF SHAFTS. 127 165 Oldham A. Stott & Sons 1873 128 100 Glasgow Waggon Works 128 105 Bury Eaton Vale Bleach Works 129 Sheffield and Neighbourhood, 10 Chimneys. See also Gostling's and Newlands Mills Chimneys, p.p. 71, 65 BLOWING DOWN SHAFTS. 130 95 Dublin .... Ncrth Lotts Glass Bottle Company 1820 131 406 Warrington Muspratfs Chemical Works MOVING SHAFTS. 132 78 U.S.A., Maine Cabot Company's Cotton Mill. CLIMBING CHIMNEYS. 132 Apparatus employed and instances of Shafts ascended. VENTILATING SHAFTS. 134 For Sewer Ventilation, Towns where adopted. GENERAL. 135 An Awkward Dilemma. 136 A Novel Dinner Party. TALL CHIMNEY CONSTRUCTION. References : W. J. M. RANKINE, R. WILSON, THOMAS Box, R. ARMSTRONG, HOLYROYD SMITH, P. CARMICHAEL, R. ANDERSON, GRAHAM SMITH, D. KIRKALDY, H. FAIJA, J. WAUGH. CHIMNEYS are constructed principally for two purposes. Firstly, to create the necessary draught for the com- bustion of fuel ; Secondly, to convey the noxious gases to such a height that they shall be so intermingled with the atmosphere as not to be injurious to health. A chimney shaft, when in work, contains a tall column of heated air, which, being lighter than the outside atmosphere, is forced upward by a corresponding column of atmospheric air pressing into the entrance of the furnace ; thus a displacement of hot air is constantly being effected, and its place filled by normal air forcing itself through the furnace of the boiler, which air is in its turn heated and displaced. The column of atmospheric air and the column of rarefied air in the chimney are somewhat like a pair of scales, or the two ends of a lever of which the boiler is the fulcrum. Foundations. In building large chimneys one of the most important points is the construction of the foundation. Very much will depend, of course, upon the nature of the ground. When on solid rock, it is only necessary to excavate to such a depth that the heat of the gases will not materially affect the natural stone, and to a depth sufficient to allow the necessary spreading of the base. In many instances, however, chimney stacks have to be built near rivers and on sites where the upper strata are of alluvial clay or made ground, and it is necessary to carry the foundation deep down until a stiff clay, hard sand, or rock bottom is reached. This frequently entails excavation 25' or 30' deep or even more, and it is not only requisite that the foundation should be large enough to carry the super- incumbent weight, but also that it should be of such an area B io Tall Chimney Construction. that it will not allow the base to be forced into the yielding- ground. These deep foundations are usually constructed 01 concrete. In some cases piles are driven in to form the founda- tion, as, among others mentioned further on, in a brick chimney erected at Boston, England, and in an iron chimney constructed at Ohio, U.S.A. This piling is a measure on which the engineer must decide upon the advisability of using, so as to economise material without risking unequal subsidence, which cannot be too carefully guarded against; and, in fact, it is the practice in the erection of tall stacks to construct the foundation and pedestal, if any, and allow them to stand some considerable time before proceeding with the shaft proper, in order that the work may set, and any slight settling take place, before a great weight is built upon it. As a remarkable instance of the general settlement of the foundation of a shaft, we may mention a chimney which was built by Mr. Clegg, at Fulham, over a quicksand, in which an iron rod sank to a depth of 15' with little more than its own weight as pressure. During the erection the concrete foundation sank bodily i' 4^" without cracking the shaft or causing it to deviate from the perpendicular. From this it will naturally follow that in all cases the ground at the foundation should be equally resistant, or unequal settling will take place, as in the disastrous case of the Newland's Mill chimney, Bradford, as hereinafter detailed. Some of the pressures exerted upon the foundations are given under the respective descriptions of the chimneys, most of the other pressures can be worked out from the data supplied. Weather. Shafts should be erected in the summer months; on no account should the work be proceeded with in frosty weather. Progress. Shafts should be constructed at the rate of from 2' to 2\ f in height per day, but of course the progress is largely dependent upon the size of the shaft being erected ; the taller the shaft the more care should be exercised in allowing the mortar to set, and the foundations to gradually take and settle down to the weight of the superincumbent mass. In Lancashire large shafts are built about half their ultimate height, and then left six months to consolidate before completion. Brickwork^ &c. The bricks used should be picked stocks, hard and sound, with square sharp edges, thoroughly burnt and General Remarks. n of uniform thickness. They should be well wetted with water before being laid. The joints of the brickwork should be well flushed up with mortar every course; this is much to be preferred to grouting every 2nd or 3rd course. The grouting being fluid mortar becomes porous and possesses little adhesive power, as the water evapo- rates. Grouting should, therefore, be discountenanced. The brickwork should be laid in mortar for the most part because cement is destroyed by a strong heat. Any 4^" work at the top should, however, be constructed in good cement. With so thin a wall the heat is rapidly carried off by the external air, and in such a case the cement will be uninjured. Ordinary stock bricks will withstand a heat of 600; where a heat is anticipated greater than this, fire-bricks should be used. Bond. In large factory chimney shafts the longitudinal tenacity which resists any force tending to split the chimney is of more importance than the transverse tenacity ; therefore, in these structures, it is advisable to have, say, three or four courses of stretchers to one course of headers. In some circular stacks an uniform header bond is adopted for the outside courses of the brickwork. This is a practice condemned by some authorities, but is almost unavoidable in the construction of small circular shafts, unless purposely made bricks are used, owing to the sharp curvature of the work ; in shafts having large diameters it should never be employed. The longitudinal strength of a shaft is much increased by building in hoop-iron every few courses, and is a practice often adopted and to be commended. Care must, however, be taken to fix a good lightning conductor to a shaft thus constructed, as the stack would form a great attraction to the electric fluid. Expansion. Chimney shafts should not be tied to any other work or buildings, and should have no woodwork or anything fixed to them, on account of the settlement that takes place after the shaft has been erected, the expansion caused by the heated gases, and the oscillations caused by wind. Supervision* The shafts should be plumbed and levelled every 3', or oftener, so as to obtain a regular batter, and keep the stack erect ; and care should betaken that in angular shafts the quoins are built without twist. 12 Tall Chimney Construction. Caps, Copings and Cornices. The stone coping or cornice of a chimney will seldom require more to hold it together than two good cramps across each joint ; they should be of copper, or double dove-tailed slate dowels. On no account should iron cramps be used, as they will oxidise and burst the stone. Heavy and large caps are often the source of great danger, inconvenience and expense (see Brooks & Son's Chimney, page 48], as the cap at top in a gale of wind acts upon the shaft as a weight at the end of a long lever. The cap, when finished, should be a complete whole, or so bound together that the joints cannot open, and be so proportioned that the centres of gravity, of its respective component parts, all fall within the outer circle of the shaft on which they rest, and the cap should be designed so that the wind striking against it is deflected upwards. Minimum Height. The minimum height of chimney shafts allowed by many Town Improvement Acts, as in Manchester, Bradford, Leeds and other towns, is 90'. FURNACE CHIMNEY SHAFTS. METROPOLITAN BOARD OF WORKS REGULATIONS. Every chimney shaft, for the furnace of a steam boiler, brewery, distillery, or manufactory, shall be carried up through- out in brickwork and mortar, or cement, of the best quality. Every furnace chimney shall be built upon a bed of con- crete, to the satisfaction of the District Surveyor. The base of the shaft shall be solid to the top of the foot- ings, and the footings shall spread equally all round the base by regular offsets to a projection on both sides equal to the thickness of the wall at the base. The width, measured externally, of a furnace chimney shaft at the base, or at that portion immediately above the footings, shall be as follows : If square on plan, at least one-tenth of the total height of the shaft. If octagonal on plan, at least one-eleventh of the total height of the shaft. If circular on plan, at least one-twelfth of the total height of the shaft. Every furnace chimney shaft shall have a batter of 2j" at least in every 10' of height, or i in 48. The brickwork shall be at least 8J" in thickness at the top of the shaft and for not exceeding 20' below, and shall be in- creased at least 4!" in thickness for every 20' of additional height measured dow r n wards. No portion of the walls of a furnace chimney shaft shall be constructed of fire-brick, and any fire-brick lining to be used must be in addition to the thickness of, and independent of, the brickwork. Every cap, cornice, pedestal, string-course, or other varia- tion from plain brickwork, shall be in addition to the thickness of brickwork prescribed by the foregoing rules, and no cornice shall project more than the thickness of the brickwork at the top of the shaft. TESTS AND STRENGTHS OF MATERIALS. {Except where otherwise stated, made by D. Kirkaldy, London.) BRICKS. MR. J. C. EDWARDS' BRICK WORKS, RUABON. The following are results of experiments to ascertain the resistance, to a gradually increased thrusting stress, of twelve bricks manufactured at these works : Description. Dimensions, inches. Base area, square inches Stress in p< Cracked slightly. Hinds when Cracked generally. Crushed, steel-yard dropped. Red Brick (no 3-10 . 875 X 4*28 37-45 336,050 446,700 461,500 recess) 5, J 3"!3 875 X 4-26 37-27 225,300 39 r ,5 455. ioo 3-10 . 8-80 x 4'3 37-84 358,500 408,100 442,950 3-19 . 8-78 x 4-26 37-40 215,100 236,250 376,900 3-10 . 875 X 4*28 37-45 232,500 286,100 358,600 Blue Bricks (no recess) 3-15 873 x 4-29 Mean . . . . Lbs. per square in Tons per square fc 37-45 168,250 223,500 271,300 37-47 255.950 333.025 394,391 ch . . ot . V 6,830 8,887 10,525 439-2 571-5 676-8 3-02 . 8-99 X 4'37 3-00 . 8-97 X 4-34 39-28 38-92 307,100 261,900 385,100 338,100 388,050 377,030 ,, 3-03 . 9-00 X 4*37 39-33 148,300 246,250 344,100 3-05 . 9-00 x 4-38 39H2 181,800 251,500 327,700 M ' 3-04 . 8-97 X 4-33 38-84 153,000 286,100 310,100 3-01 . 8-95 x 4-36 Mean . . . . Lbs. per square in Tons per square fc 39-02 258,600 300,200 302,050 39-13 218,450 301,208 341,505 ch . . )0t . . 5.582 7,697 8,727 358'9 494-9 561-2 Bedded between pieces of pine f" thick. Tests and Strengths of Materials. HIGH BROOMS BRICK COMPANY, TUNBRIDGE WELLS. The following table gives the average pressure in pounds on a single brick, each result being the mean of six tests : Description. Base area square inches Slightly cracked. Ibs. Generally cracked. Ibs. Crush'd, steel yard dropped. Ibs. Tons per square foot. Sewage Bricks (dark) . . 39'87 170,847 226,853 253^98 408-7 Do. do. (light) . . 39-99 136,933 209,905 232,863 374-5 Brindle do. (dark) . . 36-97 162,497 211,190 296,790 516-2 Do. do. (light) . . 36-52 94,922 141,688 235585 414-8 Blue do. .... 40-64 188,125 250,95 332,043 525-4 Wire-cut do 40-80 105,658 157,927 232,337 366-2 Common Building . . . 37'94 74.987 97,070 118,825 201-4 The samples were bedded between pieces of pine f " thick. STAFFORDSHIRE VITRIFIED BLUE BRICKS. Size of bricks, 2 '55" x 9*03" x 4*30". Mean base area of six samples, 39*06 square inches* All samples bedded between pieces of pine J" thick. J. HAMBLETT, West Bromwich. Cracked slightly. Stress in Ibs. when Cracked generally. Crushed, steel-yard dropped. 187-1; 34.1-6 440*68 2nd ,, 164.'"? 306-0 4O4*27 3rd jr-j'O 291*0 206*16 4th 148-2 28^*4 387*82 t;th 124*6 24.4* I 2.82-7S 6th 115-8 2l6'2 O Ul6 /O 266" 24 JVU ^ Mean . I48*O 280-7 7Q7-8 1 ? jy/ j Equal to Ibs. per sq. inch. Tons per sq. foot 3-812 245-1 7-186 462-I IO-I85 654-9 i6 Tall Chimney Construction. The following table gives results of tests made during the erection of Blackfriars Bridge : BRICKS IN PIERS FOUR COURSES HIGH. Description of bricks. Size of pier in bricks. Mortar. Failing slightly, tons per foot super. Entirely crushed tons per foot super. Common Stock, recessed . i|X ii Lias Lime. 17 27 Do. do. . . }> H 21 30 Red bricks, machine made J 20 40 Do. hand made . . Gault Roman Cement 20 24. 3& CQ Do ... I X I r V }> J> J> 3-20 x 9*14 X 4*5 >> > > } j> > 4I-I3 > ii > 45,680 45,590 38,760 36,180 86,220 79,775 77830 70,960 9I,l8o 90,320 89,640 85,820 4^552 78,696 89,240 Lbs. per square Tons Builders,recessed top and bottom 1,010 65 1,913 123 2,170 139-5 foot 3-20 X 9-3 X 4-5 41-85 - 40,960 39,280 36,490 33>54Q 97,240 95, 2 7o 87,382 81,180 113,220 106,530 101,202 95,840 36,490 87,382 101,202 Lbs. per square Tons 872 56-i 2,038 134-2 2,418 rSS'5 foot . Bedded between pieces of pine " thick and recesses filled with cement. Tests and Strengths of Materials. c/) s PQ S * ^ - a q c l"~l C/) O S ll r& C S % 3 g PQ 5 , -i ^Q I -g I ^ co O r^ * . 1-H 8 ffl ,3 M g .^ o> bo -" r^Q CO PQ a ^ ?n O w co J8 C\3 (j ft J 1 1 sfH ! I CJU U CJ CJ PQ o wo w 9 R S> rj LT> aO O Q *-O ^O O HH O O X 88 8 8 888 8 - a -3 2, 3, 4, &c., indicating the order in which the brickwork was removed. When division i was broken out it was replaced by thinner bricks covered with "terrass" mortar. After this the two divisions marked 2 were broken out and replaced by thinner bricks ; then the two divisions marked 3, and so on until one- half of the whole course had been exchanged. Purposely-made flat shovels with long handles were used to lay the bricks, which had to be placed near the inside of the chimney. A side space of 5" was left between the newly- laid bricks and the old ones of the next division, so as to enable the workmen to break out the latter with greater facility. The width of each single division was 2' to 2^'. The masonry directly above was sufficiently dry not to give way 44 Tall Chimney Construction. when a course of that width was removed from below it. The replaced bricks were thicker near the points A and c, so that the difference was greater in the middle, and gradually less toward the extremities A and C. As soon as the slit reached these points the chimney began to move, and by slight oscillations slowly settled down on the new layer of bricks. The time occupied in settling by oscillation at each substituted course varied from 18 to 36 hours, according to the widths of the slits, which were different in the various cuts performed. The oscillations were the greater the higher the cut. At the highest cut, loo-ft. from the top, the oscillations frightened the masons, and they left the work. The slit became alternately wider and narrower by three-quarters of an inch. This seemed to prove the elasticity of the structure. The four cuts made were as follows : ist .... 4' above pedestal greatest width . . . . f 2nd .... ioo' . . . . ii 3rd .... 140' . . . . ij 4th .... 191' . . . . if After the completion of this work the chimney continued during several weeks to settle slightly in the direction opposite to its former inclination. This circumstance had to be carefully considered beforehand, or else the slits would have been made too wide, and have produced an inclination in the opposite direction. A severe storm on the 6th and yth Dec., 1868, which over- threw several chimneys in the neighbourhood, did not affect this one. The result of the straightening operation described above was quite satisfactory. The heights of the upper cuts were reached as follows: Standing on a platform the masons made a number of holes into the exterior wall of the chimney 4' above the platform on w r hich they stood. Into these holes the ends of iron bars were fixed, and boards secured to them so as to form another platform. Standing then on the latter they fixed another plat- form 4' higher in the same way. Every second platform was removed, so that the remaining ones were 8' apart ; they were then joined by ladders for the workmen to ascend. This method of straightening is only practicable when the chimney has a considerable diameter, and when the mortar is sufficiently dry not to give way under pressure of the bars and platforms. Detailed Examples of Existing Shafts. 45 In Dec., 1868, a chimney was straightened at Duisburg by the method just described, but as the diameter was not so great as that at Barmen, and as the mortar was soft, a wooden scaffold was erected round the shaft to reach the upper points, which required cutting. The breaking out and replacing bricks could not be done there in divisions wider than 5 to 10 inches, as the upper masonry not being dry would have settled down. When the chimney was straight a further settling down towards the side of the cuts was prevented by driving iron wedges, covered with mortar, into the slits. EDINBURGH GAS WORKS, CHIMNEY. Designed by Mr. MARK TAYLOR, Engineer to the Company. Mr. GEO. BUCHANNAN, C.E., and Prof. GORDON, of Glasgow, were consulted. Builders, Stonework . . Mr. JAMES GOWAN, of Edinburgh. Brickwork . . Mr. JAMES Bow, of Pollocksfields, nr. Glasgow. Description. Square stone pedestal, circular brick shaft. Dimensions, Stone foundation under ground 6^' Part of base ,, ,, 6' Stone pedestal above ,, 65' Brick shaft 264' Total height from foundation to top 34 1 J' Height from ground line to top 329' Foundation. Stone. 40|' sq. X 6|' deep. The distributed pressure on the bottom of foundation per square foot = nearly 2\ tons. Pedestal. Stone, 30' sq. at ground line. 27f top. 22^' internal diam, at bottom. 2o| top. This was built during the summer, at the end of which the works were suspended until the following year. 46 Tall Chimney Construction. Brickwork. Commenced and finished in the summer follow- ing the erection of pedestal. OUTER BRICK SHAFT (circular). Outside diam. at bottom ... 26' 3" Inter. ... 20' 5" Outside diam. at top . . . 15' o" Inter. ,, ... 12' o" This was built up in five steps as follows : 1st section 35' high . . . 3| b. rr 35" 2nd 40' ... 3 =30" 3rd 48' . . . 2\ = zs" 4th 58' ... 2 =20" 5th 83' . . . if =15" 264' total. The greatest pressure on any part of the work comes at the lowest section, where it amounts to about 8 tons 2 cwt. per square foot. INNER BRICK SHAFT (circular). This is distinct from the outer shaft and is 90' high with 1 3' internal diameter throughout, and was built in four steps, viz. : 1st section 14' high 35" thick. 2nd 6' 30" 3rd 30' 25" 4th 40' 20" 90' total. The thicknesses include a lining of fire-brick 10" thick for 20', and 5" thick for remaining 70'. Materials. The weight of, is about 3,700 tons. Cost. Total was ^4,63 7. Lightning Conductor. Solid copper rod -J-" diam. Stone. The stones used in the foundation are Cragleith, Humbie arid Hailes, which before use were tested by Mr. Buchannan and Mr. James Gowan. The tests were made in a most careful way by crushing cubes of i" square. RESULTS OF TESTS. Cragleith .... crushed at 315 tons per sq. ft. Humbie .... ,, 240 ,, ,, Hailes 225 A second test of Cragleith showed that before being crushed to powder it sustained a pressure of 440 tons per square foot. The appearance, after fractures of the different cubes, was that of a pyramid or wedge, and this led Mr. Gowan to assert Detailed Examples of Existing Shafts. 47 that if the cubes were enlarged a greater increase of strength would be gained, and further, that if the pressure were vertical to the line of cleavage a greater resistance would be obtained, so that such a stone as Hailes, which is a laminated stone, would increase in strength according to its surface more in proportion than that of a liver rock stone such as Cragleith. This led to discussion and further tests, the result being that with a 4" cube from Hailes quarry the resistance was = to 567 tons per square foot. Bricks. These were supplied by Mr. Livingstone, of Porto- bello Brickworks, and were tested with the following results : Crushing weight Crushing weight Description of specimen. Length. Breadth. Thickness. Weight, on ea. brick. per sq. ft. ins. ins. ins. Ibs. tons. tons. Extra size and quality 10 5 3 lof 153 440 Do. do. 9j 4f 2| 9/ 6 - 140 448 Repairs. In May, 1874, a " Steeple Jack" was engaged to examine the state of shaft. Recourse was had to kite-flying to fix at top a rope by which the man could draw himself up, to the free end of which a couple of 56-lbs. weights were attached. It was found that the stack near top had been split in several places by lightning and iron hooping was necessary. MESSRS. EDWD, BROOKS & SONS, FIRE CLAY WORKS, HUDDERSFIELD. Engineer, ROBERT MORGAN ; Builder, JOHN STOCKS. Description. Octagonal brick panelled pedestal, with stone mouldings ; circular brick shaft. Dimensions, Height from foundation to top 330' o" ground line 315' o" ,, of pedestal 70' 6" Outside measurement above plinth 27' o" Inside 15' o" Outside diam. at top under cap 12' o" Inside 9' o" Outside top of pedestal 20' 4" Inside 14' o" Foundation, Concrete, 3' deep, 36' square. Ragstone footings 36' ,, Brick 35' Stepped to . .31' ,, at ground line. 48 Tall Chimney Construction. Materials, 144 cu. yds. . concrete. 2452 ft. . ragstone footings. 3341 . ashlar. 2227 ,, yds. . brickwork. Inner Shaft. An inner shaft is constructed for a height of 150', divided at base with a wall 60' high, to prevent baffling of the draughts. Round this inner shaft is a cavity which is supplied with cold air at the base. Duty. The chimney now serves two boilers, 1 7 kilns 22'diam. Cap. The original cap was a large and overhanging one, and caused the owners much trouble in consequence of many of the stones being blown down, and others being decayed by the action of the acids emitted from the chimney. The whole of the cap was at last removed and built up with purposely-made fire-bricks. The firm estimate that the original cap in its erection and removal cost at least ^700, and from their experience are convinced that no stone should be used at top, any over- lapping to be gradually formed by hard burnt radiated fire-bricks. MESSRS. ADAMS' SOAP WORKS CHIMNEY, SMETHWICK, NEAR BIRMINGHAM. Designed by Mr. BUCKLE, Soho, Birmingham. Description. Circular brick shaft, erected 1835-6. Dimensions, Height from foundation to top 326' 10" ground 312' o" Outside diam. at ground surface 27' 2" Inside 15' 2" Outside top 5' 6" Inside 4' o" Weight. Brickwork, 2,000 tons ; concrete, sand and lime, 150 tons. Bricks. The firm state the bricks used were of large size, and weighed 4 tons per 1,000. The total number of bricks used in shaft was 500,000. Building Operations. The chimney was commenced in the autumn 1835, an d allowed to stand during the winter and was finished in Sept. or Oct., 1836. At the time of its erection this Detailed Examples of Existing Shafts. 49 shaft was the highest in the kingdom. The builder who began the work felt alarmed when the shaft had been erected about half its height, and the firm had to finish it themselves. Lightning Conductor. This shaft has been five times struck by lightning, once during the building when the chimney had reached about 200' in height, and four times since its com- pletion. No very serious damage was done but once, when perhaps the electric fluid was aided by the lime having been abstracted from the mortar by the action of the hydrochloric acid in the escaping gases. The owners were then compelled to take down a portion of the top. These four strokes all happened after the lightning rod had been eaten away at the top by the hydrochloric acid, the remainder of the rod, however, being perfect. The rod is formed of " iron, and being eaten down only a few feet from the top may have had the effect of diminishing the force of the lightning. The conductor has several times been renewed, but the action of the acid was so rapid that it has soon been destroyed at the top, where it is exposed to the action of the escaping gases. In consequence of the rod so soon being eaten away, the firm, about 1871, had the conductor coated with platinum, with very favourable results. A few years ago about 30' more of the shaft were removed from the top by Mr. Frith, builder, of Coventry, who commenced fixing his tackle for the purpose by kite-flying, the chimney being in use all the time. The total height is now about 250' above ground. Cost, ^1,700. MESSRS. P. DIXON & SONS COTTON FACTORY, SHADDONGATE, CARLISLE. Figs. II, 12, 13, 14 and 15. Architect, R. TATTERSALL, Manchester ; Builder, RICHARD WRIGHT, Carlisle. Description. Octagonal brick; built Sept. nth, 1835 Oct. 25th, 1836. Dimensions, Height from foundation to top 320' 6" ,, ground line 300' o" Outside measurement at ground line 1 7' 4" Inside ,, ,, 9' 6" Outside ,, at top 9' o" Inside 6' 8" Foundation. Concrete, 6' deep, 35' 6" diam. Tall Chimney Construction. The footings are 6' in height, built up in 4 courses of i' 6" each, and having a set off each time of i' 6". The bricks in the first course of footings numbered 1,997. Construction. From top of footings to ground line, 8' 6", the base of shaft is circular, being 19' in diam., with walls 5' thick. The flues enter the shaft in this circular base on four sides, and are each 6' 9" high x 2' 6" wide, and are lined with 9" fire brick. The shaft from the ground line is octagonal, and is built up in eight sections as follows : 1st section 2nd 3rd 4th 5th 6th 7 th 8th Batter. i in 72. 30' o" high 3' n" wide 5 bricks. 60' o" 3' 6" =4i 30' o" 3' 2" = 4 30' o" 2' 9" = 31 30' o" 2' 4" = 3 30' o" I' II" = 2^ 30' o" i' 7" = 2 60' o" I' 2" , , =li 300' o" from ground line. Cap. The cap is of stone 7' o" in depth, projecting 3' o"; above this there is a blocking course of brick 8' 3" in height of 14" work. Scaffold. The chimney was erected by internal scaffold, stages being erected as the work proceeded. The men and materials were hoisted in boxes, purposely constructed, by a crab worked by 4 men. Draught. The draught, as ascertained by Mr. Hugh U. McKie, City Surveyor, Carlisle, in Sept., 1877, was equal to a column of water i T 3 Q-" in height. This observation was taken among others to find the influence of the draught upon sewers which Messrs. Dixons had allowed the Carlisle Town Council to connect with their chimney, and it was found the sewers were "perceptibly ventilated for a radius of four hundred yards, equal to an area of 502,656 square yards, or over 103 acres." Duty. Four boilers connected to shaft. MESSRS. MITCHELL BROTHERS, MANCHESTER ROAD, BRADFORD. Architect, Mr. MARK BRAYSHAW ; Builders, Messrs. JOHN MOULSON & SONS. Description. Octagonal stone. Detailed Examples of Existing Shafts. 5 1 Dimensions, Height from foundation to top 330' ,, ground ,, 300', Flue, perpendicular throughout 7' External diameter at foundation 20' ,, ,, at top 9' Concrete Foundation, i course 22 X 22 X i' I 21 X 21 X i' MESSRS. J. CROSSLEY & SONS, DEAN CLOUGH MILLS, HALIFAX. Architect, Messrs. R. IVES & SONS, Halifax ; Builders, Messrs. PICKLES BROS. Built in 1857-8. Time occupied, 18 months. Description. Octagonal stone shaft, with circular flue. Dimensions, Height from foundation to top .......... 330' ,, ground line ............ 300' Outside measurement at foundation ......... 32' Inside ......... 9' Outside ,, at ground surface ........ 30' Inside ........ 9' Outside ,, at top ........... 15^' Inside ........... 9' Duty. To carry off the smoke from 15 boilers. Foundation. The shaft is founded on rock. Scaffold. Inside. Fire-brick Lining. There is an inner circular shaft of 14" fire-brick, with a space of 3" between it and main shaft. Weight, 8,300 tons. COSt, ; Q- I O,OOO. MESSRS. I. C. JOHNSON & Co/s CHIMNEY CEMENT WORKS, GREENHITHE. Fig. 16. Architect, I. C. JOHNSON ; Builder, Jos* BLACKBURN. Description. Circular brick. Tall Chimney Construction. Dimensions, Total height, including foundation 304' Height from ground line 297' Outside measurement, foundation 30' Outside ,, at ground line sq 25' Inside cir 17' Outside ,, at top ,, n' Inside ,. ,, ., 8' Duty. The smoke and vapour from 19 cement kilns. Fire-brick. No fire-brick lining, the chimney being 300' from kilns. Foundation. The concrete foundation is 30' sq. X 4' thick, laid on the solid block chalk. The brick footings are 3' in height. Bricks. Burham gault, No. 3 wire cut, 9" x 4|" X 2 J" full. bond is Flemish. The shaft for the height of 10' from footings is 25' square externally, with a circular internal diameter of 1 7' 6". There are constructed at the base for a height of 10' four walls or withes to prevent counter draughts. There are four openings made at base of shaft, one on each side of the square, for although only two openings were required, Mr. Johnson advisedly constructed four, so that the brickwork should be equal in strength on all sides ; the openings not wanted are built up in 9" work. In one of the openings there is a small furnace, which is only required at starting fire. The shaft is constructed in eight sections as follows : ist section ....... 10' high sq. 5 bricks thick. 2nd 3rd 4th 5* 6th 7th 8th 4i' circ. 4^ 41' 4 4i' 3s 4i' 3 41' 4i' 4i' 297' high above footings. The upper 41' being of smaller diameter than the others, the bricks did not quite fit into the circle, so the tips were cut off the stretchers ; a 9" brick suited the circumference every- where else. The shaft stands on ground about 50' above river level at high water. Detailed Examples of Existing Shafts. 53 Scaffold and Construction. This shaft was built up from inside. Battens on edge were built in every 5' or 6', and covered with boards to form a platform for men to work upon. When the top was reached these battens were cut out and dropped down, and as they were available for other purposes the cost of scaffold was comparatively trifling. The materials and men were hoisted, by a crab and good manilla rope, up the centre of the scaffold, and not a single accident happened during the whole time of building. Cap. A string course 20' from top is made of three salient courses of brick, and 5' from top four courses oversail to about 9". The top salient course of same is of stone 3" thick and was put together in segments clamped with galvanized iron clamps run with lead. Lightning Conductor. f" copper rope, fixed by Messrs. Newall & Co., as follows : One of the bricklayers was lowered outside by a rope, before the internal scaffold was struck ; he fixed gun metal eye bolts into the brickwork at intervals, pass- ing the wire rope (which had been drawn up inside) downwards through them until the whole was fixed. MERRIMACK MANUFACTURING COMPANY, LOWELL, MASS., U.S.A. Engineer, J. T. BAKER, C.E. ; Built, 1882. Description. Circular brick shaft, with inner shaft and core. Dimensions, Height above ground line 282' o" Outside diam. foundation 30' o" Outside ,, 2' 6" above ground 28' o" Inside ,, ,, 12' o" Inside at top 12' o" Foundation. The chimney is founded on a ledge of sand- stone. The foundation, 30' in diam., is built of granite blocks, laid on their natural beds. At the surface of the ground there 54 Tall Chimney Construction. is a dressed granite base 2' 6" in height, laid in clear Portland cement, the remainder of the foundation being in Rosendale cement and sand. Upon this base is placed the brickwork, consisting of three cylinders, as follows: Outer Shaft. Batter, -42" per ft. for a height of 100'. ist section .... 75^' high, 28' diam. 24" thick. At junction of inner shaft, 36!" 2nd .... Co' high .... 20" 3rd .... 70' .... 16" 4th .... 74' including cap 1 2" 279^' high above granite base. Inner Shaft. Vertical, 1 8' diameter; 75 J' high; 8" thick. At this height the inner shaft connects with the exterior brickwork, making the masonry at that point 36^" thick, as above. Lining or Core. Uniform inside diameter, 12'. It is entirely separate from the outside masonry, except the doorways and flue openings, and is built up as follows: ist section 100' high 16" thick. 2nd 60' 12" 3^ 90' 8" 4th 29!' 4" 279^' high above granite base. Constrtiction. The core was laid in mortar of lime and sand ; the outside shell in lime, cement and sand. Ladder and Lightning Condiictor. On one side of the chimney is a ladder of iron extending from the ground to the top, and on the opposite side is a J" galvanised iron wire rope, both ladder and rope being connected with a copper ring, having four spurs, the central point of which extends 8' above the top of the shaft. The bottoms of both ladder and rope are connected to a 1 6" water pipe. Duty. Two wrought-iron flues enter the chimney, one 5' x 6', and the other 5' x 1 1'. The chimney is constructed to provide for 15 sets of boilers; only 12 are now in use. Each set has 103^ square ft. of grate surface, and is rated at 300 h.p. Weight. Chimney, 3,392 tons; cap, i8,6oo-lbs. Materials. i , i o i ,000 bricks ; 6,875 cubic feet stone masonry. Cost. 18,500 dollars, or 3,854. 35. 4d. Detailed Examples of Existing Shafts. 55 )6' o" 2' o" 2' o" thi ck. 6' o" 3' 2' 2' 3" 5" I' 6" I* 6" 0' 9" MESSRS. Cox BROTHERS, CAMPERDOWN LINEN WORKS, LOCHEE, DUNDEE. Fig. 17. Architect Mr. JAS. MACLAREN. Description. Ornamental brick, square to a height of 230'. A balcony or cornice is here constructed. From this to top the chimney is octagonal. Dimensions, Height from foundation to top 296' ,, ground line 282' Foundations 35' o" square, walls At ground line 30' o" At top of ist panel 24' o" main 21' 3" balcony 20' 3" ,, chimney 19' o" Circular flue at base 14' 6" internal diam. top 13' 8" Construction. The chimney is panelled and ornamented by designs in parti-coloured bricks. The base is of ashlar, and surmounted by massive stone mouldings. Above this is the first panel, the pilasters of which are checkered red and white. Above this is a base moulding*, out of which spring the sides of the next or main panel, which extends to a height of 185' 2" above the ground. It is relieved in the centre by loop holes and sham clock holes at the top, and the sides of the main panels are striped red and white. The tops of the main panels are arched, and above them are two smaller panels, on each face of the chimney, surmounted by a Grecian frieze and other ornaments in white and black bricks. Over this is constructed the cornice or balcony, round which there is an ornamental iron railing. Ladder to Balcony. The outside walls being square, while the inner shaft is circular, a space is left at each corner, and access to the balcony has been obtained by utilizing one of these spaces in which to construct an iron ladder. Flues. The flues are of elliptical form, 9' 6" x 5' 6", and constructed in each of the four sides, but at present only two are in use. Duty. There are 58 furnaces connected to the chimney, and also 13 smith's forges, and in addition the draught is used for other purposes. Draught. The draught is now equal to a water pressure 56 Tall Chimney Construction. WROUGHT IRON CHIMNEYS. Wrought iron shafts have found great favour in America and Russia, but in England and the Continent generally, as far as we have been able to ascertain, they are an exception. In addition to the wrought iron shafts, detailed descriptions of which will be found in order of their respective heights (see Index), we have been informed of the following : Messrs. Witherow & Gordon, of Pittsburg, Pennsylvania, U.S.A., have, since 1876, built upwards of 30 wrought iron shafts, varying in height from 100' to 190', and from 5' to 9' in diameter. The firm write us that these shafts answer admirably the purpose for which they were built. Mr. L. S. Bent, Superintendent of the Pennsylvania Steel Company, Steelton, Pa., U.S.A., states that his Company have the following eight wrought iron shafts in use, and have found them both durable and economical: No. i . . . 170' high 6' 6" diam., built 1881 i ... 165' 6' 6" 1877 i ... 135' 7' o" 1880 i ... 112' 6' o" 1881 4 . . . 1 10' 7' o" 1869-74-5-6 They are lined for 30' with 9" fire-brick, and the remainder of height with 4" red bricks. M. M. SCHNEIDER & Co., CREUSOT. At the above works, in 1869, the chimneys that had served for nine years to carry away the products of combustion from 24 boilers became inadequate to meet the increased requirements of the establishment, which had been considerably extended from time to time ; and it was decided to construct a new chimney in connection with an additional group of boilers. This new shaft it was determined to build in iron. A W.I. shaft had already been erected at the works 197' in height, 4' 3" in diam. at top, and 10' diam. at bottom, with plates from -/^ at top to n--" at base in thickness, and weighing 28 tons, and had been constructed on the ground, and successfully raised in bulk to its assigned position. This formed a guide to the planning and construction of the proposed new and much larger shaft, the details of which are as follows: Constructors, M. M. SCHNEIDER & CIE ; Engineer, M. GEAY. Detailed Examples of Existing Shafts. 57 Dimensions, Height of masonry foundation above ground I M =. .... 3' 3f " Height of iron shaft from top of masonry foundation 84-35 M 276' 8" Total height from ground line 280' o" Outside diam. of masonry I M, above ground line 7 M =. . . . 22' nj" ,, ,, shaft at top 2-30 M 7' 6J" Construction. The base of shaft is in form a frustrum of a cone to a height of 10 m., or 32' 8", and is built up of eight rings of plates each 1-25 m. = 4' \" high, measuring from C to C of rivets. The base is fixed to the masonry foundation by a very strong L iron ring riveted to chimney plates, and secured to foundation by holding-down bolts. At the gth ring, from bottom of shaft, the circumference is made up of eight plates 14 mill. = -55 104" in thickness, and at the upper part the rings are each composed of four plates only, 7 mill. -27552" in thickness. Scaffold. This shaft was erected by means of a "flying scaffold," that is cross-arms or bearers resting on angle irons, riveted to the inside of the wrought iron plates as erected. These bearers carried an internal platform, and an iron tube with cross-head timbers at top, from which was suspended an outside platform, so that the men could work both inside and outside the shaft. The scaffold was raised each time a complete ring of plates had been riveted up. This was done by two beams being placed across the top of the completed ring of plates, each beam being provided with two large nuts, through which screw rods worked. Near the bottoms of the four screw rods ratchet wheels were fixed, and the four ratchet wheels were worked simultaneously, until the whole scaffold had been raised the required height, and the cross arms or bearers brought up to the level of the next set of internal angle irons, to which the scaffold was secured. The next ring of plates was then com- menced. Ladder. The internal Z. irons used in erection remained in the shaft, and would serve for future ascension. Fire-brick Lining. An inner lining of fire-bricks was constructed for a height of eight plates, or 32' 8". Weight. Masonry in foundation, about 300 tons ; weight of iron shaft, 80 tons. Cost. This shaft, exclusive of foundation, cost 1, 600. E 58 Tall Chimney Construction. BARROW HEMATITE IRON AND STEEL WORKS, BARROW IN-FURNESS. Architect, A. WORRALL; Builder, A. J. WOODHOUSE. Built, 1865 May to Sept. inc. 5 months. Description. Circular brick. Dimensions, Total height, including foundation 282' o" Height from ground line to top 259' o" Outside measurement at foundation 41' 8" Inside at base of shaft 16' 8" at ground line 31' o" Outside Inside Outside Inside 1 6' at top .......... 16' 6" 15' Foundation Bed. Stiff clay. Fire-brick Lining. The shaft is lined throughout with 4j fire-brick, bonded to main shaft every third course. Scaffold. Inside. Brickwork. Purposely-made bricks were used in the con struction laid to Old English bond, without hoop iron. Lightning Conductor. Copper stranded rope. AMOSKEAG MANUFACTURING COMPANY, MANCHESTER, NEW HAMPSHIRE, U.S.A. Architect, GEO. W. STEVENS ; Steam Engineer, CHAS. H. MANNING. Builders, AMOSKEAG MANUFACTURING COMPANY. Description. Circular brick; built 1883; 60 days occupied in construction. Dimensions, Total height, including foundations 265' o" Height from ground line to top 255' o" Outside measurement at foundation 25' 8" Inside ,, ,, 19' 8" Outside diam. at ground surface 25' o" Inside ,, ,, 19' 8" Thickness of brickwork ,, 2' 8" Outside diam. at top (exclusive of cornice) 12' 6" Inside ,, 10' o" Thickness of brickwork at top i' 3" Detailed Examples of Existing Shafts. 59 Foundation. The shaft is founded on a bed of ledge. No concrete used. Pressure. On foundation (as given by the firm) is io,22o-lbs. per square foot. Bond. Headers every tenth course. Batter. i in 40*8. Bricks. 1,000,000 common bricks used in construction. Weight. 2,330 tons. Scaffold. Outside scaffold used, costing 750 dollars = Duty. This shaft was designed to burn 1 8,ooo-lbs. of anthracite coal per hour. It carries off the fumes from sixty- four boilers = 8,400 h.p. The company chiefly manufacture ginghams, tickings and fancy shirtings. Inner Shaft. The chimney has an inner shaft of 10' internal diameter. Lightning Conductor. Wrought iron ; costing 95 dollars = 19. 155. lod. Cost. Complete, 16,000 dollars =,3,333. 6s. 8d. MESSRS. LISTER & Co., MANNINGHAM MILLS, BRADFORD. Fig. 1 8 (the tallest chimney in Bradford). Architects, Messrs. ANDREWS & PEPPER ; Clerk of Works, A. RHODES. Builders, Messrs. J. & W. BEANLAND. Description. Square ornamental stone chimney, of uniform width from base to top, with panelled sides. Dimensions, Height from ground line to top 256' 6" Outside measurement base and top 21' o" Inside ,, at base 10' o" ,, ,, under cap n' o" ,, at top 13' o" Fire-brick Lining. An inner shaft of fire-brick is constructed for a height of 50' in 9" work, leaving a cavity between it and the shaft proper of 4". 60 Tall Chimney Construction. Foundation. The foundation bed is clay; upon this is a layer of Lias lime concrete, 4' thick x 40' square, then two courses of large rag footings or landings, each course 12" thick, well bedded and bonded. Some of the landings were 12' x 7' X i' in size. The quantity of stone used in the footings was about 3,300 cubic feet. Lime. Barrow Lias lime used throughout. Materials. Total weight, about 8,000 tons. Scaffold. Inside. Cost. 10,000 about. WEST CUMBERLAND HEMATITE IRON WORKS CHIMNEY. Figs. 19 and 20. Engineer Prof. W. J. M. RANKINE. Description. Circular brick, Old English bond. Dimensions, Total height, including foundation 267' o" Height from ground line to top 250' o" Foundation bed of concrete 3' deep X 34' 6" sq. Outside measurement at bottom of footings 31' 6" of sq. basement 30' o" of bottom of circular shaft ... 25' 7" Inside diam. Outside of circular shaft 2' above oct. base. 21' 10" top of shaft 13' o" 15' 3" Contract and Execution. Tenders were invited from a limited number of builders in the north of England and in Scotland, and the lowest was accepted, being that from Messrs. William Wilson & Son, of Glasgow. The progress of the building was restricted by the specifi- cation to a rate not exceeding 6' vertical height per day. Concrete Foundation. In order that the concrete foundation might have time to harden, before being subjected to a heavy load, it was made by the Iron Company themselves before the contract for the chimney was let. Building. By dimensions given above and reference to diagrams 19 and 20, it will be seen the concrete foundation is Detailed Examples of Existing Shafts. 6 1 square. Upon this bed four courses of footing are built, then a basement 30' square, which is gathered into an octagon by gradually stepping the brickwork at the corners ; from this line to the top the shaft is circular. There are four circular openings, 7' 6" diameter, with archings three bricks thick in the base for flues. The batter of circular shaft is uniform throughout, and was adopted because the accuracy of building can be tested at any moment by the eye without the aid of instruments. Thickness of Brickwork, ist section at top 80' o" =. i|- bricks, including fire-brick lining. 2nd 80' o"=z2 3rd 88' o" 2j 2' o" = stepped from 2\ to 4 bricks. Total, 250' o" from ground line. Scaffolding. Internal scaffolding was used, and in its con- struction great care was taken that the horizontal beams should be wholly supported by the brickwork, and not by the vertical posts, for great danger has been known to arise from the upper brickwork coming to bear upon the ends of the horizontal timbers, and through them on to the vertical posts, owing to the settlement of the lower part of the chimney. (See description of Port Dundas Chimney " Straightening/') Stability. Prof. Rankine gives the bed joint of least stability at 2' above the ground line, and the deviation of the resultant pressure from the axis of the chimney at that joint, which would be produced by such a wind as 55-lbs. per square foot is 6' 4", being a fraction of an inch less than \ of the outside diameter. Pressures. The following are the intensities of the mean pressures due to the load on different bed joints : At 2' above the ground line 8 tons on the sq. ft. In basement at springing of the arches . . 3 ,, ,, ,, On upper surface of concrete 2 ,, On ground below ,, i'6,, ,, ,, Fire-brick Lining. This is included in the thickness of brickwork, as before stated : Upper 1 60' o" of the shaft \ brick thick. Lower part of the cone, basement, flues, and archways . . I ,, The fire-brick lining is bonded with the common brickwork in the ordinary way, the only difference being that the fire bricks are laid in fire-clay and the ordinary bricks in mortar. The reasons given for adopting this mode of construction, by 62 Tall Chimney Construction. Prof. Rankine, in preference to an internal fire-brick chimney, are as follows : 1st. When the fire-bricks are bonded with the ordinary bricks they contribute together to the stability of the chimney, and so save an additional thickness of ordinary brickwork. 2nd. Unless the internal chimney is carried up to the top of outer cone there is a risk of damage through the explosion of gaseous mixtures in the space between. 3rd. There is also a risk of the cracking of the outer cone at and near the upper end of the inner cone, through unequal heating at that place, unless the inner shaft is carried to the top of the outer one. The basement is paved inside with 6" of fire-brick, resting on 6" of common brick laid on the concrete. Ordinary Brickwork. The ordinary brickwork is built of white bricks of good quality supplied by the Iron Company. The bond is Old English. In the basement there is one course of headers to every two courses of stretchers. In the cone one course of headers to every three courses of stretchers. Hoop Iron. Strips of No. 15 B.W.G. hoop iron, tarred and sanded, are laid in the bed joints of the cone, at intervals of 4' in height, with their ends turned down into the side joints. Care was taken to bed the hoop iron on the common brickwork, and not on the fire-brick lining. The length of hoop iron, in each bed joint in which it is laid, is twice the circumference of the chimney at that point. Mortar. In the concrete foundation, the basement and a small part of the cone, the mortar was made of hydraulic lime. Owing to an unexpected difficulty in obtaining such lime on the spot, it had to be brought from a distance, at considerable expense, and, therefore, the mortar for the rest of the building was made of a very pure lime from the immediate neighbourhood, rendered artificially hydraulic by a mixture of iron scale from the rolling mills at the works. The following are the proportions by measure : Lime . 2 Scale i Sand 5 Total The use of iron scale for hardening mortar and making it artificially hydraulic should be more generally known. Cast Iron Curb. On the top of the chimney is a cast iron curb, i" thick, coming down 3" both inside and outside. It was "paid" over with a coating of pitch when fixed. Lightning Conductor. The lightning conductor is of copper wire rope, about f " diam. It terminates in a covered drain. Detailed Examples of Existing Shafts. 63 Cost. Actual cost, including designing and superintendence, was ,1,560, being at the rate of almost 4d. (fourpence) per cubic foot of the whole space occupied by the building, which is 94,000 cubic feet nearly. Duty. This chimney has to carry off the gaseous products of combustion from four blast furnaces, and from various stoves and boilers that are heated partly by burning the inflammable gas from the blast furnaces and partly by coal. The total quantity of solid fuel consumed is about ioj tons per hour, when all the furnaces are at work. Temperature and Draught. The temperature inside the chimney, when doing about three-quarters its full duty is 490 Fah., and the pressure of the draught is i J" of water, which agrees to a very small fraction with the pressure as deducted theoretically from the temperature and the height of the chimney. LANCASTER: MESSRS. STOREY BROTHERS & Co., WHITE CROSS STREET MILLS. Fig. 21. Engineer, Mr. EDWARD STOREY ; Architects, Messrs. PALEY & AUSTIN. Contractor, Mr. C. BAYNES. Btdlt 1876-7-8; about 18 months being occupied in its construction. Description of Shaft. Octagon brick with stone cap. Dimensions, Total height, including foundation ........ 270' o" Height from ground line to top ......... 250' o" Outside measurement at foundation ....... 28' o" Inside ,, . ....... 17' o" at ground surface ...... 25' o" Outside Inside Outside Inside 17' at top ......... 10' 8" ......... 9' 2" Materials. 750,000 brick, 650 cubic feet stone and 145 cubic yards concrete. Foundation. The shaft stands upon a base of concrete 2 8' square X 5' thick. Bricks. "Shale" bricks, supplied by the Caton Brick and Tube Company, were used. These were chosen because they are said to absorb less moisture than ordinary bricks. 64 Tall Chimney Construction. Internal Shaft. This is octagonal in form, 264' high x 8' internal diameter, built 18" thick at base and 9" at top. It is built parallel to within 12' of the top, then sets back 7" at each side, as shown in diagram 2 1 . The inner shaft carries off the smoke from the steam boilers. It is surrounded by a space or cavity 2' 6" wide, enclosed by the outer shaft, and the vapours from the stoves, &c., are passed off through this 2' 6" space. This space between the inner and outer shells is divided into three distinct flues by vertical diaphragms of brickwork, which latter serve to tie the whole structure together. Outer Shaft. The brickwork of outer shaft is 4' 6 ' thick, where it rests on the base, and 14" thick at top. About 20' from top of chimney the outside wall curves inwards, and joins the inside wall as shown on drawing. Annular Flue or Cavity. It will be seen at the junction of the inner and outer shafts two outlets are constructed in each of the eight sides, so as to allow the heated air, vapours, &c., to escape from the annular flue, the principal of which is more fully described under the head of Print Works Chimney, Falls River, U.S.A. Weight. Total, 3,300 tons. Cost. ^2, 800 complete. Deflection and Straightening. During the erection of this chimney, when it had attained a considerable elevation, it canted out of the perpendicular towards the south 3' loj" at top. This was accounted for partly because during the two years occupied in its erection very frequent rains kept the mortar soft on the weather side, the result being that the joints on that side were squeezed rather closer than those on the other, and the stalk heaved or bent over. The principal reason, however, must have been that the foundation was a little weak on the south side, and thus yielded to the pressure, the weight on that side being increased by the deflection of the chimney. The work of bringing it back plumb was successfully executed by Mr. J. W. Cronshaw, of Blackburn. The operation consisted in cutting out courses of bricks in 5 different places near the base on the north side of the chimney, and rather more than half way across. These courses were replaced by ones diminishing very slightly in thickness from south to north, so that the five courses shortened the north side of the chimney sufficiently to bring the axis in a true vertical position. The process of cutting was as follows : A width of about 1 8" was first cut right through the 4' 6" brickwork of the outer shell on the extreme north side, a course Detailed Examples of Existing Shafts. 65 of bricks being 1 then withdrawn, and the top and bottom joints being thoroughly cleaned off. Into this space 18" wide, good hard bricks were then closely packed, these bricks being thinner, as already explained, than those they replaced. At the outer end good oak wedges were inserted ; then similar cuts were made right and left of the first, and similarly treated with bricks and wedges, the work proceeding regularly on each side, east and west, from the north towards the south. As this was done the wedges were gradually withdrawn, and the chimney quietly settled over towards the north, until when all the five cuts were completed it had come back to the perpendicular. The lowest cut was close to the ground, and the highest about 30' above. Two of the cuts were continued into the internal shaft. CONNAH'S QUAY CHEMICAL COMPANY'S CHIMNEY. Description. Square brick shaft. Dimensions, Total height from foundation to top 258' 6" Height from ground line to top 245' o" Outside measurement at foundation 28' 3" Inside ,, at ground surface 17' 6" at top 7' o" Weight and Materials. The weight of stone in this erection was 645 tons, in addition to which 1,078,000 bricks were used. Cost. ^2,000. This price will doubtless be considered very low, but the Connah's Quay Chemical Company, for whom this stalk was erected, say that the cost was but little over the above sum. NEWLAND'S MILL CHIMNEY, BRADFORD. Figs. 22 to 30 inclusive. Built for the late Sir H. W. Ripley, Bart., 1862-3, b y Messrs. JOHN MOULSON & SONS. Description. Octagonal stone shaft. 66 Tall Chimney Construction. Dimensions, Total height from top of concrete shafts 260' o" Height from ground line 240' o" Concrete foundation, sq 32' 6" Outside measurement on stone footings 24' o" Inside diam 12' 2" Outside measurement at ground line 24' o" Inside diam. ,, 12' 2" Outside measurement under cap at top 14' o" Inside diam. ,, ,, 9' o'' Fire-brick Lining. 9" thick. Height from top of footings 30' o" Insi4e diam. throughout 9' o" Withe, height from footings 10' o" *& 25. Foundation. The site was an old coal shaft, which was filled up with Skipton lime concrete, forming a centre pillar 8' 6" diameter. Round this were constructed four other shafts, each 6' diameter, also of concrete, the sinking of which cost 95. 6d. per yard per shaft. Upon this formation was laid a tabling of lime concrete 32' 6" square x 2' 6" thick, the base courses or footings of the chimney resting upon it. The concrete was not rammed, but was tipped in from staging ; it was almost liquid and nearly levelled itself by the drop. The old workings surrounding the centre shaft were packed with stones and oak wedges. The amount of contract for sinking the four shafts, packing coal beds, cleansing and searching old workings, and ascertain- ing condition of ground, \vaS;io4. iys. gd. Figs. 24, 29, 30. Materials. Outer stone casing, stone backing, and 9" common brick lining throughout, fire-brick at bottom. Weight. Total, 3,600 tons ; above cuts (made in straight- ening described further on), 2,230 tons. Pressure, 4*5 tons per foot sup. of foundation. 22-4 ,, ,, on 5 concrete piers. Contract. The construction of the chimney was settled as follows: The late Sir H. W. Ripley, Bart., being desirous of erecting a chimney, sent for Messrs. J. Moulson & Sons in May, 1862, to give a tender. There were no plans or specifications prepared when the tender was given, but the following formed the basis of the estimate: Chimney to be 8o-yds. high, 9" flue, base 24' square, with two courses of footings 12" thick, the first 28' Detailed Examples of Existing Shafts. 67 square, the second 24' square, placed on a good bed of concrete. The builders undertook to execute the workfor^942. 55. lod. The Ashlar foundations, concrete and capping, to be extra. Building. At the ground line the chimney was a regular octagon, and was so continued upwards at a regular batter of !" to the yard. The chimney was commenced July, 1862, and continued to the middle of December (the back end of the year being open), the building was then suspended, being a little more than 120' high. The work re- commenced 28th February, 1863. "Through" stones were built in at about every 3' in circumference, and about 2' 3" apart vertically. The erection was continued to the yth June, the chimney having reached 210' in height. Figs. 29 and 30. Straightening. On the evening of this day (yth June), the chimney was left plumb. On the 8th it was found to be bulged on one side, and hollow on the other. About 5 4' from ground line a course of stones was cut out on the opposite side to the canting over. Two men outside with long chisels cut away, say for i' wide on the outside, a 7" stone course and through the backing ; two men from the inside cut through the brick lining, and met the opening cut through the backing from the outside. This space was filled up with stones J" less in thickness ; upon these were placed long feather-edged iron wedges to make up the original thickness. This operation was continued nearly- half-way round, with the exception of the angles which were left. Before proceeding to draw the wedges, mastic cement was introduced by means of syringes. The wedges were then withdrawn by hammering them sideways, both from inside and outside. As the wedges were removed the men could hear the "through" stones breaking. The first cut did not have the desired effect, and a second was decided upon about 2' above the first, with the same results as to breaking the " throughs." The chimney was, after this, declared to be perpendicular. In the " coming to," the corner stones at the angles were crushed for about 1 2' above and below the cuttings. These were replaced, and the chimney was then completed. Cracks. Three years after completion the chimney was found to be cracked and broken on the side opposite to the cuts. This was repaired at a cost of ^96. About 1872 further cracks were noticed, which were repaired. In October, 1882, the tenants of the mill became uneasy about further indications of cracking, which, in December, developed into bulges. Upon examination it was decided to take out the bulges and repair the outer casing, it being th 68 Tall Chimney Construction. general opinion the latter was alone at fault. Difficulty was experienced in this, and the attempt to rectify the bulge failed. Collapse. On the 26th Dec. small portions of the outer casing fell, and on the 2yth a large piece fell, breaking down the scaffold used for the repairs. On the night of the 2yth the wind blew half a gale, or about i6-lbs. per foot super. On the following morning, 28th Dec., more of the outer casing fell, and at a few minutes past eight a.m. the chimney began to settle, bursting out stones and lime near where the chimney had been cut. This continued for a few seconds, then the upper portion of the chimney fell in a S.E. direction, killing 54 persons, and destroying property estimated at ^20,000. In 1884 a test action was brought against Messrs. Ripley by the sufferers through this disaster, and resulted in the whole matter being referred to an arbitration, which awarded in the aggregate ^2, 5 oo as damages. PACIFIC MILLS, LAWRENCE, MASS., U.S.A. Architect and Builder, H. F. MILLS, C.E.; Built, 1873. Description. Brick, octagonal outer shaft, circular inner shaft, vertical inner lining. Shaft situate 210' from boilers. Dimensions, Total height 242' o" Height of outer shaft, including footings 233' o" Height of inner lining 234' o" Outside measurement outer shaft at base 20' o" ,, ,, ,, ,, at top, under projecting cornice . n' 6" Inside diam. vertical flue 8' 6" Foundation. Foundation bed, 19' below ground, coarse gravel, Concrete 35' square, enclosed by pine sheet piling . . i' thick. Rubble masonry of granite in Rosendale cement ... 7' high. Outer Shaft. This is constructed in six sections, viz. : ist section 12' high 28" thick. 2nd 1 8' 3 rd 4th 5th 6th 20' 40' 60' 83' 20" 1 6" 12" 8" 233' high above granite masonry -. Detailed Examples of Existing Shafts. 69 Inner Shaft, ist section 27' high 24" thick. 2nd 154' 12" 181' Lining, ist section 20' high 20" thick. 2nd 17' 16" 3^ 52' 12" 4th 145' 8" 2 34' high above granite masonry. Construction. The foundations were laid in mortar of Rosendale cement and sand ; the outer shell in mortar of Rosendale cement, lime and sand ; and the flue walls in mortar of lime and sand. Duty. In the winter of 1873, the vertical flue having reached 90' in height above ground, boilers having 452 square feet of grate surface were connected with the chimney, with satisfactory results. The chimney was designed to serve boilers having 700 square feet of grate surface. Weight. The approximate weight of the chimney is 2,250 long tons. Bricks. There were 550,000 bricks used in the construction of this shaft. Lightning Conductor. The shaft was struck by lightning in June, 1 880, after which date a lightning rod was put up. It consists of a seamless copper tube, -^' thick, i" inside diameter, at the top of which are seven points radiating from a ball 4" in diameter, the top of the central point being 8 J' above the iron cap. The rod is attached to the chimney by brass castings, and is connected at the base to a 4" iron pipe extending 60' to a canal. DOVERCOURT CEMENT WORKS, MESSRS. JOHN PATTRICK AND SONS. Figs. 31, 32 am* 33. Designed and built by Mr. JOSEPH BLACKBURN. Built, 1883, between January and October ; 7 months occupied. Description. Brick, square base, octagonal shaft. 70 Tall Chimney Construction. Dimensions, Total height, including foundations 249' o" Height from ground line 230' o" Outside measurement at base of footings 22' 2" Inside at top ,, 9' 2" at ground line 19' 3" Outside Inside Outside Inside 8' 9 at top 9' 5" 7' o" Foundation. The foundation bed is clay ; upon this is laid a block of concrete, 26' square x 8' thick, upon which the footings commence. Fig. 31. Pedestal. The square pedestal is 37' high above concrete bed, thickness of brickwork 5' 3", octagonal flue, without fire-brick lining. The foundation and pedestal were allowed time to settle before building of shaft was commenced. Shaft. Octagonal brick, thickness at base 4' 3", thickness at top 14!". At the junction of the octagonal shaft and square pedestal pyramidal corners are constructed 12' 6" high, so as to equalise the bearing of shaft on square base. Cap. Constructed of brickwork. Materials. Concrete, six sand and gravel to one cement. Mortar, five river sand to one white chalk lime ; to each $-yd. of mortar one bag of Portland cement added (the whole well tempered before use). Bricks, kiln burnt, 9" x 4j" X 2j", with white Burnham brick angles specially made ; total, 280 m. Weight. About 1,800 tons. Bond. English. Scaffold. Inside, costing 7. IDS. Lightning Condiictor. Copper tape, 2" x -J-", terminated about 20' from base of chimney, laid in carbonaceous material, well watered and rammed. Cost ^40 fixed. Duty. This chimney serves twelve cement kilns and twenty- four coke ovens. Cost. Total, ,2,000. Detailed Examples of Existing Shafts. 7 1 WOOLWICH ARSENAL, SHELL FOUNDRY, CHIMNEY. Description. Octagonal brick shaft, square base. Dimensions, Height from foundation above concrete to top . . . . 239' 9" Height from ground line to top 223' 9" Outside measurement of square base 20' o" Height of base above ground 27' o" octagonal shaft above base 196' 9" External diam. of ,, at ,, 16' 9" ,, ,, ,, at top ,, 6' 6" Thickness, Base of octagonal shaft .... 2' 7^" Top . . . . 9" The brickwork is reduced 4^" at every 31' 6", the topmost length being 26' in height. Foundation. Concrete. Construction. The whole of the chimney is built in mortar, with the exception of the top 9', which is bell-mouthed, and built in cement. The total time occupied in the erection of this stalk was nineteen weeks. Cap. This is of Portland stone, with blocking course, and weighs about 17 tons. Scaffold. Inside. MESSRS. J. C. GOSTLING & Co., CEMENT WORKS, NORTHFLEET, NEAR GRAVESEND. &&* 34 3S> 3 6 - Architect, JAMES CUBITT ; Builder, Mr. BLAGBURN. Built June, 1873 ; 16 weeks (good weather) occupied in erection. Fell, Oct. 2nd, 1873. Description. Circular brick. Dimensions, Height, including foundation 227' 3" ,, above ground 220' o" Outside measurement base of square footings .... 30' o" ,, diameter at ground line 22' o" Inside 14' 6" Outside ,, at top u' o" Inside ,, ,, 9' 6" at 4' 7^" from top 8' 9" 72 Tall Chimney Construction. Foundation Bed. Chalk. Shaft. This was constructed in nine sections, viz. : Footings 7' o" 1st section . ,26' 2nd 3rd 4th 5th 6th 7 th 8th 9th Batter. i in 40. 26' 3" . 26' 3" . 26' 3" . 26' 3" . 26' 3" . 26' 3" - 31' io" . 4' 7i". 3' 9" thick. 3' 4l" 3' o" 2 ' 7F 2' 3" I' 10^" i' 6" i' ij" 9" 227' 3" total height. Cap. This was formed of equal over-sailing courses of brick, laid in cement -mortar (see construction), each course projecting about of an inch beyond that below. The extreme projection attained at top of cap was 15^" beyond the vertical line drawn from starting point, but as it took 9' 9" in height to do this, and as the batter was 3" in 10', the projection of the top of cap from the receding line of shaft was 1 8 J". Upon the cap there were eight flat projections or piers, constructed each i' 1 1" wide, carried up in over-sailing courses, ranging with those of the body of the cap. The projection of these piers from top to bottom was 4^" beyond the main part of cap, and the bottoms of them were supported on a series of courses over-sailing more gradually than the upper ones. Above the cap the shaft wall was continued for a height of 4' 6" in 9" work. Bond. The bond was that known as "half-brick bond," and contained at least twice as many stretchers as would occur in Old English bond. Weight. Shaft, 1,674 tons; cap, 19 tons 3 cwt. Pressure, On base of 3' 9" work . . 6| tons per ft. super. ,, i' i|" below cap . ,, ,, Construction. Messrs. J. C. Gostling & Co. made arrange- ments with Mr. Blagburn to provide labour for the erection of the shaft as above detailed for ^500, the firm providing all materials. The best Dorking grey stone lime was used with the best Thames sand, every few courses being grouted in with Portland cement. The whole of the upper part of chimney was built of the best picked paviors, all imperfect bricks being rejected. The lower part of the walls was partly composed of the hardest stocks that could be obtained and partly of paviors ; and within 50' of the ground there was a small proportion 5% Detailed Examples of Existing Shafts. 73 of rather over-burnt and somewhat vitrified bricks, approaching in character to "rough stocks." There was no difference between the facing and backing, the same quality of bricks being used for the entire thickness of wall. At intervals of about 3' two successive courses of brickwork were built with the vertical joints dry, and then grouted with neat Portland cement. The cement, which was thus poured in as grout, set admirably. After falling 200' these bricks were still found joined in double courses, and they had as often broken through their own substance as through the cement. There was not the least sign of expansion caused by the cement, and a large mill floor at the works was laid at the same time with the same lot of cement, and no flaw or blister subsequently appeared. The cement used was the best of the Burnham Cement Company's make. The original intention was to mix the cement with an equal measure of sand for the construction of the cap, but by the advice of persons experienced in this class of building it was used with a small quantity of mortar. The idea was, that though the ultimate strength of the cement and sand might be as great, yet the cement and mortar would adhere to the bricks better at the beginning. Whatever may have been the cause it appeared after the accident that a considerable part of this cement-mortar had not set with anything like the firmness of the neat cement grouting. Collapse. On Thursday afternoon, Oct. 2nd, 1873, the shaft being virtually finished, Messrs. Gostling attended to witness the laying of the last brick. At about one o'clock, when the workmen were about to ascend, one man having actually reached the top, the upper part of the shaft was observed to bulge outwardly, and immediately afterwards about 60' of the top fell, both outside and inside the chimney, resulting in the death of six and injury of eight men. The outline of the fractured shaft was highest on the south- west side, and sloped irregularly in the opposite direction, as see dotted line, Fig. 34. The top of the ruin overhung consider- ably towards the north-east, and there were vertical fissures extending for a short distance down. The smaller fissures, and very likely some of the larger ones, were produced as follows : The cross timbers, on which one after another the internal scaffolds had rested, were left in till the completion ; at the moment of the accident great masses of brickwork fell on these timbers, and thus violently jarred the walls at the points where they were inserted, and the result was that many of these points were subsequently traceable on the outside by bulges and radia- ting cracks. The only witness who deposed at the inquest that he saw the actual collapse from the outside stated that it began by F 74 Tall Chimney Construction. bulging at a point on the north-east side of the shaft some 10' below the cap. The remains of the chimney were blown down by the Royal Engineers on the Saturday afternoon following the accident. A charge of 5-lb. of gun cotton was first fired in the centre of the debris, in the inside of the chimney, to ascertain the effect produced on the loose masses at the top by the concussion. The cracks were opened and a few bricks brought down by it. A charge of 8-lb. of gun cotton was then placed in the centre of the chimney, about 20' from the ground, by securing the charge to the end of a pole which was put through an opening in the side of the chimney from a high bank close to which the chimney had been built. No immediate result followed, but a few moments after the charge had been fired two large masses of brickwork fell from the top, and the cracks in the chimney opened very much and extended downwards. After waiting half-an-hour to avoid risk another similar charge was fired in the same position, when the top of the ruin fell, and the base crumbled to about 30' from the ground. The remaining brick- work could now have been safely pulled down in the ordinary way, but to assist, four charges of ij-lbs. each were placed in the cracks in the chimney and fired. The result, however, was only to open the cracks further, without bringing down any quantity of brickwork. The charges were fired by Professor Abel's detonators and Siemen's dynamo-electric machine. Re-built. The chimney was re-built in 1874, 220' high, according to the original design. The special precautions which the accident in the previous year had shown to be indis- pensable were taken to ensure that all the bricks were wetted before being laid, and that none of the mortar or cement was worked up again after being spoilt or " killed." Mr. J. Cubitt acted as architect, Mr. Blagburn as contractor, and Messrs. Gostling as before supplied their own materials. NEW YORK STEAM HEATING COMPANY, GREENWICH STREET BOILER HOUSE, U.S.A. Engineer, Dr. CHARLES E. EMERY, M. Am, Soc. C.E. Dimensions^ Height above foundation 221' o" high water 220' o" ,, basement floor 217' o" * ,, ,, grates of lower tier of boilers 201' o" upper ..... 141' o" Inside measurement 27' 10" X 8/ 4" Detailed Examples of Existing Shafts. 75 Foundation. The beach of the Hudson River was, at some time, at this locality, and the foundation of the chimney was placed in fine clear beach sand, with some pockets of coarser sand and a little stone. The foundation is i' below high water. Construction. It was necessary to place within a limited area a very large boiler capacity, viz., 16,000 h.p. This was done by making four stories of boilers ; the chimney was, therefore, necessarily located with reference to these boilers, and the plan of the chimney was determined by the shape of the lot. The thickness of the walls on the interior of the build- ing runs from 5' to 20", and on the other sides from 3' to 20". Fuel, &c. About 1,000 tons of coal will be burnt daily. It is expected that elevator arrangements will be perfected to receive this amount of coal each night. More trouble is experienced with the ashes than with the coal. Clearing is done every six hours. A new bar is used that turns on hinges and gives good results. Mr. Emery says : " We have not made many experiments with coal dust ; we have to use a fuel which has some reserve power to provide for possible contin- gencies. We find coal is worth about what is charged for it." MESSRS. MARK OLDROYD & SON'S CHIMNEY SHAFT, KNOWN AS "BiG BEN," DEWSBURY. Architects Messrs. JOHN KIRK & SONS. Description. Round brick shaft without pedestal, built 1869. Dimensions, Total height, including foundation 229' o" Height from ground line to top 210' o" Outside measurement concrete bed 40' o" ,, , brick foundation 34' o" ,, , at ground surface 23' 8" Inside , ,, 10' o" Outside , at top 12' 6" Inside , 10' o" Foundation Bed. Gravel. Batter. i in 37. Bricks. 600 m. used in construction. Weight. 2,000 tons. 76 Tall Chimney Construction. Scaffold. Inside. Cap. Built of stone. Lightning Conductor. Stranded copper rope. Duty. No. 8, 40 h.p. boilers connected to shaft. Cost. ;l,200. COLTNESS IRON WORKS, LANARKSHIRE. Dimensions, Height above ground 210' o" Outside measurement at base 18' 6" at top 10' 6" Construction. This chimney is built up in five sections, as follows : 1st section 35' high 4^ bricks thick. 2nd 40' 4 3rd 50' 3 4th 40' 2\ 5th 45' i| 210' high above ground. Fire-brick Lining. 25' high, 10" thick. CLEVELAND ROLLING MILL Co., CLEVELAND, OHIO, U.S.A. Figs. 37 and 38. Engineers and Constructors, Messrs. WITHEROW & GORDON, Pittsburg, Pa., U.S.A. Built Sept., 1 88 1. About 50 days were occupied in its erection, apart from the building of the foundation proper. Description. Wrought iron chimney, bell-shaped base. Dimensions, Height, including foundations 213' 6" from ground line to top 190' o" of bell-shaped base 21' o" Outside measurement at foundation 30' 6" ,, diameter at foot of bell base 21' 2" at top 13' 6" 12' o" Internal diameter throughout , , . . H' o" Detailed Examples of Existing Shafts. 77 Foundation. Stone laid in cement, and is situate in what is termed the " Bottom " next to Cuyahoga River, where the ground is all of alluvial formation. For such a load as this chimney the foundation required close piling ; piles were driven 23' to 24' in depth, and almost in contact with each other. Through the stone foundation, No. 8, 2j" bolts were passed, connecting a circular cast-iron foundation plate of T section, 1 8" x 8J" at bottom of stonework to a similar casting upon the top of stone foundation. This top circular ring or base plate is formed with a projecting flange placed at an angle of 60 to receive plates forming bell-shaped base, 2' above ground. Construction. The chimney was constructed by inside scaffolding and built up one plate high at a time. The workmen hanging what is called a " cage " on the plates to serve as a stand for the " holder on " while riveting the plates in situ. Bell-shaped Base. The plates forming the base are bolted to the flange of chimney base ring by }" bolts, and when com- pleted to a height of 21' form a bell-shaped base 21' 2" diameter at bottom and 13' 6" at top. Shaft. From the top of bell-shaped base the wrought-iron outer casing is continued to a height of 2 1' from below top; from this point the cap is formed as shown on drawing. Rivets and Riveting. The plates are all riveted together with a lap of 2". The constructors used conical-shaped rivet heads, and the diameter of rivets for this class of work is as near as possible twice the thickness or upwards of plate, and the pitch of rivets is 5 diameters. Ladder. A wrought-iron ladder is fixed to the outside. Fire-brick Lining. A fire-brick lining was built up through the entire height of the chimney, commencing at junction of flues in foundation with a thickness of 1 8", and finishing at top 5" thick. The internal diameter, when finished with lining, is u' and constant throughout its height. The radiated fire-bricks were of five sizes, purposely made. Stability. The chimneys built on this plan are calculated to withstand 5O-lb. wind pressure per square foot with safety. The constructors say the climate of America is dry and no doubt better for such structures than the climate of England. They believe that no one alive at the present time will see the end of a W. I. chimney lined with brick. The oldest ones in America show no material deterioration. 78 Tall Chimney Construction. Painting. The wrought-iron chimneys in America are painted every three or four years with oxide of iron paint, preferably anhydrous. Cost. Complete, 13,000 dollars; or ^2, 708. 6s. 8d. SAMUEL Fox & Co., STOCKBRIDGE WORKS CHIMNEY, DEEPCAR, NEAR SHEFFIELD. Builder MR. MATTHEW BREARLEY. Description. Octagonal brick shaft, erected in 1 866 : six months occupied. Dimensions, Height, including foundation 201' o" from ground line to top 186' o' Outside measurement over sides at foundation . . . . 19' 3" Inside , .... 5' 9" Outside , at ground line . . . . 14' 9" Inside , .... 5' 9" Outside , at top 8' i" Inside , 5' 9" Foundation. Ashlar stone and brick. Inner Shaft. A fire-brick lining is provided for 90' high in 9" work, with a 3" cavity between lining and shaft proper. Bricks. 250 m. used. Weight. Total, 1,000 tons. Scaffold. Cost about ^20. Batter. f" to i yard, or i in 48. Lightning Conductor. Copper wire. BURY CORPORATION CHIMNEY. Engineer, J. CARTWRIGHT, Borough Surveyor ; Builder, CAMMICK DENNIS, Bury. Description. Circular brick. Detailed Examples of Existing Shafts. 79 Dimensions, Height, including foundations 195' 9" ,, from ground line 180' o" Outside diameter at ground line 17' 4" Inside 11' 4" Outside at top 8' 4" Inside ,, 6' o" Height of inner brick shaft 30' o" Inside diameter of 6' o" Foundation. The foundation bed is loamy clay, on which is laid a bed of concrete 32' square and 6' 9" high, the footings are stepped from 30' square to 1 7' 4" and have a height of 9'. Inner Shaft. An inner shaft 6' diameter is built parallel for a height of 30', the brickwork is 9" in thickness, the inner & of which is fire-brick. Between the outside of the inner shaft and the inside of the chimney proper there is an annular space of i' n" at ground line. Thicknesses. The chimney is divided into four sections, each of 45' in height and having the respective thicknesses as follows, beginning at the ground line, 2' 3", 2', 18", 14". The bottom section is stepped out externally to 3' in four set-offs, the highest being i' above ground line. Cap. The moulded cap is of fire-clay. Construction. The scaffold was an inside one. Purposely made radiating bricks were used. The shaft has a regular batter of f" to the yard, and was constructed in 1881, during the months of March to September inclusive. Lightning Conductor. Copper rod 213' long, cost of which fixed was 2 1. 6s. Cost. Complete, ^750. BRADFORD CORPORATION CHIMNEY, HAMERTON STREET. Engineer, J. H. Cox, Borough Surveyor ; Builders, Messrs. NAYLOR & SMITH, Bradford. Description. Circular brick shaft, built 1880, in connection with " Fryer's Destructor " for town refuse. 8o Tall Chimney Construction. Dimensions, Total height, including foundations 192' o" Height from ground line to top 180' o" Concrete foundation square 30' o" Outside diameter at ground surface 14' i" Inside 9' 7" Outside ,, at top 9' o" Inside 6' 8" Thicknesses. The shaft is composed of four sections, the lowest being 2' 9" in thickness and the highest i' 2". Fire-brick Lining. A fire-brick lining 8' internal diameter is built to a height of 45', apart from the shaft proper, thus leaving a cavity between. Construction. The foundation rests upon tough clay of a somewhat blue colour, known locally as " Bowling Tough/' The time occupied in building was nearly five months. Inside scaffold was used. The batter of shaft is J" to a yard, or i in 72. The proportion of diameter to height above ground is as i to 127. Weight. 480 tons. Cost. 567. CHIMNEYS AT GEORGS MARIEN IRON WORKS, NEAR OSNABRUCK. Fig- 39- 1st Chimney. Dimensions. The first chimney, erected in 1857, has a height of 180'. Clear width at the bottom of 10' 9" top 7' " Height of square basement built in sandstone 30'. Octagonal shaft of bricks, the walls of which are constructed of six different thicknesses, consisting of i J bricks at the top, and of 4 bricks at the bottom. The bricks are 10" long. 2nd and 3rd Chimneys. Two other chimneys, 102' high, have also a square basement of sandstone, and an octagonal shaft of bricks, with a clear width of 4' at the top and of 6' 3" at the bottom ; the walls of these shafts are each 20" thick at the top and 30" thick at the bottom. !+th Chimney. Built in four segments. A fourth chimney, erected in 1868, has a height of 102', a clear width of 7' at the Detailed Examples of Existing Shafts. 8 1 top and 9' at the bottom. The shaft is built in four thicknesses of i, i J, 2 and 2\ bricks, and the base is 18' in height, 3' 6" thick and built of sandstone. The shaft of this chimney is built from the base to the top in such a manner that it forms in the circumference four separate parts, which are simply brought in contact with each other. This arrangement is shown in diagram No. 39, in which the vertical joints are designated by letters a, b y c, d. This construction has been found to answer exceedingly well, and is recommended for chimneys exposed to various temperatures, as, for example, in the case of chimneys connected with coke ovens, the gases of which are either applied to the firing of boilers, or are allowed to escape directly into the chimney in the event of the boilers being laid off for cleaning or repairs. The latter arrangements have, however, here been supple- mented by the admission of cold air into the chimney together with the hot gases. 5th Shaft. This chimney was built in 1870, and is sufficient for twenty Cornish boilers, and has a height of 120' and a circular shaft of a clear diameter of 10' at the top, and 10' 10" at the bottom. The thickness of the walls decreases in seven steps from four bricks at the base to one brick (10") at the top. DENS WORKS, DUNDEE, MESSRS. BAXTER BROTHERS. Figs. 40, 41, 42 and 43. No. 3 Chimneys. Description. Square brick pedestals; square taper brick shafts with pyramidal tops. Dimensions, Chimney No. i. No. a. No. 3. Total height, including foundations 193' o" 112' 6" Height from ground line to top 174' o" 135' o" 102' 8" ,, ,, to base of pyramidal top 162' o" 126' o" 97' n" Height of square brick pedestal 34' o" 25' o" 25' n" Foundation below ground 19' o" 9' 10" Outside measurement at foundation 21' o" Inside , 9' 6" 4' 3" Outside , at ground line 16' 3" 13' 3" 8' 9" Inside , 9' 6" 7' o" 4' 3" Outside , at base of pyramidal top . 7' 6" 5' 9" 3' o" Inside , 6' o" 4' 3" i' 6" Erected 1854 1844 1864 82 Tall Chimney Construction. Boilers and Flues, No. 1 Chimney. This shaft carries away the products of combustion from No. 19 boilers, each with two furnaces, as follows : 15 boilers 63' below the base of chimney 225' from firing level to base of taper top 4 > 86 ' =248' ,, The smoke and gases are conveyed from both of these ranges of boilers by a long sloping brick flue or tunnel mostly under ground. When chimney No. i was designed it was of large area for the twelve boilers it was intended to serve, since then seven boilers have been added, making a total of nineteen. When it had only a few boilers connected with it soot collected inside to a considerable extent, and occasionally caught fire and burned out in sparks and showers of smut. As boilers were added the chimney became free from soot, and the inside surface of bricks clean. Mr. Peter Carmichael, in a paper read before the Institute of Engineers in Scotland, stated " In our practice invariably fas more boilers and furnaces have been added to a chimney the draught has been improved ; and it is obvious that if the opening in the chimney be too large compared with the whole of the openings at the dampers passing into it, the draught will be reduced." Taper Tops. It will be seen from diagrams Nos. 42 and 43, illustrating shaft No. i, that the tops are constructed in the form of a pyramid, by cross walls being built from each of the four corners; the advantage of this arrangement is given by Mr. Carmichael as follows : " The taper top is found to answer the purpose well, the smoke ascending from it very freely, especially w r hen there is a breeze of wind. At such times the ordinary top is acted on like a key when blown into to make it whistle, the blasts of wind affecting very perceptibly the draught of the furnaces. In the taper top this is not much felt as the wind can only blow into one or two of the four compartments at a time, and this still allows the other two to vent freely." In the discussion that followed Mr. Carmichaers paper the taper top, which diminishes the area at outlet, was opposed by several members, who advocated increasing the area at top. Oscillations. At Dundee on Saturday, the i3th day of Feb., 1864, there was a violent storm of wind, which was at its height between 2 and 3 p.m. The tops of shafts Nos. i and 2 were blown down without injury to the shafts. The storm being a more violent one than any that had occurred for twenty years, Mr. Carmichael was anxious to see how the chimneys stood the gale ; the movement of No. i shaft was plainly visible, and was a steady rocking motion like the swing of a pendulum. The Detailed Examples of Existing Shafts. oscillation did not appear to exceed 12", and the observations gave a feeling of security as to the stability of the chimney. The taper tops were re-built with bricks much heavier than those blown down, and were modelled so as to dovetail together, as shown in Figure 42. While the tops were off there was not much difference in the draughts, the cross-walls at top not being injured ; but there was more dark smoke than before, and after, and it did not rise so freely, but in a breeze of wind fell down the leeward side and clung more to the chimney. These chimneys are still working satisfactorily, and have withstood several severe gales. The owners consider the taper construction an advantage, and the shafts "yield like a fishing rod." Consumption of Coal. Mr. Carmichael, in his paper, laid before the Society some valuable data with respect to the coal consumed, draught and areas of chimneys, which we have tabulated as follows : No. of Boilers Area of shaft. Contract'd at outlet Area of shaft for each Boiler. Draught recorded in inches. Coals consumed per week of 60 hours, in tons. to each shaft. Bott. Top. by cross walls to Bott. Top. Each Total sq. ft. sq. ft. sq. ft. sq. ft. ft. Highest Aver. Lowest. Boiler. Boilers. I 19 90-25 36 25 475 I.3I 88 8 55 II 210 2 7 49 18-06 1378 7 I- 9 6 875 75 6 II 75 3 i 1 8-06 2-25 1-75 18-06 175 537 *5 '45 10 10 For twelve months he had the coals and water supplied to two ranges of boilers, one of four and the other of seven in a range, recorded weekly, with the following results : Range of Four Boilers. Two flues to each boiler, area of opening at fire bridge 123 square inches coals consumed 45 tons per week of 60 hours, or 15-cwt. per hour. \ I2 3 X 8 984 square inches total opening -- by coals per hour z_z 65 square inches for i-cwt. per hour. Range of Seven Boilers, Two flues to each boiler, area of opening at fire bridge 123 square inches coals consumed 75 tons per week of 60 hours, or 25-cwt. per hour. .*. 123 X H = 1722 square inches total opening -f- by coals per hour =. IZ^ 2 . rr 68 square inches for i-cwt. per hour. Each boiler had two furnaces, each furnace was 2' 9" wide, and had two lengths of bars each 3!' long, and consumed 1 1 tons in 60 hours. ." 2 75 X 3'5 X 2 I 9' 2 5 square feet rr fire grate area of one furnace /. 38*5 square feet ,, ,, to one boiler. /. iitons,or2 4 ,64o-lbs. = Wb f h 60 hours X 38-5 84 Tall Chimney Construction. The 123 square inches area of opening at fire bridge was adopted, after careful experiments. Mr. Carmichael stated in his paper he was of opinion that the narrow throat produces a higher temperature in the furnace, and the gases are more perfectly mixed and consumed while passing through the narrow opening, and said that at such a high temperature there was no discharge of small unconsumed cinders from the chimney. Temperature. The temperature of escaping gases is obtained by using small strips of the following metals : Zinc, which melts at 736 Fall. Lead, 612 Bismuth,, 495 Tin, 442 Small bits of each of these, about i" long x J" broad, are pierced with a hole for suspension by a wire in the flue behind the damper, or at the bottom of the chimney, and the time occupied in melting recorded. Mr. Carmichael, from repeated observations under various circumstances, found that the temperature of the escaping products of these chimneys was uniformly 600 behind the dampers; tin melted at once, bismuth generally in less than a minute ; lead melted when the fires were in good condition, and zinc did not melt. CROSSNESS, METROPOLITAN BOARD OF WORKS. Engineer Sir JOSEPH BAZALGETTE. /?*# Commenced May, 1863 ; Completed January, 1865. Description. Square brick shaft with curved base on pedestal, with stone mouldings, surmounted by ornamental iron cap. Dimensions, Height, including foundations, to summit of iron cap 246' 7" ,, from ground line to top of stone moulding under iron cap . .177' o" Foundation bed below ground line 40' o" Outside dimensions, concrete foundation 30' 2" X 28' 6" ,, measurement at ground line square 26' 6" ,, parallel shaft square 12' o" Inside diameter ,, flue circumference 8' 3" Foundation. Foundation bed is 24' below ordnance datum. The concrete block is 16' in height, and upon it are laid two courses of 6" York landings before commencing footings to shaft. Detailed Examples of Existing Shafts. 85 Fire-brick Lining. The shaft is lined with Stourbridge fire-bricks for a height of 40'. Materials. Cement concrete (6 to i and 8 to i), 800 cubic yards ; bricks, about 400,000. Men. The bricklayers employed varied, but when above the curved portion 4 were engaged on the shaft. Progress. Varied very much, but the general run was 10' per week. Scaffolding Outside, cost about ^600. Cost. Approximate, 4,000. WOOLWICH ARSENAL, GUN FACTORY CHIMNEY. Description. Square pedestal, octagonal shaft. Dimensions , Height from ground line to top 170' o" ,, of pedestal above ground 30' o" Outside measurement of base at ground surface . . . 18' 9" ,, ,, bottom of shaft 13' i" Inside ,, 9' 4" Outside ,, at top 5' 6" Inside ,, ,, 4' o" Construction. The chimney is built up in 5 sections. The heights and thickness are as follows : 1st section . . . pedestal 30' high 3 bricks thick. 2nd ... shaft . 50' i\ 3 rd . . . . 30' 2 4th , . 30' i| Sth 3' I 170 ,, above ground. Cap. Stone, supplied by S. Trickett, Mill wall, London. MASSACHUSETTS, U.S.A., AMERICAN PRINT WORKS, FALLS RIVER, CHIMNEY SHAFT AND VENTILATOR. Figs. 44, 45, 46 and 47. Engineer . . . J. A. MILLER, New York. Height from ground line to top 160' o" Chimney proper internal diameter throughout .... 6' o" 86 Tall Chimney Construction. Hot Chamber. It will be seen upon reference to diagram No. 46 that at the base of the shaft an enlargement or " hot chamber," 20' high x 10' diameter is formed, into which the gases delivered by the flues are discharged. The object of this chamber is to allow the currents from the flues to be gradually diverted upwards, and is of more advantage when two or more flues discharge into the same chimney, and where there are consequently conflicting currents. This chamber is vertically of eliptical form, being contracted from 10' diameter at centre to 5' diameter at outlet. Chimney Proper. The circular chimney proper commences from the top of the hot chamber, and is internally 6' diameter throughout its entire height. The brickwork is increased in thickness downwards by external offsets, as see diagram No. 46, so as to avoid internal projections, which, in the engineer's opinion, cause eddies, and obstruct the upward flow of the gases. Outer Ventilating Shaft. The outer shaft is octagonal upon a square base, about 20' high. Four of the eight sides project for the width of a brick beyond the line of the others (see Figure 47). This projection, it is said, besides improving the architectural effect of the shaft, enables the work to be executed with fewer cut bricks than are ordinarily required in octagonal or circular shafts. Between the exterior of the inner shaft and the interior of the outer one there is an annular flue of an area of 2,200 square inches, which is used for ventilation purposes, being specially suitable by reason of the heated state of the air in it, caused by the high temperature of the gases in the inner shaft. Cap (Fig. 45). The inner shaft is terminated a little below the top of the outer one, and by piercing the latter with open- ings the wind passes through and impinges upon the sides of the cap of the inner shaft, the shape of which causes it (the wind) to be deflected upwards, and thus, by the action of induced currents, assists the draught rather than diminishes it, as is the case with the ordinary top, where it acts to a certain extent as a damper and checks the draught. The cast iron caps to both the inner and outer shafts are built up in sections, each of which is of such shape that its centre of gravity falls outside the inner line of the bases of the sections, and the sections thus tend to fall together and form a kind of arch. Each section is connected to that adjoining it by two bolts, but from the shape given to the sections they will maintain their position, even if the bolts are corroded away. The sections are provided at their bases with flanges, which grip the shaft both within and without, as see Fig. 45. Detailed Examples of Existing Shafts. 87 MR. W. D. BARKER, PATENT BRICK WORKS, WORCESTER. Architect, F. CHAMBERLAIN, Barnsley ; Builder, W. D. BARKER. Built in 1869, from March to July (about four months). Description. Circular brick chimney, outer and inner shafts. Dimensions^ Height, including foundations 164' o" ,, from ground surface to top 160' o" Diameter of circular brick foundation 24' o" Outside diameter at top of footings 13' 10" Inside 7' ;" Outside ,, ,, under cap 6' 9" Extreme ,, of cap 10' 6" Inside ,, ,, 4' 6" Foundation. The foundation bed is rock marl, 4' below ground surface, upon which the brick footings commence, and are carried up to ground level. Constrttction. The Outer Shaft from top of footings to a height of 22' is of 14" work, and from thence for a height of 1 10' (28' from top) is 9" in thickness. The alteration from 14" to 9" work is made by an external set back of half a brick, thus giving the appearance of a pedestal. The Inner Shaft for a height of 10' from footings is in 9" work, thence to within 28' from top is 4^" in thickness; at this height the outer and inner shafts merge into one, and are continued in 14" solid work to under cap. The inner shaft is every 10' in height bonded to the outer one by No. 12 radial brick ties. The shaft was built by day labour, under the supervision of Mr. Barker. Brickwork. 92,000 purposely made red bricks 9" x 4 J" X 3^" were used in the construction of this shaft, costing 265. per m. The whole of the bricks in the exterior shaft were made to suit the radius of the stack. The lime and sand were ground together in a mill, and used almost hot. Bond. Three stretchers to one header. Weight. 390 tons = '86 ton pressure per square foot on foundation bed. Batter. The batter of the outer shaft is J" per yard, that of the inner shaft is -J" per yard. Scaffold. Inside. Tall Chimney Construction. Duty. One boiler and one Hoffman's brick kiln. Cap. The cap is of brick formed by a course of round end bricks 1 8" X 6" x 4", then two courses of white bricks cornered out, then two courses of ordinary red bricks, then a course of round ends 1 8" x 9 J" X 6", then gathered in and finished with half round coping 14" x 7". This work is in cement, and the large bricks were cut to the radius of the cap. Mr. Barker says this cap gives a pleasing finish to the shaft, and is excellent in its simplicity, and he cannot understand why heavy cast iron caps are adopted when a better effect can be obtained in brick- work. Lightning Conductor. Copper, costing about ^n fixed. WROUGHT IRON CHIMNEY, MESSRS. FRANCIS & Co., THE NINE ELMS CEMENT WORKS, CLIFFE CREEK, ROCHESTER. Erected, 1878 ; Designed by Mr. V. DE MICHELLE, C.E. ; Constructed by Messrs. FIELDING & PLATT, Gloucester. Description. The shaft is circular and parallel throughout, and is constructed as follows : Dimensions, Height from ground line to top 160' o" External diameter throughout 5' o" Internal ,, 4' 6" Wrought Iron Plates. The plates vary in thickness down- wards, from I" to f ". Fire-brick. The shaft is lined with 3" fire-brick its entire height. Wind Stays. The chimney is stayed against the wind by No. 4, 3f" steel guy ropes. Duty. This chimney was erected over the centre one in a row of nine cement kilns, which are all connected to shaft by a wrought iron horizontal flue 4' in diameter. Two additional kilns have since been added, and the chimney now carries off the gases from eleven cement kilns. Chimney Base. Round the outside of centre kiln on ground level is fixed a cast iron curb or base plate. On this base stand four cast iron standards or supports, having their lower ends butting into and secured to base plate. These standards incline Detailed Examples of Existing Shafts. 89 inwards until their upper ends meet to support a cast iron circular chimney base, which forms the top of the centre kiln. The wrought iron chimney proper commences from top of this circular cast iron base, directly over which the 4' horizontal flue is connected to shaft. Construction (Novel Erection). A timber stage was erected at about level of kiln tops, and upon this stood the rivet fires. Four winches were worked on this stage, and to them were led guy ropes, after passing round blocks at convenient distances. A hydraulic press with a 4' stroke was then fixed over the centre kiln, and the top length of 20', which had previously been riveted up on the ground and raised to the stage level, was placed upon the ram. The ram was then pumped up, and the 20' length raised a height of 4', the guy ropes being slackened out to the required extent, as the 20' length gradually rose. A 4' ring of plating was then riveted on with f " snap head rivets, and the usual lap. The ram was then again pumped up, and the now 24' length raised the necessary height ; another ring of plates was then riveted on, and the operation repeated until the chimney had reached its required altitude. The Engineer says "The chimney answers its purpose admirably." On a bad foundation he would recommend the construction of an iron shaft, but on a good one, decidedly brick. Cost. About ;i,ooo, including long wrought iron flues. COTTON FACTORY, MEXICO. Description.- Chimney built of apparently sun-dried bricks, in use over twelve years, and in excellent condition. This shaft was built by Indians, is symmetrical, and appears to be well constructed. Height about 160' o" Bricks, size of 10" X 3" X 7" The above particulars were given at a meeting of the American Society of Civil Engineers, March 5th, 1884. At the same meeting a chimney was mentioned as being in successful use in Pennsylvania, U.S.A., which is generally known as the " crinoline chimney," being constructed of old rails. G go Tall Chimney Construction. MR. SHEKOLDEN'S PAPER MILL, ADESHAVO (NEAR THE TOWN OF KINESHMA), KOSTROMA GOVERNMENT, RUSSIA. Engineer .... V. T. GREGORY, Moscow. Description. Circular wrought iron shaft, brick pedestal. Erected March, 1874. Dimensions, Total height, including foundation 1 70' o" Height of brick pedestal above ground 14' o" Height of W.I. shaft 62 Archines = 144' 8" Total height from ground to top 158' 8" Diam. inside, at foundation, pedestal, and top of shaft 2 Archines = 4' 8" Outside measurement at brick foundation footings n' 8" Pedestal outside measurement at ground surface 9' 4" , at top -7' o" Thickness. The shaft is circular and parallel all the way up, and composed of plates varying in thickness downwards from T y tof. Duty. This chimney carries off the gases from the flues of five boilers, which give in the aggregate 250 nominal h.p. Wood fuel is used, and the chimney draught travels some distance and passes round a large wrought iron tube placed in flue as a water heater to feed boilers, consequently the heat at bottom of shaft is not so intense as to require any fire-brick lining to protect the shaft. Foundation. It was the intention of the owner to build a brick chimney, but finding the ground very bad he decided to have one in wrought iron. The foundation is of brickwork on gravel, and is carried to 1 1' 4" below ground level. Construction. The chimney was made at contractor's works, and brought to the mill in three parts and riveted together near site. The sizes of rivets used were f " diameter in lower portion and f" diameter at top, the lap of plates being about 2%'. The appliances used for lifting were a pair of sheer legs and two pairs of blocks. The legs were built on ground with pine timber cut in the adjoining woods, and bound together with wrought iron hoops and bolts ; then taken to pieces after each timber had been marked to its own place. The legs were then removed to the chimney site and erected so as to lean over centre of foundation. The blocks were then hooked to, and the tube lifted in bulk and placed on its brick pedestal. Detailed Examples of Existing Shafts. 91 The erection was carried out by Mr. J. P. Moorhouse, of Burnley, England, and the time occupied in lifting", after all preparations had been made, was ij hours. Mr. Moorhouse states "wrought iron chimneys are very common in Russia, and seem to give general satisfaction. They are used principally for small or medium sized works of all sorts, the first cost being much in their favour." The Russian climate being much drier is more favourable to wrought iron shafts than the English. ABBEY MILLS PUMPING STATION, METROPOLITAN BOARD OF WORKS. Engineer, SIR JOSEPH BAZALGETTE. Built, 1867 ; time occupied in building brick shaft from top of stone base to underside of stone head, 2Oth July, 1867, to Qth Nov., 1867. Description. Octagonal brick shaft with curved base on massive square stone moulded pedestal; top formed of stone, surmounted by large ornamental iron cap. Dimensions. Taken from contract drawing, Height, including foundations to summit of iron cap . .212' o" Foundation below ground line 21' o" Height from ground line to top of stone cap . . . .158' 3" Height of pedestal above ground line 30' 9" Outside measurement, square concrete foundation ... 43' o" square brick footings 39' 6" at ground line 30' 6" top of pedestal 17' 6" top of shaft under cap . . . . 10' 3" Inside throughout, except at set offs . . 8' o" Foundation. The foundation bed is 6' below Ordnance Datum. The concrete layer is 6' deep and 37' 6" x 3 7' 6"; it is, however, carried out on each side 2' 9" to form foundation to base buttresses. Upon the concrete the footings are constructed for a height of 4', having four steps and set offs. Shaft. From pedestal to underside of cap is constructed in three sections, as follows : ist section, including curved base 40' high tapering from 4' 4^" to i' io|" thick. 2nd 39' i' 6" 3^ , 39' . I' ij" Brickwork. From stone base to underside of stone head, time, Bricklayers 525 days. Labourers 590 ,, This equals a cost of 8 per rod for labour only. 92 Tall Chimney Construction. Portland Stone. Stone cap, 900 cubic feet or 60 tons, supplied by S. Trickett, Millwall. Time for raising and fixing only Masons 72 days. Labourers 144 ,, This equals about is. 2d. per cubic foot. Scaffolding, &c. The means used for raising the bricks and stone on shaft were by a small donkey engine, chains being fixed round wheels at top and bottom of shaft, after reaching 50' in height. No. of scaffold poles used Shaft 428 Barrow lift 18 446 total. No. of cords used Standards 324 Barrow lift 54 Braces 216 Ledgers 544 1138 total cords. Iron Cap. Weight, 27 tons. This cap was ultimately removed during the examination and repair of top of shaft in November, 1883, owing to the chimney being very much fissured by cracks. The masonry at top was strengthened by three additional braces of iron. SALFORD CORPORATION SEWAGE WORKS. Fig. 74. Engineer, ARTHUR JACOBS, M.I.C.E. ; Builders, S. W. PILLING & Co. ; Built, 1883. Description. Octagonal brick shaft, on square ornamented pedestal. Dimensions, Total height, including foundations 180' 6" Height from ground line to top 156' 6" ,, of pedestal square and parallel 40' o" Outside measurement at ground line 17' 6" Inside , 5' 3" Outside , base of octagonal shaft . . . . 1 1' 6" Inside , ,, . 6' o" Outside , at top 8' 4" Inside , 5' 3" Detailed Examples of Existing Shafts. 93 Foundation Bed. Red sandstone. Construction^ Thicknesses, &c. Pedestal, 40' high, five bricks thick, exclusive of fire-brick. Shaft ist section 34' 6" high 3^ bricks. 2nd 31' 7" 3 3rd * 3i' 7" 4 4th 1 8' 10" 2 Height from ground line . . . .156' 6* The chimney was built slowly. The workmen constructed about 2' in height daily, and when each 6' was built the work was left to rest for a couple of days. Ordinary bricks, laid to Flemish bond, used in construction ; best pressed bricks used outside, and stock bricks on the inside. At angles purposely-made bricks were employed. No hoop iron used. Fire-brick Lining. This shaft has a fire-brick lining 40' high, 20' one brick thick and 20' \ brick, i" cavity being left between pedestal and fire-brick lining. Scaffold. Inside scaffold was used, consisting of No. 4 put- logs, covered with boards for platform. A small set of shear- legs above. Duty. The flues from No. 4 boilers are connected to shaft ; the boilers are 27' long x 7' diameter, with two flues to each boiler. MILE END SPOOL COTTON MILL, EAST NEWARK, N.J., U.S.A. Engineers . . . BABCOCK & WILCOX COMPANY, New York. Description. Octagonal brick shaft, on square brick base, surmounted by ornamental cap. Dimensions, Height above footings 161' 6" ,, above ground line 150' o" ,, of square base above ground 30' o" Outside measurement, parallel square base 1 7' o" foot of shaft 16' 6" at top 12' o" Inside ,, throughout, except at off sets . . 10' o" 94 Tall Chimney Construction. Pedestal. The square base extends n' 6" below and 30' above ground line. It measures outside 17' x 17' its entire height, and the walls are 32" in thickness. Shaft. Above the square base the shaft is gradually stepped at the corners until the shaft is octagonal in form. It is built in four sections, as follows : ist section, including stepping . 30' high 24" thick. 2nd 30' 20" 3rd 30' 16" 4th including cap . . . 30' 12" Inner Shaft. An inner shaft is constructed for a height of 80' above ground line, as follows : 1st section 50' high 9" thick. 2nd 30' 4|" It is 10' diameter inside, thus leaving a cavity at the angles between itself and the brickwork of square pedestal and octagonal shaft. A wall across the circular flue at the base of the chimney, is built diagonally for the purpose of giving a larger and easier line from the horizontal to the vertical flue. It is also intended to prevent the two currents of gases from interfering with each other until they begin to travel in the same direction. Batter. i in 53-3. Duty and Flues. The boiler plant when complete will be composed of two sets or divisions of 1,248 h.p. each. The right hand division remains vacant for the present, the one at the left being all that will be necessary for some time to come. The entire plant will consist of six independent batteries of boilers. Each battery is composed of two independent boilers of 208 h.p. each. The flue for conveying the products of combustion from the boilers to the chimney is double, and the gases can either be thrown into a direct flue underneath the economizer to the chimney, or can be passed up through an 8' x 5' damper, thence across the economizer into the stack. Plan. Experience has demonstrated that it is best to divide the economizer into two parts, as it makes the flues more direct, and allows one to be in use while the other is being cleaned or repaired, as may occur in an emergency. Further- more, this arrangement makes a more symmetrical plant. The ground level of the boiler-house is the street level, and a 7' door in front of the boilers is built for dumping the coal from the street directly into the boiler-room. Cap. The cap commences 1 2 'from the top, and is constructed for a height of 8' in brickwork, the remaining 4' being in stone, the whole forming a neat but ornamental cap. Detailed Examples of Existing Shafts. 95 EASTBOURNE WATER WORKS CHIMNEY. Fig. 76. Engineer, G. A. WALLIS, M.I.C.E. ; Architect, H. CuRREY, F.R.I.B.A. Built, 1881-2 ; 5 months occupied in building. Description. Square brick shaft, buttressed. Dimensions, Total height, including foundation 165' o" Height from ground line to top 150' o" Concrete foundation square 30' o" deep 8' o" Outside measurement at ground surface 12' o" Inside ,, ,, ,, 6' o" Outside ,, at top 6' o" Inside 3' o" Foundation Bed. Chalk. Buttresses. This shaft has two buttresses on each side, making a total of eight ; they are 3' in thickness, and extend to a height of 34'. Batter. i in 50. Materials. 134,850 bricks were used in the construction of this chimney. Weight. 542 J tons. Scaffold. Outside scaffolding was used at a cost of ^101. 53. Lightning Conductor. Copper tape. MESSRS. PROCKTER & BEVINGTON, GLUE AND SIZE WORKS, BERMONDSEY. Architects, GEO. ELKINGTON & SON ; Builder, BENJAMIN WELLS. Built, 1 88 1 -2 ; from June to January, 8 months. Description. Circular. Dimensions, Total height, including foundations 161' 6" Height from ground line to top 150' o" Outside measurement of square foundation 24' o" Inside 6' o" Outside Inside Outside Inside at ground surface 16' o" 6' o" at top 6' o" 4' 6" Tall Chimney Construction. Construction. The bond of brickwork is principally English. The shaft contains 38 rods reduced brickwork. Ordinary best stock bricks were used. Scaffold. Outside scaffolding was used for first 100', then inside scaffold to top. Lightning Conductor. stranded rope. The conductor is of f" copper LONDON AND NORTH-WESTERN RAILWAY, BROAD STREET GOODS STATION, LONDON. Fig- 75- Builder JOHN JAY. Description. Octagonal brick, erected 1867, for boilers. Dimensions, Height, including brick footings 1 70' 7" ,, from ground line to top 150' o" of footings 14' o" Base ,, 36' o" X 22' i|" Outside measurement over sides at ground line . . . . 15' o" Inside ,, of fire-brick shaft 4' 9" Height of 9" fire-brick shaft from base 55' 3" Outside measurement under cap at top 8' o" at top of shaft 7' 6" Inside 4' 6" Thicknesses. The octagonal shaft is built up in eight sections, from top of footings 6' 7" below ground, as follows : 1st section 9' 6" high 4' 4^" thick. 2nd 16' o" 3' ii" 3 r d 16' o" 3' 6|" 4th 21' 6" 3' i|" 5th 21' 6" 2' 9" 6th ..... 27' o" 2' 3 |" 7th 22' 6" i' ii" , 8th 22' 7" i' 6" Total height above footings 156' 7" Batter. i in 40. Detailed Examples of Existing Shafts. 97 MESSRS. E. BROOKS & SONS, FIELDHOUSE FIRE-CLAY WORKS, HUDDERSFIELD. Figs. 48 to 53 inclusive. Architect, B. STOCKS, Huddersfield; Builders > E. BROOKS & SONS. Built, 1878. Description. Circular brick chimney, outer and inner shafts. Dimensions, Height, including foundations 158' 3" from flue invert to top 150' o" Diameter of circular concrete foundation 24' 4" Outside diameter top of footings 16' 8" Inside 7' o" Outside at top 9' 4" Inside , 7' o" Foundation. A bed of concrete 24' 4" in diameter forms the base for foundation footings. Upon this are laid eight stones, 1 2" thick and each 8' across, leaving a 1 2" margin of concrete, and a circular space at centre 6' 4" in diameter, which is filled in with brickwork. Upon this stone base the brickwork footings commence 21' 2" in diameter, and are stepped in nine off sets, each 6" in height, terminating 16' 8" in diameter at top. See Figs. 48 and 49. Flues. There are four flue openings at base of shaft, 7' high x 2' 6" wide, with 9" fire-brick sides and inverts, and 14" fire-brick top arches. Outer Shaft. The shaft between the flue openings is built up solid. From level of top of 14'' arches to flues the outer shaft commences, with heights and thicknesses as follows : ist section 36' high 18" thick. 2nd 45' 14" 3^ 27' 9" At this height it joins the inner shaft, and the work is con- tinued solid to top, 3 4' high, and terminating 14" thick. Inner Shaft. This commences at level of top of flue arches 58' 10" high 14" thick. 48' o" 9" At this height it joins the outer shaft, as above-mentioned. The inner shaft for a height of 58' 10" is lined with fire- brick, bonded into brickwork every fourth course. The top 48' is not lined. 98 Tall Chimney Construction. Cavity. The cavity between inner and outer shafts is divided by eight tie walls 14" thick for height of 14" work of outer shaft, and 9" thick to junction of shafts. Each of the eight spaces thus formed is provided with means of ventilation by one opening at base and one at top 12" square, each opening having a cast iron grating built into brickwork. See Figs. 49, 51 and 53. Batter. External " per yard or i in 41*1; internal flue, parallel. Cap. A fire-brick course 14" thick x 12" high forms the only finish to shaft. It was at first intended to construct a 2' string course 4-6 from top to add to the appearance of shaft, but even this Messrs. Brooks omitted being of opinion that the plainer the termina- tion the better. MESSRS. E. LACON & SONS, BREWERS, GREAT YARMOUTH. Engineer and Builder . . . Mr. WAKEFiELti, London. Built 1838 ; three months occupied in building. Description. Square brick panelled pedestal with two 4!" set-offs for plinths. Dimensions, Original height, including foundation 160' o" from ground line to top 140' o" Present 100' o" Outside measurement at ground line, square 10' 6" Scaffold. Inside scaffolding used in erection. Remarks. When completed this shaft was 140' high from ground line, but about 23 years ago it became so bent by strong north winds that the proprietors had 40' taken off, and it now stands loo'high. Detailed Examples of Existing Shafts. 99 MESSRS. W.MACFARLANE & Co., SARACEN FOUNDRY, GLASGOW. No. 2 SHAFTS. Engineer, JAS. BOUCHER ; Builders, ROBERT CORBET & SON. , 2 Possil Park. Washington Street Round. Square. Height, including foundation . . . MC*' II0|' above .... 134' IDS' 130' Outside measurement at foundation . . 9' ll Inside . . 6' 7 Outside at ground surface 9' Inside 6' Outside at top . . . . 9' 8' Inside ,, .... 5' 51' Cost of scaffold ^4. los. Description of do Inside. Inside. ^432 > 2 Tl Built 1873 1862 Foundation bed Clay. CARBON FERTILIZER MANURE COMPANY, OLDHAM. Architect, A. PAYNE, F.R.I.B. A. ; Builders, Messrs. NEILL & SONS. Built, 1874 ; fi ve months occupied, exclusive of foundation. Description. Brick, square pedestal, round shaft Dimensions, Height, including foundation 165' o" above concrete ,, 142' 6" ,, ,, ground line 133' o" Outside measurement, square concrete 23' o" Inside at base 7' o" Outside ,, square pedestal 13' 10" ,, diameter at top 7' 3" Inside 5' o" Foundation. The foundation bed was very bad. A concrete block of considerable depth formed the base for footings, which were square externally, of brick, and 4' 6" in height. loo Tall Chimney Construction. Construction. The chimney above concrete is composed of nine sections, as follows : Height. 1st sec. . Footings 4' 6" Pedestal. 2nd . Brick in mortar, 13' 10" sq. externally, partly below ground . 17' o" 3rd . Brick in mortar, 12' 4" sq. externally, with hoop iron bond . 23' o" Shaft. 4th . Moulded circular brick base to shaft in cement 4' o" 5th , . Brick in cement, bonded with hoop iron, 9' 6" external diam. . 17' o" 6th 7th 8th 9th Brick in mortar 9' diam., hoop iron bond at intervals .... 22' o" Brick in cement 8' 9" diam., with hoop iron bond n' o" Brick in mortar 8' 3" diam., with hoop iron bond 22' o" Brick in cement, including cap, with hoop iron bond .... 22' o" Height above concrete . . .142' 6" Shaft. The shaft is composed of two set offs expanding upwards. Hoop Iron Bond. The hoop iron was used in several courses close together, and several lengths in each course. Brick in Cement. The Architect had the cement rings constructed " to give greater strength to the shaft, and to obviate cracks, cement having greater adhesive power than ordinary mortar." Fire-brick Lining. The shaft is partly lined with fire-brick, but the heat is not expected to be excessive, it being mostly used for hypocaust drying rooms. Cap. The cap has a considerable projection, and is carried by a stout ring of York stones well cramped together, resting on brick corbels. Lightning Conductor. Copper tape, insulated. MESSRS. GROUT & Co., SILK CRAPE WORKS, GREAT YARMOUTH. Built, 1829-30; 12 months occupied in construction. Description. Square brick chimney. Dimensions^ > Height from ground line to top 127' 6" Outside measurement at foundation 18' o" ,, ,, at ground surface 12' 6" Inside 6' 10" Outside ,, at top 3' 6" Inside it 2' o" Detailed Examples of Existing Shafts. 101 Foundation Bed. Sand. Thicknesses. The shaft is composed of eight sections, as follows : Plinth from ground line . . 3' o" high 3' 6" thick. ist section 12' 2nd 3rd 4th 5th 6th 7th 8th Height from ground line 127' 6" Scaffold. Inside scaffolding used. Batter. i in 28. Remarks. The brickwork to top of plinth was built in Portland cement. On the igth July, 1884, at 9.30 a.m., the chimney was struck by lightning, damaging the shaft to the amount of T1' 3" t 2' 6" 17' V 2' 2" 1C' 9" I' TO" 16' T' 6" ?v i' 2" i V 6" o" cap and blocking i' II" 9" >j PENNSYLVANIA RAILROAD, WEST PHILADELPHIA SHOPS, U.S.A. Figs. 54 to 59 inclusive. Engineer JOSEPH M. WILSON, Philadelphia. Description. Brick chimney, circular pedestal, shaft of an eight pointed star section. Dimensions, Height from ground line 121' 8" of pedestal above ground. . 7' 8" Outside diameter of pedestal 13' o" ,, ,, of shaft, over points, under cap ... 8' 9" Inside diameter throughout 4' o" Flue invert below ground 5' o" Foundation. Stone. Section. This shaft is remarkable, inasmuch as its section has the form of an eight pointed star, with a circular inner shaft, thus leaving the points of the star hollow. These hollow spaces run from 2' above ground line to top, and have air open- ings in the brickwork at base and in the cast iron cap at top. IO2 Tall Chimney Construction. Outer Shaft and Pedestal. The heights and thicknesses of the brickwork, starting from top of plinth, are as follows : 1st section, including pedestal 36' high i' 6" thick. 2nd ...... 36' i' 2" 3rd to 12' from top . 35!',, 9" Inner Shaft. Two feet from ground line to top : 1st section 5' 3" high i' n" thick. 2nd 50' o" i' 6" 3rd; 40' o" i' 2" 4th 24' 5" 9" Brick Lining. An inner lining 4^" thick runs throughout the stack, but is not bonded to the inner shaft, for 17' from flue invert the lining is of fire-brick. Cap (Fig. 59). At a height of 1 2' from the top the brickwork is gradually stepped outward until it measures 1 4' in diameter ; into this bell-shaped top the eight points gradually die away, and upon it a cast iron hollow cap, 3' in height, is placed, cover- ing the brickwork of inner shaft, and having outlets for the escape of the heated air from the eight cavities before mentioned. WOOLWICH ARSENAL. Dimensions, Height above ground 120' 6" Outside measurement at base 10' 9" at top 4' 9" Construction. This chimney is built up in five sections, the heights and thicknesses of which are as follows : ist section 16' 6" high 3 bricks thick. 2nd 25' 3" 2i 3rd 25' 3" 2 4th 25' 3" l| 5th 28' 3" i 120' 6" high above ground. The top 28' 3* was built in cement. Scaffold. Erected independently of shaft, without putlogs. MESSRS. REID & Co., BREWERS, CLERKENWELL ROAD, LONDON. Engineer, GEO. SCAMMELL ; Builders, Messrs. CUBITT & Co. Description. Square brick pedestal on concrete foundation about 52' high, including 9' stone moulding. Round brick jshaft. Detailed Examples of Existing Shafts. 103 Dimensions, Total height, including foundation 142' 3" Height from ground line to top 120' o" Outside measurement of square concrete foundation . .22' o" ,, square footings 20' 3" Height of footings 5' 9" Outside measurement at ground surface 12' o" Inside 5' 3" ,, ,, at outlet top of cap 5' 8" Foundation Bed. Gravel. Construction. The walls of pedestal are constructed in brickwork 2' yj" thick (3^ bricks), then the first 21' of circular shaft 2 1 bricks thick, next height of 23' in 2 bricks thick, and topmost height of 12' in ij bricks thick. The top of shaft is formed by a 6' length of stone work, and then terminates with a cast iron cap about 5' high, fitted together in segments, bolted internally. The outlet formed by this cap is bell-mouthed, and is 5' 8" internal diameter. YALE LOCK MANUFACTURING COMPANY, STAMFORD, CONNECTICUT, U.S.A. Figs. 60 to 64 inclusive. Engineer, HENRY R. TOWNE. Built, 1881. Description. Square brick shaft on panelled pedestal. DimensionSy Height, including foundation 126' from ground line 120' of pedestal above ground 18' of shaft above pedestal 102' Outside measurement at base of foundation 15' at top of n' 10" at ground line n' 10" at top of pedestal n' o" 4' o" at base of shaft 10' 4" 4' o" at top under cap 6' i" 4' 9" Inside Outside Inside Outside Inside Foundation. The foundation is shallow, for the reason that a bed of hard gravel was struck a few feet below the surface of the ground, which formed a good basis for the chimney founda- tion. The first course of stone was composed of large selected IO4 Tall Chimney Construction. flat boulders 4' X 4', upon top of which were placed other smaller ones laid in Portland cement. The upper part was built of small stones grouted with cement. Outer Shaft. This is built up in four sections, viz. : ist section 7' high 20" thick. 2nd 25' 16" 3rd 31' 12" 4th 34^' 8" Inner Shaft (Fig. 60). This is constructed in three sections, commencing 22' 6" above ground line, as follows : ist section 9' 9" high 12" thick. 2nd 36' 3" 8" 3rd 30' o" 4" The inner shaft is built independently of the outer one, its inside measurement at base being 4' and at top 4' 6". From this it will be seen the inner shaft has an outward batter of -04" in one foot, and was so designed that it affords free escape for the products of combustion, as they expand in their progress upward. At the summit of this inner shaft is a sheet iron hopper top, No. 1 8 W. G., which covers the sharp off set that would otherwise occur to affect the draught. Iron Bond. Tie irons, consisting of pieces of flat hoop iron, with each end bent downwards, were built into the walls all the way up, at distances of 3' apart. The inside walls also had tie irons up to termination of 8" work. Iron Ladder. An iron inside ladder extends from the bottom to the top, and is formed by building in short bars of round iron J" in diameter across one of the corners of the square interior (see Figs. 63 and 64!. An iron ladder is suspended from one of these bars to reach over the sheet-iron hopper top of the inner shaft (see Fig. 60). Fire-brick. There is a wall of fire-brick 8' high (see Fig. 60) on the inside of chimney, where the flue enters pedestal. This wall was put up after the chimney was completed, and may be re-placed at any time without disturbing the outer walls. There is a 2" space between the fire-brick and the brickwork of the chimney proper. Batter. Pedestal, parallel. Outer shaft, J" in i' or i in 48. Duty, &c. This shaft was constructed to run six horizontal tubular boilers, 54" in diameter and 15' long. Each boiler has 54 tubes 3" in diameter, with a grate 4' long x 4' 6" wide, and is rated at 65 h.p. The opening from each boiler to flue is Detailed Examples of Existing Shafts. 105 13" X 33", while the main sheet iron flue is 36" in diameter. The boilers, in addition to furnishing steam to drive a 20" x 42" stationary engine of the Corliss type, have to supply steam for heating extensive buildings, and for other purposes. EXTRACTS FROM SPECIFICATION. 1. Foundation. That the Company will have built and finished, ready for the brickwork, a proper stone foundation, and will assume all responsibility therefor. 2. Bricks. That said Company will furnish, delivered on the ground, as the contractor may require them, all bricks required in the construction of the chimney, and that the con- tractor will carefully select bricks of good and uniform colour for the external faces of the chimney. 3. Materials. That the contractor will furnish all other materials required, including lime and sand, all of which shall be of thoroughly good quality of their respective kinds, special care being exercised to secure a strong and durable mortar. 4. Brickwork. That all portions of the chimney shall be built in strict accordance with the plans and sections shewn on the drawings attached hereto. The bricks for outside faces of walls to be selected as specified above, and no swelled, rotten, or unsound brick to be used in any part of the structure. All bricks to be well wetted before laying, and to be laid with flushed solid joints, leaving no empty spaces in the walls, except where called for on the plans. All courses to be run perfectly level and straight. The batter of outside walls to be exactly one- fourth inch to the foot, and the greatest care to be taken that a uniform batter is preserved on each of the four faces, so that the chimney, when completed, shall be exactly perpendicular. Special pains must also be taken to carry each of the outside angles exactly vertical and to avoid giving them any " twist." The joints of the exterior walls of the chimney and of the interior walls of the vertical flue (that is, those with which the smoke will come in contact) to be filled fully flush with faces of bricks when struck with the trowel, and every joint, both horizontal and vertical, to be neatly and carefully" rubbed smooth with a "jointer," so as to leave the faces of the walls perfectly smooth and flush. 5. Bonding Irons. That the Company will furnish proper bonding strips of hoop iron, cut to lengths required, and that the contractor will lay these strips in both the inner and outer walls H lo6 Tall Chimney Construction. of the chimney, at vertical intervals of about three feet, as may be directed by the Company, the ends of each bonding iron being bent so as to engage with the brickwork and assist in tying it firmly together. 6. Ladder. That the Company will furnish, and the con- tractor build in place, in one corner of the inside flue, iron bars, to constitute a steps or ladder for gaining access to the top of the chimney. These bars to be placed diagonally across one of the corners and at vertical intervals of about 1 8". 7. Openings. That the contractor will set and build into the chimney, as shewn on the drawing, an iron cleaning door (to be furnished by the Company), and will also construct two circular flue openings of the form and position shewn by the drawing. 8. Caps. That the Company will furnish, delivered on the ground, a cast iron cap or funnel, to be placed on the top of the inside lining or flue, as shewn by the drawing, and also cast iron cap, in four pieces (complete with joint plates) to form the final finish on top of chimney, the contractor to raise these caps and carefully set them in their proper positions. 9. Fire-bricks. That the contractor will construct a fire- brick lining (the joints to be carefully laid with fire-clay) near the base of chimney, as shewn on the drawings. This fire-brick lining to be laid independently of the surrounding walls, so that it shall not carry any part of the weight of the chimney, and so that it may be removed and renewed without disturbing the surrounding walls. The fire-bricks and clay to be furnished by the Company. 10. General. That the contractor will provide all necessary scaffolding and will remove the same upon completion of the contract ; that the Company will make provision whereby the contractor can obtain a supply of water by a line of hose (to be furnished by the contractor), not exceeding 100' in length; that the contractor will exercise constant supervision of the work while in progress, and will, to the best of his ability, construct and complete the work in a thorough and workmanlike manner throughout, it being the intention of this contract to secure the construction of said chimney in as perfect a manner as possible. Contract Price. 1,250 dollars, or 2 60. 8s. Detailed Examples oj Existing Shafts. 107 PHOENIX BOLT AND NUT COMPANY, HANDSWORTH, BIRMINGHAM. Architect, YEOVILLE THOMASON; Builders, W. PARKER & SON. Built, 1871. No. i. No. 2. Description, brick Octagonal. Octagonal. Total height, including foundation ... 120' o" 100' o" Height from ground line 1 10' o" 90' o" Outside measurement at foundation . . 20' o" 16' o" ,, ,, at ground line . . n' o" 8' 2" Inside ,, ,, . . 5' 6" 3' 6" Outside at top .... 6' 6" 4' 6" Inside .... 5' o" 3' o" Foundation bed Marl. Marl. SURREY COMMERCIAL DOCKS, ROTHERHITHE. Engineer, JAS. A. McCoNNOCHiE ; Builders, HOLLAND & HANNEN. Built, 1883 ; April to August inclusive. Description. Square brick pedestal with panelled sides, circular brick shaft. Dimensions, Height, including foundation 132' 2" ,, from ground line 108' 8" Outside measurement, concrete bed, square 19' 6" ,, ,, brick footings ,, ..... 17' 6" ,, ,, at ground line ,, 13' 9" diameter at base of shaft, circular 10' o" Inside 5' 6" Outside ,, at top, under cap 7' 3" Inside 5' 9" Foundation. The foundation bed is gravel 23' 6" below ground line. A square column of cement concrete 19' 6" x 19' 6" is carried to within 4' 6" of ground line, at which height the footings commence. Fire-brick Lining. A fire-brick lining is built up 34' 6" in height, in contact with brickwork of chimney proper but not bonded to same. Construction. The chimney has a square pedestal with panelled sides, brickwork 3' thick, 33' 4" high from bottom of brick footings to top of Portland stone moulding at base of shaft. io8 Tall Chimney Construction. The shaft is built in Old English bond with all headers on external face of circular work, and is constructed in four sections, with thicknesses as follows : ist section 23' n"highi' io|" thick. 2nd 20' o" i' 6" 3rd 20' o" i' ii" 4th 13' 4" 9" The brickwork is then stepped out and surmounted by a moulded Portland stone cap i' 10" deep. The stones forming cap are held together by a wrought iron strap. Scaffold. Outside. Batter. 4^" in 20', or i in 53. Capacity. The fumes from No. 8 boilers are carried away by this shaft, and it is intended to serve engines of 430 h.p. Lightning Conductor. Copper tape. Cost, including fixing, ^17. 135. 3d. SOUTH METROPOLITAN GAS WORKS, RETORT-HOUSE SHAFT, OLD KENT ROAD, LONDON. Figs. 65 to 68 inclusive. Engineer, G. LIVESEY, M.I.C.E. ; Contractor, MORKLAND, Old Street, St. Luke's. Built . 1862. Description. Square brick shaft, built parallel the entire height and buttressed on the four sides, as see illustrations. Dimensions, Height, including foundation . . . 116' o" ,, from ground line to top 108' o" Concrete foundation 1 7' o" square X 5' o" Outside measurement over buttresses at ground line . . 12' o" ,, over square shaft ,, . . 7' 4" Inside of . . 5' o" Outside at top 6' 6" Inside 5' o" Foundation Bed. Gravel. Bond and Fire-brick Lining. The shaft is built in English bond, with stock bricks outside and fire-bricks inside, bonded together ; thus the courses of fire-bricks are alternately 9" and Detailed Examples of Existing Shafts. 109 4j". The fire-bricks were specially obtained for this chimney, of the same size as the stock bricks. Mr. Livesey has some- times adopted the plan of bonding the fire-bricks into the stocks every sixth to eighth course, where in using the ordinary sized fire-bricks the courses of the two coincide. Bricks. Total, about 80,000. Iron Bond. Bonds of 2" x J" flat iron, riveted at points of intersection, were built in the brickwork at intervals of 5' in height. (See Fig. 68.) Draught. The pressure at the base of this shaft when only forty-four furnaces were in action and a quantity of cold air entered through the dampers of the remaining ten was equal to 0*95" of water, and the quantity of heated air and gases discharged was about 470 cubic feet per second. Duty. This chimney when erected had fifty-four furnaces working into the shaft, and it was intended to connect twenty more. The shaft has been in constant use since its erection in 1862, and the brickwork has not burned away. Mr. Livesey' s opinion is that the heat is not sufficient to injure good fire-brick. Cap. Cast iron, weighing 2 tons. Copper Rim. On the top and sides of the 2' 3" blocking course, above" cap, there is a copper rim J" thick, put on at the suggestion of the contractor. Lightning Conductor. Copper wire. Cost. Complete, ^530. Remarks. In a similar chimney 70' high, built entirely of fire-brick for the engine-house, since the one above described, Mr. Livesey carried up the 14" work about 50' and then reduced it to 9" work to the top by a set off inside; thus the flue is larger at top than at base. TAMWORTH WATERWORKS. Architect, ALEX. PAYNE, F.R.I.B.A,,in conjunction with the Engineer, H. J. MARTEN, M.I.C.E. Builder, JOHN GARLICK, Birmingham. Built, 1880. Description. Brick, circular pedestal and shaft. no Tall Chimney Construction. Dimensions, Height above concrete foundation 14' 6" ground line 107' o" Outside diameter, circular pedestal n' 6" Inside ,, 6' 6" Outside base of shaft 8' 6" ,, top 6' 3" Inside 4' o" Foundation. Massive concrete foundation. Construction. The chimney above concrete is built up in eight sections as follows : Height. ist section Brick footings in mortar 4' 6" 2nd Brick pedestal n' 6" external diam. 28' o" Shaft. 3rd Base mouldings in cement 5' o" 4th 5th 6th 7 th 8th Brick in cement, 8' 6" external diam. . . . 10' o" ,, mortar, 8' o" ,, ,, ... 20' o" ,, cement, 7' 6" ',, ,, ... 10' o" mortar, 7' o" ... 17' o" ,, cement, including cap 20' o" Height above concrete . . .114' 6" The shaft has one internal set off. Hoop Iron Bond. Hoop irons were used in several courses close together and several lengths in each course. Brick in Cement. The architect had the cement rings con- structed " to give greater strength to the shaft and to obviate cracks, cement having greater adhesive power than ordinary mortar." Fire-brick Lining. Constructed 50' high. Cap. Constructed on a good ring of nped together. Lightning Conductor. Copper tape, insulated. Cap. Constructed on a good ring of York stones well cramped together. BOSTON, LINCOLNSHIRE, FLOUR MILL CHIMNEY SHAFT. Engineer, W. H. WHEELER, C.E., Borough Surveyor. Built, 1869-70. Description. Octagonal brick pedestal, circular shaft and cast iron cap. Detailed Examples of Existing Shafts. 1 1 1 Dimensions, Height from bottom of piles to top 135' 3" concrete foundation to top. . .119' 3" brick footings . . .in 1 3" ,, ,, ground line to top 105' 3" Outside measurement over sides of pedestal at ground line 1 1' 6" Inside of fire-brick shaft 4' 9" Outside Inside Outside Inside base of circular brick shaft ... 8' o" at top, under cap 4' 6" 3' o" Foundation Bed. The upper part of ground is silty clay, and the lower part hard clay and chalk stones. Construction. The chimney is built on No. 9 piles, 15' long by 1 2" square. The shoes of piles are 30' below floor line of mill. The piles at top are connected together with capsills, on which rests cross planking, then a concrete bed 15' X 15' X 8', on the top of which the brick footings commence. The octagonal pedestal is 20' high above floor level of mill and has Bramley Fall stone quoins. The circular shaft has a stone base moulding 3' 9" in height. The first 3' of shaft at base above moulding and the first 9', measuring from under cap and mouldings at top, are built in cement. The cap is of cast iron i" thick, 9" wide, 9" deep inside and 3" deep outside, 4' 6" external diameter ; constructed in three segments, bolted together with internal flanges. Materials. Brickwork, 16 rods. Bramley Fall stone, 740 cubic feet. Fire-brick Lining. The inner shaft of fire-brick is 40' high from ground line, built in 4 J" work. Cost. 350. A. GORDON & Co., CALEDONIAN ROAD, BREWERY, LONDON, N. Fig. 77. Engineer, C. PANTING ; Builders, WILLIAMS & SONS. Built, 1867; 3 to 4 months occupied in construction. Description. Octagonal brick pedestal, circular brick shaft. H2 Tall Chimney Construction. Dimensions, Height, including foundation ........... 1 14' o" ,, from ground line to top .......... 100' o" Outside measurement, square concrete foundation 4' o" thick 18' o" ,, base of brick footings ...... 14' o" ,, at ground surface ....... n' 3" Inside of fire-brick lining ....... 3' 6" Outside at base of shaft ........ 7' 3" Inside ........ 3' 6" Outside at top, over C.I. cap ...... 4' 7" Inside ........... 3' o" Footings. The footings are stepped upwards from 1 4' square to n' 7j", in seven courses; from this height the footings in thirteen courses are stepped at the four corners until they work into the octagon pedestal at ground line. Pedestal. Octagonal, panelled on each face, and 25' high from ground line, including a stone cornice, from which starts the circular shaft. Shaft. The shaft is constructed in four sections with thick- nesses as follows : ist section ....... 21' high i' io|" thick. 2nd ....... 15' i' 6" 4th ....... 24' 9" Batter. Shaft 10' vertical, 15' i in 60, 50' i in 42 nearly. Cap (Fig. 77). The shaft has a cast iron terminal 5' 6" high, of J" metal, made in segments and bolted together by internal flanges. It was painted in three coats of good oil colour, the last coat being Portland cement in oil. Cost. 440. DONCASTER LOCAL BOARD OF HEALTH, SEWAGE IRRIGATION WORKS. Engineer B. S. BRUNDELL. Description. Square brick pedestal, surmounted with square panelled shaft. Detailed Examples of Existing Shafts. 113 Dimensions, Total height, including foundation 112' 9" Height from ground to top 100' o" Outside dimension at foundation, square 18' o" ,, , at bottom of footings, square . . . 14' 3" , at ground line 9' 9" Inside 3' 11" Outside at commencement of shaft .... 7' 9" Inside .... 3' II" Outside under cap 6' i" Inside ,, 3' 9" Pedestal. This is if high, 2' 5" thick brickwork, with stone moulded plinth at base and moulded stone cornice at top Shaft. Square with panelled sides, erected in three sections as follows : 1st section ... 25' high 18" brickwork. 2nd ... 25' 14" 3rd ... 22' ,, to under cap 9" Batter. i in 86*4. Cap. Ornamental stone top, surmounted by a cast iron cap. GREAT NORTHERN RAILWAY. FARRINGDON STREET GOODS STATION. Engineer, R. JOHNSON, M.I.C.E. ; Builders, KIRK & RANDALL. Built, 1880; five weeks occupied in construction. Description. Round brick shaft on square pedestal. Dimensions, Total height, including foundations 102' 6" Height from ground line to top 96' 6" ,, of pedestal, including footings and stone base moulding to shaft. 23' 9" Outside measurement at ground line, square 8' 6" Inside circular 3' o" Outside base of shaft 7' 6" Inside ,, 3' o" Outside under cap 4' 6" Inside at outlet top of cap 2' 9" Foundation. Concrete base 12' 6" square x 3' deep on foundation bed of London clay. H4 Tall Chimney Construction. Materials and Weight, Tons. Cwt. In base there are 22,000 bricks, weight, including mortar . 86 o shaft 21,000 (radiating) 64 o ,, base, weight of stone no cap I 16 cast iron terminal of f" metal, in segments, bolted ) o I2 together by internal flanges } 163 8 Beart's patent perforated radiating bricks were used in the circular shaft, laid all headers on external face. Scaffold. Inside and outside. Construction. The walls of pedestal are 2' 9" thick, shaft is built up in five sections, as follows : 1st section 9' high 2' 3" thick. 2nd 16' ,, i' io" 3rd 16' i' 6" 4th 16' i' i|" 5th top . 9" Fire-brick Lining. This is carried up independent of pedestal, with about i" space for expansion, to a height of 21' 6" in 4J" work set in fire clay. Batter. The first 9' of circular shaft is built vertical, then i6'to a batter of i in 42, and the topmost length of 41' to underneath cap i in 37 nearly. Duty. To carry off the products of combustion from flues of No. 2 Cornish boilers 24' long x 6' external diameter, each having one internal tube 3' diameter. Lightning Conductor. Copper tape. Cost. Chimney complete, 400. MESSRS. PEEK, FREAN & Co.'s CHIMNEY, DRUMMOND ROAD, LONDON. Architects, SNOOKE & STOCK ; Builders, RIDER & SON. Built, 1866; two months occupied. Description. Square brick shaft and pedestal. Dimensions^ Total height, including foundation 99' 3" Height from ground line 9 1 ' 3" Outside measurement at ground line 10' o" Inside ,, 4' 9" Outside at top 7' 3" Inside 4' 6 " Detailed Examples of Existing Shafts. 115 Foundation Bed, Sandy gravel. Batter. i in 66. Bricks. 66 m. used in construction. Weight. 313 tons. Scaffold. Outside, costing ^60. Lightning Conductor. Stranded copper rope. Cost. Chimney complete, EXPERIMENTAL CHIMNEY, MAYFIELD PRINT WORKS, MANCHESTER. Engineer, R. ARMSTRONG; Owners, T. HOYLE & SONS. Builders . . . D. BELLHOUSE & SONS. Description. Brick, square foundations and pedestal ; shaft octagonal. Dimensions, Height, including foundations 100' o" ,, above ground line 90' o" level of fire-bars 88' o" ,, of pedestal above ground 18' o" ,, of shaft, including cap 72' o" Outside measurement base of footings 15' o" square pedestal 8' o" Inside Outside Inside Outside Inside ,, ,, octagonal flue 5' o" base of octagonal shaft . . 8' o" top of 4' 2 Shaft. This is octagonal both inside and outside, and is built up in two sections, viz. : ist section 36' high 19" thick. 2nd , 36' 9" Batter. i in 36. Capacity, &c. The internal capacity of the chimney, together with the short flue connecting it with the boiler to which it is attached, is about 50 cubic yards. 1 1 6 Tall Chimney Construction. The internal horizontal area of the outlet the narrowest part is about 1,000 square inches, which, as it was intended to make the shaft large enough for about 50 h.p., gives 20 square inches for each h.p., while there is about i cubic yard capacity in the chimney for each h.p. These proportions were adopted after averaging some of the best chimneys the engineer and proprietors were acquainted with in Lancashire. Cost. ,100. GREAT NORTHERN RAILWAY WOOL SHED, BRADFORD. Engineer, R. JOHNSON ; Builder, W. PICKARD & SON. Built, 1875. Description. Square stone shaft and pedestal. Dimensions, Height, including foundation 96' o" ,, above ground line 90' o" ,, of pedestal above ground line 19' o" Outside measurement at foundation 12' o" at ground line 9' o" 2' 9" above pedestal 6' 9" 2' 9" under cap 4' 10" Inside Outside Inside Outside Inside at top 2' 6" Fire-brick Lining. A 4j" fire-brick lining is constructed independently of the stone work to chimney, for the height of the pedestal. Duty. No. 4 boilers, each 24' long ; outside diameter, 6' ; internal flue diameter, 3'. Batter. Pedestal, parallel. Shaft, i in 66. Cost. ,260. Specification, Extract from. The site is on rock, and if in digging out for the foundations it is found that any faults or defective places exist, or if the rock has been quarried to a greater depth than that shewn for the footings, then the excava- tion is to be continued down to the solid, and a wall i' wider than the lowest course of footings is to be built up to the proper level for commencing the walls. This wall is to be of rubble masonry in Portland cement, or otherwise (as the Engineer may determine) of concrete composed of stone, broken to pass a 2" mesh, sand and Portland cement in the proportion of six of stone, two of sand and one of cement, to be properly mixed Detailed Examples of Existing Shafts. 117 together with the least quantity of water, and thrown into the trench from a height of at least 8'. The mortar is to be composed of the best Skipton or South Elmsall lime, as the Engineer may determine, and clean sharp sand, in the proportion of one of lime to two of sand, to be ground together in a mill worked by steam power on the ground, and only prepared as required for use. The walls are to be built with block in course, pitched face stone from the Bradford, Idle or Calverley quarries, as the Engineer may determine ; the stones to be not less than 1 1" on the beds and 6" on the joints, and not less than 7" or more than 14" in thickness ; the thicker courses at the bottom, and dimin- ishing gradually upwards ; thick courses in no case to be laid upon thin ones ; the whole to have boasted beds and joints. No natural faces must show in the wall. The footings are to be of rag stone. The chimney is to be carried up true and vertical upon its axis ; the base is to be lined inside with Stourbridge fire-brick to a height of 20' from bottom of flue. The shaft is to have an internal width at base of 2' 9" square, and at top 2' 6" square. At junction of shaft with pedestal it is to be corbelled over internally 6" all round. It is to be 2' thick at this point, and is to be gradually diminished to a thickness of i' 3" under cap. A space of 4" is to be left between the top of fire-brick lining and the bottom of corbelling in chimney, to allow of free expansion. The base moulds, necking and cap to chimney, together with all oversailings, strings and dentils, are to be executed in strict accordance with the drawing upon which all the sizes and forms are given. The cap and base mouldings are to be set in cement, the profiles of which are to be cleanly and sharply cut. The fire-bricks are to be of the best Stourbridge, or quality equal thereto, set in ground fire-clay, mixed with water to the consistency of cream. The bricks are to be dipped into the liquid fire-clay, laid in place and hammered together, so as to be when finished brick and brick. KENT WATER WORKS. Fig. 80. Engineer, W. MORRIS, M.I.C.E. ; Builders, J. RIDER & SON. Built, 1879 ; four months occupied in construction. Description. Brick, square pedestal, circular shaft, stone cap. n8 Tall Chimney Construction. Dimensions, Height, including foundation 97' 3" from ground line to top 90' o" Outside measurement at ground line 9' 3" Inside 4' o" Outside at base of circular shaft .... 7' 9" Inside , 4' o (> Outside at top, under cap 5' 6" Inside 3' 3" Foundation Bed. Loamy gravel on chalk. Pedestal. 22' high with Portland stone mouldings, i' io|" thick brickwork. Fire-brick Lining.* 20' high from ground line, 4^" thick ; no space between brickwork of pedestal and lining. Shaft. This is erected in three sections, viz. : 1st section . . . 21' high . . . I 10^" thick. 2nd ... 25' ... i 6" 3rd ... 22' with cap I i|" Wrought Iron Bond, &c. No. 1 1 rings of wrought iron bond are built into shaft at about 6' intervals, and No. i wrought angle iron band placed round circumference of Portland stone cap ; also No. 2 copper rings built into stone cap. Batter. i in 56. Scaffold. Outside. Lightning Conductor. Copper tape. Duty. No. 6, 35 h.p. boilers connected to shaft. G. TUCKER & SON, BRICKWORKS, &c., LOUGHBOROUGH, Designed and built by G. TUCKER & SON. Description. Square brick. Dimensions, Height, including foundation 95' o" ,, from ground line to top 85' o" Outside measurement at foundation 12' o" ,, at ground line 8' o" Inside 4' o" Outside at top 5' 6" Inside 4' o" Detailed Examples of Existing Shafts. 119 Foundation. Concrete on marl foundation bed. Bricks. Ordinary size, 9" X 4j" X 3". Batter. i in 68. Scaffold. Inside. Cap. Constructed of large purposely-made bricks. Lightning Conductor. Galvanised iron strand. Duty. To carry off smoke, &c., from two boilers and a Hoffman kiln. Cost. About ; 1 20. WEST END LAUNDRY COMPANY'S CHIMNEY, FULHAM, LONDON. Architect, WILLIAM C. STREET ; Builders^ WEST END LAUNDRY COMPANY. Built) 1883 (spring of year) ; time occupied, four months. Description. Brick, circular shaft, on square pedestal. Dimensions, Total height, including foundations ....... 97' 6" Height from ground line . .......... 80' o" Concrete foundation, square .......... 1 7' 6" ,, ,, in height ......... 6' o" Outside measurement base of footings ...... 13' 3" bottom of square pedestal . . . 10' 3" top ... 9' 9" base of circular shaft ..... 8' o" ..... 4' 3" top of shaft ........ 5' o" Inside Outside Inside 3' Foundation. The foundation bed is gravel, if 6" below ground level. Fire-brick Lining. The 9" fire-brick lining extends 22' from inside base of pedestal, and is built up square 2' 6" x 2' 6", leaving a cavity at base of 6" and top 4" between fire-brick and inside of pedestal. Pedestal. This is 2 7' 6" high from top of concrete, and has a batter of i in 52. I2O Tall Chimney Construction. Construction, Pedestal . . . . 27' 6" high 2' 7^" brickwork. Shaft ist section . 16' o" ,, i' loj" ,, 2nd ,, . 16' o" ,, i' 6" ,, 3rd . 16' o" i' ij" 4th . 16' o" 9" 91' 6" height from base of footings. Bricks. 59 m. ordinary bricks used in construction, laid to Flemish bond. Scaffold. Outside. Weight. 30 1 \ tons, giving a little less than one ton pressure per super foot on foundation bed. Duty. One boiler flue and one vapour flue connected to shaft; total h.p. 45. HASTINGS ELECTRIC LIGHT COMPANY'S CHIMNEY. Architect, E. W. J. HENNAH; Builder, A. VIDLER. Built, 1882-3 (August to March). Description. Square brick. Dimensions, Total height, including foundation 85' o" Height from ground line 78' o" Outside measurement at ground line 6' 6" Inside 3' 6" Outside ,, at top 4' o" Inside ,, 2' 6" Foundation. Concrete on clay and sandstone. Batter. The sides for the first 27' of shaft are parallel ; for the remainder of height they diminish to a batter of i in 41. Materials. 30 m. of ordinary bricks used in construction laid in cement. Measured work, 6 rods, 226' reduced brickwork. One course 4" stone on top. Weight. About 90 tons. Scaffold. Outside, costing about 1 7 extra. Duty. Two boilers working up to 200 h.p. Lightning Conductor. Copper tape, cost 12 fixed. Cost. Chimney and scaffold complete, 147. Detailed Examples of Existing Shafts. 121 MESSRS. ROBERT HEATH & SONS' CHIMNEY SHAFT, RAVENS- DALE IRON WORKS, TUNSTALL, STAFFORDSHIRE. Description. Circular wrought iron shaft, not spread at base. Dimensions, Height from ground line to top 75' o" Outside diameter at ground line 6' o" at top 6' o" Wrought Iron Plates. No. 75 wrought iron plates were used in the construction of this shaft, the thickness being " '. The plates have a lap of 2^", and are riveted together with f" cup-headed rivets. Fire-brick. The shaft is lined its entire height with fire- brick. Duty. The shaft carries off the fumes from three boilers. GEO. M. HAMMER & COMPANY, CROWN WORKS, BERMONDSEY, LONDON. Architect and Builder, G. M. HAMMER & Co. ; Built, 1882. Description. Brick, square pedestal, octagonal shaft. Dimensions, Height, including foundation 80' o" ,, from ground line to top 70' o" Portland cement, square concrete foundation 5' thick . . 14' o" Height of pedestal 15' o" Outside measurement at ground line 7' 4" Inside 2' 9" Outside ,, at base of octagonal shaft ... 5' 10" Inside . . . 2' 10" Outside ,, at top, under cap 4' o" Inside ,, 2' 6" Foundation Bed. Ballast. Shaft. This is built up in three sections, as follows :- 1st section 15' high 18" thick. 2nd ....... 20' 14" 3 rd M 20' 9" Scaffold. Outside. Batter. Pedestal, parallel. Shaft, i" in 5' or i in 60. I 122 Tall Chimney Construction. Weight. go tons including footings = '45 tons per square foot on concrete foundation. Lightning Conductor. Copper strand rope. y. No. i, 30 h.p. consider it capabL .2Q% complete. Duty. No. i, 30 h.p. boiler now connected, and the pro- prietors consider it capable of taking another 30 h.p. boiler. MESSRS. HARVEY & SON, BREWERY CHIMNEY, LEWES. Fig. 69. Architect, W. BRADFORD ; Builders, H. CARD & SON. Built, 1881 ; about two months occupied in construction. Description. Octagon brick on square pedestal. Dimensions, Total height, including foundations 85' o" Height from ground line 70' o" Outside measurement at ground line, square 6' 6" Inside 2' o" Outside at top 3' 6" Inside square 2' o" Foundation. Blue lias concrete, 1 7' x 1 6' x 8' 6" deep, on clay foundation bed. Scaffold. Outside. Cap, &c. Stone in cap and base, cost 70. Duty. To carry away smoke, &c., from one boiler of 25 h.p. Lightning Conductor. Copper rope, cost^io fixed. Cost. Chimney complete, ^270. CHAIN, CABLE AND ANCHOR TESTING WORKS, RIVER WEAR COMMISSIONERS, SUNDERLAND. Figs, jo and 71. Engineer, H. H. WAKE, M.I.C.E. ; Builder, GEO. GRAINGER. Built, 1873, at the rate of i' 6' in height per day. Description. Concrete, square pedestal, octagonal shaft. Detailed Examples of Existing Shafts. 123 Dimensions, Height, including foundation 62' 6" ,, above ground line 56' 6" ,, of pedestal above ground line 24' 9" ,, of shaft, including base moulding 31' 9" Concrete foundation square 12' o" Outside measurement at ground line 7' 6" Inside ,, ,, 4' o" Outside Inside Outside Inside base of shaft 5' 9" 3' 3" at top 3' 4" I' 10" Foundation. The foundation bed is "forced ground," con- sisting of sand and town rubbish tipped on to sea beach ; upon this is laid a concrete bed 12' x 12' x 6'. Pedestal. The square pedestal is outside 7' 6" X 7' 6" parallel. Inside to a height of 19' the flue is 4' o" square and parallel ; from this height (see Fig. 71) the insides of pedestal have a batter similar to that of the insides of octagonal shaft. Shaft, Base moulding . i' 9" Shaft and cap . 30' o" The shaft is built up in two sections, as follows : 1st section 15' high i' 3" thick. 2nd 15' 9" Fire-brick Lining. The lining extends the whole height of pedestal, viz., 24' 6" above ground, and is constructed in two thicknesses : 15' high 9" thick. 9 4i" There is no cavity or space between the fire-brick and the concrete of pedestal. Batter. i in 25. Materials. Concrete to foundation and pedestal was com- posed of i of Portland cement to 8 of shingle and sand. Concrete to shaft, i Portland cement to 5 gravel and sand. Out- side of chimney was coated with J" of cement, in the proportion of i cement to i sand, and joints struck to represent Ashlar. Construction. The shaft from base moulding was constructed in the following manner : Wood moulds 3' in height, formed of J" boards, hinged together in pairs at their outer edges, were constructed to form the quoins of the octagonal shaft. Standards 6' in height were used to bolt the outside moulds to the inside ones, and also to have 3' hold on the work already executed 124 Tall Chimney Construction. while a 3' length was being constructed. The batter of the shaft being uniform the quoin moulds did not require re-adjust- ing every 3' to suit the decreasing girth of the shaft, but this was provided for by wedge pieces being placed on each face working between the quoin moulds ; these wedges had to be reduced in width every 3'. When the quoin moulds had reached half the height of the shaft their edges on each face met, and wedges could not be inserted. The moulds were, therefore, re-adjusted, and a fresh set of wedges started ; the edges of quoin moulds met again at top. TAKING DOWN SHAFT. MESSRS. GILKES, WILSON, PEASE & Co., TEES IRON WORKS, MlDDLESBOROUGH. Figs. 72 and 73. Engineer Mr. CHAS. WOOD. TAKING DOWN A CHIMNEY SHAFT. An ingenious arrangement for facilitating the taking down of an old chimney shaft was here employed. In consequence of the shaft standing in a crowded position, the plan of letting it fall was inadmissible, and it had to be taken down from the top. The bricks had to be lowered with as little damage as possible, so that they might be used again for building purposes. Owing to the position of the chimney the bricks could not be thrown down outside, and if thrown down inside they would have been smashed, and if lowered by mechanical means the process would have been very tedious. Under these circumstances it was considered whether the bricks could not be allowed to fall by their own weight, and at the same time be cushioned sufficiently to break their fall and prevent damage. In order to do this an air-tight iron box was placed at the bottom of the chimney (Fig. 72). This box was fitted with an air-tight door, mounted on hinges and closing on an india- rubber face, against which it was tightened by a wedge. A wooden spout was then fixed on to the top of the box and carried up the chimney. It was 3 J" X 5" inside, made of Taking Down Shaft. 125 planks 1 1" thick, well nailed together with a little white lead on the edges, thus making it air-tight. The spout was made in about 12' lengths, and these were joined together by cast iron sockets or shoes (see Fig. 73), and caulked round with tarred yarn, the whole apparatus costing about 6. A. few stays were put inside the chimney to keep the spout steady. Steps were nailed upon the wooden spout by which the workmen ascended. The whole of the spouting being air- tight, if a brick filled the spout it would not descend, but as the size of a brick is 3" x 4 J" and the spout was 3 J" x 5", there was " space each side, through which the air could pass the brick freely, this space further allowing for any irregularity in the sizes of the bricks. The result was, that the bricks being cushioned in their fall, arrived at the base without damage. As soon as the box was full the man at the bottom rapped on the spout as a signal to stop, and then opened the air-tight door and removed the bricks inside. This being done he shut the door and signalled "all right" to the man at top. The workman at top lowered his own scaffold, and as the spout became too high he cut a piece off. If there were much mortar adhering to the bricks it was knocked off before putting the latter into the spout. Such mortar, &c., was allowed to fall inside the chimney and was afterwards wheeled out. The plan here described was, we believe, quite novel, and is certainly simple. There are, no doubt, many similar circum- stances under which it might be advantageously employed. STRAIGHTENING SHAFTS. CHIMNEY SHAFT, BINGLEY, NEAR BRADFORD. Straightening. This chimney, which was built at a cost of ; 2,000, was found some few years since to be 4' 6" out of the per- pendicular. The inclination was found to be due to the founda- tions having settled under the superincumbent mass of brickwork at one side. In this emergency it was advised that excavations should be made under the foundations at the other side until the chimney settled down to the same extent, and so brought itself back into the perpendicular. A well was actually dug beneath the higher side of the shaft, and supplied with water to favor 126 Tall Chimney Construction. the yielding of the rigid part of the foundation. This was a very perilous method of straightening the shaft, as after the ground had become sodden with the water and the foundation of the shaft undermined it would have been next to impossible to have stopped the subsidence at the desired point, and the shaft would have most likely fallen in an opposite direction to that in which it had previously leant. Before, however, any injurious effect had occurred the rectification was placed in the hands of Messrs. Sanderson, of Huddersfield. The first step was the restoration of the foundation to its original state ; the well was filled in and made firm with brickwork and concrete. A gap was next cut half through the bottom of the shaft on the side where no settlement had taken place by removing three courses of brickwork. As this was being effected strong screw- jacks of iron were inserted perpendicularly into the gap to take the pressure of the unsupported mass of brickwork. The jacks were i o"long, and iron plates i" thick were inserted above and below their ends to serve as temporary platforms. The jacks were inserted one after the other, a few inches apart, as the brickwork was cut away, and each one was adjusted by its regulating screw, so as to come at once into right bearing for sustaining its share of the weight. When the entire gap had been formed and all the screw-jacks inserted, the jacks were very slowly and gradually shortened as the weight did its work, and when the shaft had nearly settled back into its original perpendicular position, the portions of the gap, which lay between the screw-props, were filled in with masonry, the screws were, one after the other, removed, and masonry also put in their place. The making good of the work was com- menced before the shaft had quite reached the perpendicular, because it was known that a slight allowance must be made for a small compression of the new work after the entire filling in of the gap. The straightening, as here detailed, was successful, and the shaft now stands perpendicular. CHEMICAL WORKS, PITCHCOMBE, GLOUCESTERSHIRE. Straightening Chimney. The octagonal brick shaft at Messrs. Matthews & Sons' Works, as above, built 1862, and 132' high, gradually settled from its upright position until in 1875 it was found to be 3' 10" at top from the perpendicular. Mr. H. J. Taylor, of Nailsworth, assisted by three workmen, undertook to straighten the shaft, by means of cutting out one course of bricks on the five sides opposite to the inclination, inserting a thinner course in its place, and letting the stack Straightening Shafts. 127 regain its upright position by the action of gravitation. A plat- form was erected about 40' from the base, and the walls, which at this height were 2' in thickness, cut through by means of hammers and chisels. As the bricks were removed a thinner course was substituted, and the space above filled with iron wedges. This work lasted three weeks, the weather being most unfavourable. The chimney stood the operation well. When everything was in readiness the wedges were withdrawn, and the stack settled to within an inch or two of the perpendicular. It had been calculated that J" would bring the stack back 7" at top, so that the difference in the thicknesses of the courses had to be if". The cost of a new shaft was estimated at ^800, and the old one was straightened at about one-tenth this amount, and is still working satisfactorily. FALL OF SHAFTS. STRAIGHTENING AND FALL OF A CHIMNEY. Oldham. A large shaft 165' high, 16' diameter at base and 7' 6" diameter at top, was, in 1873, constructed at the new works of Messrs. Abraham Stott & Son, Osborn Mills, Feather Stall Road, Oldham. It was found necessary to straighten the pile, which leaned considerably over to one side. The owners, there- fore, entered into a contract with two brothers named Gradwell, of Newton Heath, to " saw" the chimney. Mr. Stott found that the men were taking out a whole course of bricks, at a third of the height of the shaft, and temporarily supplying its place with a series of wedges of wood and iron, instead of "sawing" the mortar out as arranged. The owner at once remonstrated with one of the men, but he declared the plan was safe, and took Mr. Stott to some rising ground adjacent, to observe the safety, when, as if in ridicule of his assertion, the chimney toppled over, except about 30' at the base. The poor fellow on the scaffold was buried in the fallen bricks. Adjacent to the shaft was the boiler house, a large new building, which was completely wrecked, a portion of the stalk falling upon it. At the inquest it was deposed that the shaft was built on sound principles, but in a faulty manner. The material was inferior, the bricks being soft and the mortar improperly mixed, consisting too largely of sand. 128 Tall Chimney Construction. TAKING DOWN AND FALL OF A CHIMNEY. Glasgow. A chimney nearly 100' high in the yard of a railway wagon builder at Glasgow, fell on January loth, 1870, killing two men. The stalk had been deemed insecure, and the men killed were employed with two others in taking down 20' from the top. Cross stays were erected inside the shaft, by means of which the men ascended to the top, where they removed the bricks, and dropped them inside the chimney. An aperture was made in the base 5' high by 3' wide, through which the two men at foot of shaft removed the fallen bricks. While they were so engaged the stalk suddenly gave way at the base, killing the two men at top ; the men at the bottom, however, escaped without injury. The accident was supposed to have been occasioned by the aperture weakening the base. HEIGHTENING AND FALL OF A CHIMNEY. Bury. On January 23rd, 1884, a chimney at Messrs. Allen and Parker's Eaton Vale bleachworks, near Bury, fell, killing three women and wrecking the building. The shaft was i O5'high, 7' 2" at base, 4' inside and 9" brickwork at top. The chimney was originally 90' high and was partly pulled down, rebuilt, raised and the batter lessened in June, 1870, by Messrs. Chris. Hardman & Sons, to increase the draught. In December, 1882, Mr. Robert Williams, of Elton, straightened the shaft by taking out a course of bricks from one side and replacing it with a thinner one ; he also put five wrought iron ties round the shaft, the uppermost one being above the cornice and stonework, there being a fissure in the blocking at top, part of which was nearly hanging off. The work was done in frosty weather. The crack was filled up with mastic and oil. Mr. James Maxwell, an architect, who examined on behalf of the Coroner, stated at the inquest that the base was defective, not only in its area but in the strength of the walls and the construction of same. The walls were built of 9" brickwork and 9" stonework outside. Little attempt had been made to obtain a proper bond. The increased height, he considered, to be the primary cause of the accident. The chimney was observed, at the time of accident, to be caught by a gust of w r ind that caused it to vibrate about a foot, and a second gust following brought down the stalk. It Fall of Shafts. 12Q appeared to break about 30' from the top. It fell in the direction to which it had previously inclined. A new shaft was to have been commenced on the day of accident. VIOLENT GALE, 1873, AND FALL OF CHIMNEYS. Sheffield. A square chimney, 1 1 6' high above ground, in Trippet Lane, Sheffield, belonging to Mr. W. Reynolds, fell during a severe gale on December i6th, 1873, killing 10 persons and injuring five. The chimney in its fall demolished a four- storey building adjoining. The chimney had often been observed to sway when the wind was high, and on the morning of the accident a number of people w r ere watching the oscillations, but the workpeople took no notice of it. The top was ornamental and made of terra cotta ; the cornice was hollow, so as to be as light as possible ; there was also a balustrade on the top. Mr. T. H. Jenkinson, an architect, gave evidence at the inquest that after the chimney had been erected exaggerated reports were circulated as to its rocking, and he made an examination during a severe gale and found the oscillation amounted to 2" each way. The attention of the Town Council had, he believed, been called to the chimney a few years ago. The chimney tapered about i' from the base to the top. Mr. W. Reynolds, builder, who also owned the shaft, said he was responsible for the erection ; nothing could have been put together better. It was built on the solid rock 4' below ground, and was 1 1 6' high from ground line. A quarter of an hour before the chimney fell he observed it oscillating more than it usually had done. The chimney broke 50' above the base. When the complaints were made to him soon after the completion he greatly strengthened the base, and thereby prevented much oscillation. The outside was composed of the best pressed bricks. The shaft was constructed in 1858 and cost ^300. Eight workshops were destroyed, and considerable damage done to the 20 h.p. engine by the fall. The damage to property, irrespective of a large stock of cutlery, in process of manufacture, was estimated at ,3,500. At the inquest the jurors expressed their opinion that the shaft was too high for the width of the base. The gale causing this disaster was an exceptionally severe one, and also caused the demolition of the following shafts in the neighbourhood, viz. : 130 Tall Chimney Construction. Portobello. Messrs. Chris. Johnson & Co., cutlery manufac- turers, Western Works, two chimney stacks blown down. No injury except to buildings. Wicker. Mr. Freckingham, Willey Street, engine chimney to the mortar mills blown down, falling through mortar mill roof. Spital Hill. Mr. J. Blyde, Hallcar Works, chimney stack fell, completely smashing roof. Bolsover Street. Mr. J. Dodworth, shaft to engine blown down. Furnace Hill. Messrs. Longden & Co., Phoenix Foundry, shaft 60' high blown down. Watery Lane. Messrs. W. Guest & Sons, Neptune Works, shaft blown down, demolishing a new cutlery shop and damaging house adjoining. Milton Street. Messrs. Matthewman & Sons, Milton Works, large brick chimney fell, considerably damaging the works. Savtlle Street. Messrs. Thos. Firth & Sons, Norfolk Works, shaft blown down, injuring three workmen and causing great destruction of machinery and buildings. The chimney was 120' high with i' 6" walls, and snapped about the middle. The fall- ing bricks broke the steam pipes from the boilers, and the steam severely scalded one of the men ; he was also crushed about the legs and body. Damage to buildings and machinery was estimated at ,1,000. BLOWING-DOWN SHAFTS. BLOWING-DOWN CHIMNEY. Dublin. On April loth, 1884, an attempt was made by the Royal Engineers to blow down a conical shaft built 1820, at the works of the Glass Bottle Company, North Lotts, Dublin, in the occupation of Mr. W. Campbell. In compliance with a requisition sent to the military authorities trained men were brought from the Curragh, and a dynamo-battery sent from Chatham to fire the charges. The work was under the superintendence of an officer of the Royal Engineers. The shaft was a truncated cone 95' in height and 64' diameter at base, with walls 4^' thick, tapering to ij' at top, and the weight was roughly estimated at Blowing-down Shafts. 131 2,500 tons. The shaft rested upon twelve piers or pillars of brickwork; in each of these a charge of cannon powder weighing 2J-lbs. was placed, closely "tamped up" and connected with a double electric wire attached to a low-pressure dynamo-machine, so as to fire the charges simultaneously. The machine was some 150 yards distant, on rising ground. At noon the charges were fired and a dozen little puffs of smoke became visible, there being little or no concussion, and with the exception that on the north and south sides of the shaft portions of brickwork slid slowly to the ground, the chimney stood as erect as before. A second attempt was made with 2O-lbs. of gunpowder, which was placed under one of the smaller arched openings on a beam that traversed it, and was closely packed with sand bags. The wires were connected afresh and the charge was exploded, but with no result beyond destroying the sand bags. At the suggestion of a bystander a chain was attached round one of the brick piers and the end fastened to the axle of a dray drawn by a couple of horses, but these failed to secure the desired effect and the idea was abandoned. An engine of the Great Southern and Western Railway, a branch of which adjoined the works, was next called into requisition. A chain was attached from the engine round a beam that spanned an opening in the base, the brickwork near to which looked shaky, the only result being that the beam broke. The chain was next passed round one of the brick supports and this time the draw bar of the engine gave way. The chain, however, was next attached to the rear of the engine and this time the chain broke. A 3" diameter hawser was then attached and the engine started, but the hawser, imperfectly fastened, dropped off. The men were again approaching the stubborn mass when there occurred a rumbling sound and a cloud of dust, and the immense shaft collapsed, fortunately before the men had reached the chimney. Warrington, Lancashire. About nine years ago the tall circular brick shaft at Messrs. Muspratt's Chemical Works, Warrington, 406' high, 46' diameter at base and 1 7' diameter at top, was blown down by gunpowder, the works having been moved to another locality and the chimney therefore being in disuse. Mr. Stephen Court, engineer and architect to the St. Helen's Canal and Railway Company, superintended the demoli- tion. A number of holes were delved round the base and fourteen charges of gunpowder inserted. The train was fired at 2.30 p.m. Nine charges exploded without any apparent damage being done to the stability of the shaft, but the report of the tenth had no sooner been heard than the chimney was rent from top to bottom and the huge mass gradually disintegrated from the base upwards. The whole of the stalk fell nearly within the circumference of its own base. No accident occurred. 132 Tall Chimney Construction. MOVING SHAFTS. MOVING A CHIMNEY. Cabot Company's Cotton Mill, Brunswick, Maine, U.S.A. A shaft at the above works was moved 20' in May, 1872, to allow of the enlargement of the mill. The shaft was 78' high, f 9" square at base, 5' square at top, contained 40,000 bricks, and weighed about 100 tons. The work was accomplished by moving the chimney on planed and greased planks by means of two screw jacks. The flues were re- connected, and the fires started within 8J hours from the commencement. The removal was planned and executed by Mr. Benjamin Greenes. CL 1MB ING CHIMNE YS , TALL CHIMNEY CLIMBING. Messrs. Sanderson & Co., of Huddersfield, have an ingenious method of ascending to the tops of tall chimneys for purposes of examination and repair. It consists in pushing length after length of short segments of a ladder, as it were telescopically, up against the perpendicular face of the shaft, and climbing simultaneously upon the lengthening out ladder. A number of ladders of 15' length are in the first instance prepared, which are identical with each other in detail and form, and which are so fashioned that the bottom of any one ladder can be dropped into sockets provided at the top of any of the rest. The sides of each segment are pivots at the bottom and sockets at the top. There are also standards or pegs about 8" long projecting out from one face of each segment, which serve the purpose of keeping it off the brickwork when it is fixed and by this means providing a secure foothold and handhold. The first step in the erection of the ladder consists in placing one of the sections standing perpendicularly upon the ground against the bottom of the chimney. A workman then drives an iron dog or holdfast firmly into the brickwork i' up from the bottom of the ladder and i' down from its top. These holdfasts are of a hooked form, so that they can each be made to clamp one of the rungs of the ladder when they are driven home upon it into the brickwork. The segment of the ladder is firmly Climbing Chimneys. 133 attached to the shaft of the chimney when this has been accom- plished. When one section of the ladder has been attached in this way a free ladder is sloped against it and the climber then ascends upon this until he can reach a foot above the top of the fixed segment. He there drives in a holdfast and attaches to it a pulley and block, so that one end of the rope reeved into the pulley can be brought half down a second loose section of the ladder, placed perpendicularly and side by side with the first. The rope is there fastened at midway height, and by means of the block the second section of the ladder is hauled up by men standing upon the ground until it projects half-ladder height above the section No. i . In that position it is temporarily lashed to the fixed section, rung to rung, so that the climber can mount to its top and drive a holdfast into the brickwork i' above its upper extremity. He then shifts the pulley and block to this upper holdfast and descends to the ground. Section 2, still attached to the rope at its middle part, is then hoisted up to its full height above section i. The climber, following its ascent, next inserts the pivots of its sides into the sockets at the top of section No. i, mounts upon its steps as, still held by the pulley, it leans against the chimney, drives home two hooked holdfasts, clamping its rungs to the chimney, near the bottom and near the top ; and this having been done the second section remains fixed in continuation of the first, and the ladder attached to the brick- work has thus grown from 15' to 30' in height. The climber is then able to mount to its top, 30' up the chimney, and extending his arm about \ higher upon the brickwork, drives in there the holdfast which becomes the point d'appui for the hauling up a third section of the ladder, first half its length and then full height above the second segment, so that it can be in its turn pivoted into the sockets. The third section, in doing this, is handled in every essential particular like the first, pulled half- ladder high, temporarily lashed to the topmost rungs of the fixed ladder, then lifted to its full height, pivoted into the sockets of the fixed ladder there and clamped firmly to the brickwork, and the fixed ladder has grown to a length of 45', by the junction of three segments of 15' each. This process is afterwards repeated with other sections of the ladder again and again, half lengths at a time, until a perpendicular path has been laid from the bottom to the top of the chimney. A chimney 255' high, it will be observed, requires seventeen sections of the ladder to reach to its top. The essential points in this ingenious process are: (i) The temporary lashing of each section of the ladder when it is half way up, so that the climber can get safely to the top, as it is held still attached to the pulley, and fix a fresh block above its upper 134 Tall Chimney Construction. extremity for the accomplishment of the second half of the hoist ; (2) the joining of the sections by appropriate sockets as each one is placed in position upon the one beneath ; and (3) the fixing of each section, when it is once lifted into its place, by the holdfasts driven into the brickwork of the chimney. The ladder virtually creeps up to the top of the chimney, joint above joint. The process is so easily performed by practised hands that the highest chimneys are scaled in brief intervals of time. The chimney at the Abbey Mills Pumping Station, near Stratford, 230' high, was laddered its entire height in three hours and a half by this method. VENTILATING SHAFTS. VENTILATION OF SEWERS BY MEANS OF TALL CHIMNEY SHAFTS. This means of ventilation has been used, where permission could be obtained from the owners of shafts, at CARLISLE. COVENTRY. BURTON-ON-TRENT. BlRKENHEAD. BLACKBURN. BOLTON-CUM-LINACRE. BOLTON. BURSLEM. HALIFAX. HYDE. NEWCASTLE. ROTHERHAM. SUNDERLAND. TYNEMOUTH. WHITER AVEN. WIDNESS. WOLVERH AMPTON . YORK. Carlisle. The Carlisle sewers, since their construction in 1855, have been ventilated by tall factory chimneys. This city was one of the first to take advantage of this help to sewer ventilation, and there are about thirty tall shafts connected with the sewers. Messrs. P. Dixon & Sons, of Shaddongate and West Tower Streets, were the first to allow the experiment to be made, on the understanding that if it was found to be injurious to the works the Carlisle authorities would cut off the connection ; this, however, was not required to be done. The sewers in the neighbourhood of their tall chimneys are well ventilated, the current of air passing through one of the ventilators connected to the Shaddongate shaft, 300' high, having a velocity of 50 miles per hour, the pressure of air at the base of the chimney being equal to a column of water i-p of an inch in height. From experiments made by Mr. H. U. McKie, City Surveyor, Carlisle, it was found the sewers were perceptibly ventilated for a radius of 400 yards, equal to an area of 502,656 square yards, or over 103 acres, and if the system of sewers and house drains Ventilating Shafts. 135 had been laid out and executed with a view of being ventilated by this shaft the surveyor had no doubt the radius could have been considerably extended. Leicester. No. 25 chimney shafts have been connected to the sewers of this town, and the Corporation are obtaining permission from manufacturers whenever they can to extend the system. Sunderland. No. 9 shafts are connected to the sewers here, and the surveyor says they are not a success. Great Yarmouth. No. 5 shafts, 50' high, have been specially built in connection with the main sewers to act as ventilators. Coventry. No. 15 shafts are here connected to the sewers of the town. York. No. 3 shafts are here utilized as ventilators. Hereford. No. i shaft only connected to sewers and the effect is quite local, the few ventilators adjoining invariably act as down cast shafts and the chimney as an up cast. Blackburn. In one case only is a chimney connected to aid the sewer ventilation. Bolton. A limited number of shafts have been utilized as sewer ventilators in this town, and with good results. Mr. E. Buckham, Borough Surveyor, Ipswich, does not share in the fear that damage is likely to arise from explosions caused by gas leaking into the sewers, and thence travelling to the chimneys ; he has not heard of such an accident and thinks the possibility of it occurring most remote. The fact that sewers are only affected by these shafts to a limited extent is, in his opinion, rather in favour of their use than otherwise, because where the exhaust is too powerful there is a probability of the traps of the house drains becoming unsealed. GENERAL. AN AWKWARD DILEMMA. In September, 1872, a chimney was being erected at Messrs. Smith's Works, Alyth, Scotland, and had reached a height of 100'. One evening, when the builder was about to descend, he discovered that the rope by which he was to reach the ground 136 Tall Chimney Construction. had fallen from its fastening. After various plans had been suggested and partially tried to rescue the isolated man, such as throwing up a stone with a cord attached and building a temporary wooden stair inside, the happy thought occurred to the builder of taking off one of his stockings and running down the yarn so as to reach the ground. The scheme succeeded. On the end of the woollen yarn reaching the base a small cord was attached. After this had been hauled to the top an ordinary rope was secured to the end of the cord and the rope drawn to the top, by which means the builder descended in safety to the great satisfaction of the hundreds of spectators who had assembled at the foot of the shaft. A NOVEL DINNER PARTY. Nottingham. At the Stanton Iron Works Company, near Nottingham, a chimney 190' high, 24' across the cap and 1 3' 9" across outlet, was erected in 1874. When the shaft was near its completion forty-seven of the workmen were entertained to a hot dinner at the top. Three young ladies also ascended to lay the cloth and wait upon the guests during their aerial banquet. Considerable interest was occasioned by so many people dining at such an elevation. The cap was cast at the Company's works and weighed 15 tons. The shaft contained 420,000 bricks. Farncornbe & Co., Printers, Lewes and Eastbourne. 00 TALL CHIMNEY CONSTRUCTION. fc.M &, F.J. Bancroft.) Plate 3 .f arncombe <& Co., Lith.. Lewes & Eastbourne. TALL CHIMNEY CONSTRUCTION.^ M &F. J.Bancroft) Plate 4 rarncombe & Co., LilH., Lewes A: Eastboiame. TALL CHIMNEY CONSTRUCTION (RM. & F. J.Bancroft. j Plate 5 Farnoom.be Jc C o.. Lith .Lewes; fc E.i:" TALL CHIMNEY CONSTRUCTION. (E.M.&.F. j.Bancroft.) Plate G 41 47 Fajocombe & Co, Litk-.Lew-es & Eastbourr. OF THf UNIVERSITY TALL CHIMNEY CONSTRUCTION. (R.M &F J Bancroft.) Plate 7. 48 ramcombe & Co., Lilt., Lewes ArZc.-- TALL CHIMNEY CONSTRUCTION. (R.M &F. J.Bancroft Plate 8. Faracombe <3r Cc',.Litk..Leirea ^Eastbourne. TALL CHIMNEY CONSTRUCTION (R.M. & r. J. 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