THE PLANNING AND CONSTRUCTION OF HIGH OFFICE-BUILDINGS. BY WILLIAM II. 15 IK KM IKK. -fnllti JMlnstratcb. S T ED 1 T I O N. FIRST THOUSAND. XK\V YORK : JOHN WILEY & SONS. LONDON: CHAPMAN \- HALL, LIMITED. 1 898. Copyright, 1898, BV WILLIAM H. BIRKM1RE. -)BKRT DRUM \IOND. F.LFCTI Ol VPER AND VR1NTPR. NKW YORK. uonvj MN PREFACE. Tins volume is presented to architects, engineers, and builders as supplementary to the author's work on " Skeleton Construction in Buildings," published in April, 1894. While the latter was written during the period of the change in building-construction methods, this is the result of his practical experience since that time in the planning, designing, and construction of high office-buildings, in which these structures have attained their present development. A number of articles on this subject, published in Ar- chitecture and Building, were so favorably received that he has been induced to edit this work. WILLIAM H. BIRKMIKE. NEW YORK, 1 898. TABLE OF CONTENTS. CHAPTER I. REPRESENTATIVE HIGH OI-F1CE-KCILDINGS AND THEIR DEVELOPMENT. PACE Introduction I New York's Representative High Office-buildings 2 Chicago's 7 Cause of the Modern Office-building Development 7 Elevators, Steel and Iron , solve the Problem S High Office-buildings Artistically Considered ... 13 A Limit to the Press Discussion against High Huildings . . . 19 Danger from Fire in High Buildings 31 The Rapid Erection of High Buildings 39 Rapid Erection of the Manhattan Life Building, New York 40 " " " Fisher Building, Chicago, 111 46 " " " Reliance " " " 51 The Progress of Erection of a High Office-building described 52 CHAPTER II. //, OOR-PI. A VNING. Floor-planning 66 Well-lighted Rooms 66 A Maximum of Rentable Space. 66 Schiller Theatre Office-floor Plan 63 American Tract Society Building Floor-plan 70 National Bank of Commerce Building Floor-plan 71 St. Paul Building Floor-plan 71 Commercial Cable Building Floor-plan 72 Good Elevator Service and Toilet Arrangements 74 Lord's Court Building Floor-plan , 70 VI TABLE OF CONTENTS. CHAPTER III. CEXTRAL BANK KU1LDIXG, NEW YORK. FAGF Central Bank Building, New York Si " " " Style of Architecture Si 1 Office Arrangement 86 " " " Steel used in the Construction 86 CHAPTER IV. EXTERIOR WALLS. Exterior Walls. ... 98 Curtain-walls, New York Building Law 101 Chicago " 103 Boston 103 Dangers of Sky-scrapers 105 Exterior Walls of the Central Bank Building 1 1 1 " Decorated 114 CHAPTER V. I-'LOOR-COKSTRl'CTION AND I- 1 'REPROOF1 'XG. Floor-construction and Fire proofing 119 Live Loads on Floors 119 Dead " " " 121 ' Floor- weights in the Central Bank Building 121 " " Old Colony Building, Chicago, 111 122 " " Marshal- Field " " " 123 Typical Floor-plan, Central Bank Building 12-; Fireproofing Floors 126 Various Fire-proof Floor Methods in Floor-construction 130 The Columbian Floor-arch 131 Fire-test 133 The Monnier System 13; !-"ire-test of the Boyd- Wilson Floor-arch i^(> Details of the Columbian System described 137 Dead Load of the " per Square Foot 138 The Roebling Floor arch 138 System, Ceiling 138 " Floor-system, Weight 139 Fire and Water Test . 139 " Weight-test 14' 1 1 ol low- tile Arches 142 Method of Setting 143 TABLE OF CONTENTS. Vli Hollow-tile Arches, Tests of Side and End Construction .......... ...... 143 " Description of Arches Tested ........................ 143 " Still-load Test ..................................... 144 Dropping Test .................................... 145 Fire and Water Test .............................. 145 Continuous Fire- tests ............................ 146 1 ' the Lee Tension-rod .............................. 141) Process of-construction of the Lee Arch .............................. 150 Tests of the Lee Tension-rod System ........ ........................ 151 The Fawcett Floor-construction ..................................... 1=3 Tests ................................. 154 The Rapp Floor-construction ...................................... 1^4 Tests ....................... ........... 155 The Metropolitan Floor-arch System ..... ............................ 155 Fire and Water Tests ............ i 56 The Acme Floor-arch ............................................. 1 = 7 The Multiplex. Steel Plate Floor-arch System ........................ 15$ The Practical Value of the Different Systems in Buildings and Tests by the Writer .............................................. ......... i 59 Partitions ........... .......... ................................... jt>i Fire-proof Building Construction in the Pittsburgh Fire, May 3, 1807 101 Effects of the Fire .................................................. 166 Progress and Intensity of the Fire ...................................... i 70 Estimate of the Salvage ................... ............................ 170 The Home Office-building Fire ...................................... 1 73 The Methodist Book-building Fire .................................. i 74 The Engineering A T eu>s' Review of the Pittsburgh Fire . . ................ 178 A Lesson to be Learned by the Pittsburgh Fire ................. ........ i S i CHAPTER VI. COLUMNS. Columns ............................................................ iSS Arrangement of Columns and Floor-plan .............................. iSs Skeleton Columns separated from Outside Walls ........................ i vj Cast iron Columns ................................................... i^r Steel Columns ..................................................... ii>2 Fi reproofing Columns ............................................. i Cast-iron Pillar Formula, " " ......... ............. ... 201 Riveted Column Formula, Steel and Iron, Buffalo Building Law ......... jui vi 11 TABLE OF CONTENTS. PAGE Strength of Columns, Chicago Building Law ... 202 Cast-iron Column Formula, Chicago Building Law 202 Riveted " " " " " 202 Remarks upon the Different Column Formulae 203 Column Joints 205 Wind-bracing 205 Beams and Girders 206 Connections for Beams of Different Sizes 207 Beam Connections 209 CHAPTER VII. FOU.\'DA T1ONS. Foundations ...... ................................................... 210 upon Firm and Compressible Soil .... .................... 210 Rock ............................................... 210 Clay .............................................. 211 " Gravel and Sand ............... ................... 211 Silt, Mud, Soft Earth, and Quicksand. ..... ......... 211 Bearing Power of Soils ............................................... 211 " Table ......................................... 212- The New York Building Law Requirements upon Soil .................... 212 The Chicago " " " ................... 212 Foundations of the Central Bank Building . . ......................... 213 " Lord's Court Building upon Piles ....................... 214 The \ew York Building Law Requirement for Driving Piles ........ .... 214 Formula for determining the Working Load on Piles .................... 216 Table of the Bearing Power of Piles. The Engineering News Formula .... 216 Concrete Capping on Piles ............................................ 216 Shoring arid Sheath -piling, Lord's Court Building ....................... 217 Requirements, Central Bank Building ......... 217 Pneumatic Caissons ................ ................................ 2iS Caisson Detail ................................... .................... 219 I lydraulic Caissons ............................................. ..... 220 Foundations upon Steel Beams and Concrete ................... ....... 222 Manner of Setting Steel Beams in Concrete ..... ....................... 222 Method of Calculating the Strength of Grillage Beams ............ ...... 223 CHAPTER VIII. i in-: MA ( y/AVA'A 1 ) '-HA I.L. The Machinery-hall .............................. ................... 226 of the Central Bank Building described .............. 230 Boilers .............................................................. 230 TABLE OF CONTENTS. ix . . Engines 235 Dynamos _ Electric Lighting in the Central Bank Building . 2 ^g Switchboard of " " " ' 2 Telegraph and Telephone Systems, Central Bank Building 243 Elevators _ ,, ,. Hydraulic Elevators, Central Bank Building 245 Electric Elevators in Lord's Court Building .... 249 Air-cushions for Elevators 254 Steam-heating 255 The Heating of Tall Buildings by Exhaust Steam 255 The Webster Vacuum System to Steam- heating 260 Description of the Heating and Power Plant in the Central Bank Building 270 A System of Temperature Regulation in Office-buildings 274 Refrigerator Apparatus and System of Cooling Drinking-water 277 Elevator Calling-signals 279 CHAPTER IX. /'/,;/.l/7'/.V(; A XI) DKAIXAGE. Plumbing and Drainage 287 Plumbing Rules and Regulations of the New York Building Law 287 Materials and Workmanship according to the above Law 289 Plans of Plumbing to be Approved by the Building Superintendent 294 Soil and \Vaste Pipes, New York Building Law 298 Plumbing and Drainage in the Central Bank Building 309 CHAPTER X. MISCE1J.A NEOl 'S DE TA ILS. Miscellaneous Details 314 Stairways 314 Passenger-elevator Fronts and Cars 314 Freight-elevator Enclosures 317 Elevator Gratings 317 Elevator Pits 317 Cast-iron Mullions and Panels 317 Doors and Shutters 318 Bulkheads on Roofs 322 Hanging Ceilings in Boiler-room 322 False Furring 3-- Skylights and Sheet-metal Work 322 Terra-cotta Work for Skeleton Buildings. . . 325 Brick and Sione Work 32') X TABLE OF CONTENTS. TAGI! Specification Requirements for Front Granite-work 329 Plastering 330 Interior Marble-work 333 Interior Trim and Woodwork 334 Painting 337 Safety Window Appliances 343 Revolving Entrance-doors 344 Hardware 344 Roofing 345 LIST OF ILLUSTRATIONS. CHAPTER I. mi. PACK 1. Main Entrance-hall, Metropolitan Life Ins. Bids, New York. . .Frontispiece 2. Empire Building. New York 3 3. St. Paul " 5 4. Postal Telegraph and Home Life Insurance Building, New York 9 5. Bowling Green Building, New York :i 6. Gillender Building, " 15 7. Commercial Cable Building, . \- 8. American Surety " 21 9. Manhattan Life Insurance Building. New York 23 10. American Tract Society 27 1 1 . Ivins Syndicate ;? 12. Queen Insurance Company 33 13. National Bank of Commerce " 35 14. St. James Building. New York 37 i 5. Masonic Temple, Chicago, 111 41 \(i. Old Colony Building. Chicago, 111 . 43 17. Manhattan Life Building Steel Frame. 141!] Story, Broadway Front. 45 1 3. " New Street " . 40 K). " ' " " i6th " " " " . 47 20. " " Broadway " . j3 21. " Completed Stonework, New Street ' . 40 22. " Roofed in and Tower ready for Covering "o 23. Fislier Building, Chicago. Ill =3 24. " " Starting Columns. On 12. 1^05 55 25. " " " Second Part of Third-story Set. ;i> 20. " ' Seventh Part of Eighth-story Set " 27. " " Fourteenth-story Set ^ s 23. " " Roof on, Nov. 26, 1895 hi 29. Reliance (>2 30. " " Completed Steel Frame IIT, Xlt LIST OF ILLUSTRATIONS. CHAPTER II. FIG. PACK 31. Schiller Theatre Building, Chicago, 111., Typical Floor-plan. 67 32. " " Plan of Ninth Floor 69 33 American Tract Society Building, New York, Typical Floor-plan 70 34. National Bank of Commerce Building, New York, Typical Floor-plan. 72 35. St. Paul Building, New York, Typical Floor-plan 73 36. Commercial Cable Building, New York, Typical Floor-plan 75 37. Lord's Court " 79 CHAPTER III. 38. Central Bank Building, New York 83 3g. " showing Condition, Oct. 24, 1896 . . 8" 40. " " Progress of Work, Nov. 14, 1896 91 41. Typical Floor-plan. 93 CHAPTER IV 42. Section of Warehouse Walls, New York Building Law 99 43. " " Curtain " 100 44. New Curtain-wall Section recommended by Writer 102 4 = . Curtain-wall Sections. Chicago Building Law 104 46. Guaranty Building, Buffalo, N. Y. Example of the upper Outside Walls built before the lower Wails 107 47. Exterior Walls of the Central Bank Building 1 10 4-5. A Fifteen -story Curt am -wall Section i io 41;. Central Bank Building. Detail Second Story Window Spandrels 112 = o. " Details of Third-story Lintels and Cornice.... 11^ = i . Thirteenth-story Window Details 114 s2. " Details of a Main Cornice I I ; 53. " Terra-cotui Column, ijth and 141!! Stories. ... 117 CHAPTER V. ^4 Central Bank Building, Typical Beam-plan. ... 124 Detail of Floor-panels 12^ = f'i. Columbian Floor-arch Section 126 and suspended Ceiling 127 i -inch Ribbed Bar Section 129 E(). li-inch 129 60. '' 2-inch " " 131 t) i . Columbian Floor-arch, cA-inch Ribbed Mar Section i", i 62 Steel Stirrup Section i 32 63. Perforated Stirrup Section i ; , 64. " " 13(1 <>(). The Roebling Floor-arch and Ceiling 140 67. Section of Pioneer Arch used in I )en.\ er T< s; ; . 144 OS. " Lee End-method Arcli used in Denver Tests 141 Oc) ' Wiijht Arch used in I Jen ver Tests 14; 70. Lee End-construction Tile-arch , . . . 14- 71. End construction A Ijutment- tile 14* 72. Side-method Arch 141 73. Detail Section ot the Lee Ten si on- rod Tile -arch . . . I ^ ! 74. Weight Test " ' " " 152 75. The Fa wcett Floor-arch I ; ; 70. The Rap p Fire -proof Floor-construction 155 77. The Acme Method of Fl< lor-arch 1=7 77'/.The Multiplex Steel plate Floor-arch I ^ 7>. Sketch Map, showing Relative Location of Buildings binned in the Pittsburgh F;re Ku 7<). Third-floor Plan of llorne Store, showing Nature of Steei 1'r.mie ioj ^o. Home Store Hard-tile Floor-arcli Construction. . . . i 05 51. " " \'ie\v of Daniayed I nterinr of l-'irsi I-'loor 11,7 52. " " '' " " F.xterior 170 S^. ' 1'artitions 17-" ^4. Methodist Mook Muilding, Conciete Floor-arch C'onstruction 177 ?.. " " " \"ie\v of Damaged IiHerioi -0. Detail showing Steel C'oiumn Separated from the Wall it Si;t potts, St. Paul Building. New ^'ork it)*< >7. Cast Columns, Scjuaic and Circular Sections lui SS. " 1 Sections I y I S<). " Detail of loin ts i<>2 (jo. Steei C'oiumn Section, Annies and Plates i j ; \ (13. " " /-bars n>3 '-14. The Gray Column Sections i o? (15. " " ' Hracket Cornice lions. tc/ i|0. Detail of Su-el-coiumn |oim, as used in the Central Hank 2O'> ()7. Beam Connections, S-inch to id-inch I beams .'07 i)S. " 6-inrh t 12-inch I beams joS LIST OF ILLL'STKAl'lOXS. CHAPTER VII. I If;. I'AGE <)(_). Section of Foundation, Central Hank Building 213 100. " " Lord's Court " 215 101. " showing Manner of Excavating Pneumatic Caisson 219 102. Detail of a Steel Caisson 220 103. Transverse Section of Manhattan Life Foundation 221 104. Detail of Steel-beam Grillage Foundation 224 CHAPTER VIII. KK Machinery-hall Plan of the Central National Bank Building 230 106. Sectional View of a Water-tube Boiler for High Office-buildings 231 107. Section of Boiler used in the Central Bank Building 233 108. Direct-connected Engine and Generator 238 109. Vertical Arrangement of Electric Wiring System in the Central Bank Building 239 i 10. Diagram of Switchboard, Central Bank Building 241 ill. ' '' Telegraph and Telephone System, Central Bank Building 244 ii 2. Plat) of a Coupled Elevator-car, Central Bank Building 24'> 113. Hydraulic Elevator-shaft 248 i 14. Ash-hoist, Central Bank Building 2511 i 15. Hoisting-nut for an Electric Elevator- machine 2= r I 1 o. Double-deck Electric Elevator-machine 252 i i 7. Single-deck 253 i 18. Thermostatic Valves of the Webster System of Steam-heating 262 i 19. Other Valves of the same System 262 1 20. The Thermostatic Valves in Connection with Radiators 2(;3 121. Airangement in Boiler-room of the Webster System of Steam-heating 2(14 122 Interior View of the Webster Feed -heater 26(1 i 23. An Improved Steam -condenser on Roof 273 124. Thermostat for Temperature Regulation 27=; 125. Thermostatic Valve for Temperature Regulation 270 126. General Arrangement of a Sanitary Drinking-water System 278 127. Air-compressor as used for a Drinking-water System in High Office- buildings 280 128. Main Commutator Switch and Control Magnets for Elevator Calling- signal 281 129. Switch Mechanism on Top of Elevator for Calling-signals 282 130. Details of Commutators for Elevator Calling-signals 283 i"!. Diagram of Wiring Connections for Elevator Calling-signals 285 LIST OF ILLUSTKATIONS. XV CHAPTER IX. FIG - PACK 132. Wash-basin Connections ... 309 133. Diagram of Pipe Connections of Men's Toilet-room 309 134. Plan of Men's Toilet-room, Central Bank Building 311 135. Diagram of Water-supply, Central Bank Building 312 CHAPTER X. 136. Detail of Elevator Fronts, Central Bank Budding 315 137. Ornamental Panel-grille Elevator Front. Central Bank Building 319 138. Detail of Fire-doors 321 139. Ornamental Elevator-car, Central Bank Building 323 HO. Lord's Court " 327 141. Detail of Elevator Fronts, " " " 331 142. " " " Bank of Commerce Building 335 THE PLANNING AND CONSTRUCTION OF HIGH OFFICE-BUILDINGS. CHAPTER I. REPRESENTATIVE HIGH OFFICE-BUILDINGS AND THEIR DEVELOPMENT. INTRODUCTION. The closing years of the nineteenth century present to the inhabitants of the United States and to visiting foreigners a complete transformation, in our large cities, of building-construction methods. Laws have been enacted from time to time to keep pace with the rapid growth of these methods, but they are still inadequate and cover only in a general way the requirements of this modern and phenomenal growth. \Yhile but a few years ago the building profession had to concern itself merely with the simpler problems of construc- tion, such as the erection of buildings of five and eight stories and within 100 feet in height, it is now called upon to solve the more difficult ones involved in the building of enormous structures of fifteen to twenty-nine stories and 350 feet in heiefht. THE PLANNING AND CONSTRUCTION OF Less than five years ago the conclusion was reached that the sixteen-story building was the limit, but since that time we have had the twenty-story; and the most notable build- ing, for its size, now in course of construction is being erected in Park Row. Including the towers, it is to be twenty-nine stories high, covering an area of nearly 15,000 square feet, and in no part will it be less than twenty-five stories in height. The front, facing the Post-office, will be twenty-seven stories, the top cornice being 336 feet above the street-level. The two flanking towers will each contain two stories to be used as offices, the cornice of the towers being 355 feet above the street, and the top of the lantern 386 feet above the same level. The foundations extend 34 feet below the street-level, making the total height of the structure from the top of piles to the top of lanterns 420 feet, the total dead and live load being about 50,000 tons. Following are the heights of twenty-nine buildings re- cently constructed or in process of construction in Xew York : Ivins Syndicate Building 29 stories, 386 feet. .Manhattan Life Building IS " and tower. 345 " St. Paul Building 26 American Surety Building 21 Pulitxer Building i(> " American Tract Society Building.. 21 Empire Building 20 Commercial Cable Building 20 " Gil lender Building 19 " Standard Oil Building (remodelled) 19 Bank of Commerce Building 19 Home Life Insurance Building.... ifi Washington Building 13 \e\v York Life Building 12 S. L. Mitchell I->tate Building 15 Mutual Life Building 14 Manhattan Hotel id I'r-'dnce Exchange Building 9 " and tower, 225 Bowling Green Building io --4 Fie;. 2.- 1'HK KMTIKK Hi ILIUM;, Ni-.w YOKK. (Kimbaii \ 'I hompsoTi, An. lntfi t~. ' HIGH OFFICE-BUILDINGS. ^ New Netherlands Hotel 16 stories, 220 feet. Central Bank Building 15 " 219 " Hudson Building 16 " 218 " Lord's CourtBuilding 15 " 214 " Johnston Building 15 " 212 " Syndicate Building 15 " 207 " Continental Ins. Co. Building 14 " 215 " Postal Telegraph Building 13 " 192 " Havemeyer Building 14 " 192 " Mutual Reserve Building 13 " 184 " Silk Exchange Building 13 " 180 " CHICAGO'S RKPRESE.NTATIVE HIGH BUILDINGS OVER 180 FEET. Masonic Temple 20 stories, 273 feet. To apex of roof 300 " Auditorium, with tower 17 " 265 " Fisher Building 18 " and attic, 235 " Old Colony Building 17 '' 213 " Katahdin & Wachussetts Building. 17 " 203 ft. 6 in. Unity Building 17 " 210 feet. Marquette Building 16 " 207 " Monadnock Building 16 " 215 " Ashland Block 16 " 200 ft. 7 in. The New Great Northern Building. 16 " 200 feet. Manhattan Building 16 " 197 " Reliance Building 14 200 " Security Building 14 200 " Title and Trust Building 16 198 " Woman's Temple 13 " 197 " Champlain Building 15 169 " CAUSE or THE MODERN OFFICE-BUILDING DEVELOP- MENT. While the enormous appreciation in land values is mainly due to the concentration of vast commercial interests within restricted areas, at the same time it is certain that in regard to the relation of those values to the height of build- ings the effect has in some measure become the cause. This state of things in Xe\v York is largely brought about by its rapidly developing' and changing character. The island is so narrow and its trade centre so near one end. that the tendencv of each trade is not onlv to llock to one THE PLANNING AND CONSTRUCTION OF spot, but to crowd as near this centre as possible, thus mak- ing the price of land down-town simply tremendous. In order, therefore, to secure an adequate return on an investment in such land more floor-space must be obtained. The greatest increase, as was to have been expected, has taken place upon property which fronts on Broadway, or that lies within the banking district in the neighborhood of \Yali, Pine, and Xassau streets and Park Row. As instances of this may be mentioned that the lot upon which the Man- hattan Life Building stands was purchased for $157.02 per square foot; that Xo. 141 Broadway cost $181.12 per square foot; and that before they could even dig the foundations for the American Surety Building the syndicate had to pay for the site at the rate of from $176 to $282 per square foot. ELEVATORS, STEEL AND IRON, SOLVE THE PROBLEM. To place buildings of ordinary height upon such property would necessitate the charging of enormous rents to derive an income on the ground values. Owners were therefore compelled to erect tall buildings, give more room and get more rent: and the higher the building the less desirable the rooms became, for tenants would not mount stairs in buildings of over five stories. Then steam, hydraulic, and electric elevators were invented, and at once the problem was solved. Then again, with the timber construction, in case of fire it was impossible to avert the destruction which inevitably oc- curred, and heavy masonry walls were required to support the superstructure. It was therefore necessary that the tim- ber construction be replaced by fire-proof materials, and the heavy walls by steel and iron, to protect the building from fire and increase the area of rentable space. This method once adopted, it soon culminated in what is called '" Skeleton Constructed Buildings." FIG. 4. POSTAL TELEGRAPH HI.DG., N. Y. HOME LII-K INS. Co. Hi no.. N. Y. (Geo. Kdw. Harding & Gooch, Architects.) (N. I.e. Hum ,V Sons. Ar. hitcc:- 9 I'lIK BiMVIIM, (iKKI-.N Bill. DING, N K\V \<>KK. FIG. q. HIGH OFFICE-BUILDINGS. 13 ARTISTICALLY CONSIDERED. It is not easy to imaem^ * o the feelings of a New Yorker exiled for a period of ten or twelve years no more who is returning- to his native land by one of the ocean steamships. As he looks about from the deck of the vessel as it steams up the bay, the first glance that he obtains of the lower part of Manhattan Island will probably be, if he has not been fore- warned, the greatest surprise of his life. Indeed it is a beautiful sight. Looked at from any point in the upper bay south of the Battery there can hardly be a more beautiful city in the world than Xew York is at the present time. Where Broadway stretches away directly in front, as the centre of the picture, is there a more perfectly carried sky- line, a more harmonious blending of color, or a nobler ap- pearance of the useful and the beautiful combined than these buildings that reach from river to river ? \Yhen we come to details there is indeed much to criti- cise and not a little to condemn; but the details are unim- portant as compared with the whole, and we may safely affirm that there is no problem of greater difficulty presented to the architects of the nineteenth century than the artistic designing of these buildings. The designing of such lofty structures is no doubt a purely resthetical matter, but should be governed by practi- cal considerations. When architects design a commercial building that is a positive ornament to the city and that is really picturesque in outline and effect, so that we may imagine an artist de- signed it. to paint it as a whole, we should be grateful. It is not the purpose to enter into the question of this modern use of styles, but to confine the subject to the plan- nine: and construction of such buildings. 14 THE PLANNING AND CONSTRUCTION OF This modern construction hampers, to a great extent, the free expression of artistic ideas, and we leave this introduc- tion quoting" the remarks from an able writer of one of the leading magazines : " Certain critics, and very thoughtful ones, have ad- vanced the theory that the true prototype of the tall office- building is the classical column, consisting of base, shaft, and capital. " Other theorizers, assuming a mystical symbolism as a guide, quote the many trinities in nature and in art, and the beauty and conclusiveness of such trinity and unity, the day subdivided into morning, noon, and night. " Others, of purely intellectual temperament, hold that such a design should be in the nature of a logical statement; it should have a beginning, a middle, and an ending, each clearly defined. " ( )thers. seeking their examples and justification in the vegetable kingdom, urge that such a design shall, above all things, be organic. They quote the suitable flower, with its bunch of leaves at the earth and its long graceful stem carry- ing the gorgeous single flower. ( )thers still, more susceptible to the power of a unit than the grace of a trinity, say that such a design should be struck out at a blow, as though by a blacksmith or by a might}' Jove, or should be thought-born, as was Minerva, full-grown." All these critics and theorists agree, however, positively, unequivocally, in this that the tall office-buildings should not, must not. be made a field for the displav of architectural knowledge in the encyclopaedic sense: that too much learn- ing is fully as dangerous, obnoxious, as too little learning: that miscellany is abhorrent to their sense: that the sixteen- story office-building must not consist of sixteen separate. Hi I ifiil FK;. (). GIM.KNPKK Mrn.DiNt;, \K\V VUKK. (Bciy & Clark, Aicliiuxts.) ?,'"Ij_ l^^l^^irrfi T iiTrft *? : _*,i FK;. 7. COMMKKCIAI C'Aiii.i: Hi ii. DIM;, Ni-.u V"KK. ((it-o. ICiiw. Harding cV (loin h. .A tcii itfct>. > 17 HIGH OFFICE-BUILDINGS. 19 distinct, and unrelated buildings piled one on the other until the top of the building is reached. While the artistic side of the office-building is receiving- considerable attention, it must not be forgotten that it is a business venture, in which the rents shall return a net profit on the investment. It is in many cases an exceedingly costly structure, and \ve should confine its designing to an attractive exterior and a well-planned interior that will attract tenants and excite favorable criticism. The prodigious growth in the number of these large office-buildings in the principal cities of this country is sim- ply phenomenal. They have become popular with in- vestors ; whether they pay or not the experienced owner and builder alone can tell. In a majority of examples. as those owned by great corporations, viz., the Manhattan Life Insurance Co., the Metropolitan Life Insurance Co., the New York Life Insurance Co.. and the American Surety Co., all of Xew York, being fitted up in palatial style, they are, without doubt, used as advertisements in displaying the wealth of their owners. A LIMIT TO THE PRKSS DISCUSSIONS AGAINST HIGH BUILDINGS. The movement in our cities against the further erection of tall buildings has become so decided, and the press criticisms so one-sided, that the author cannot help ([noting the following article on "Limit the 1 )iscussi<>n." from Architecture and HniliJiiii;, February. iSgj: " It has occurred to me that this discussion of the ' sky- scraper ' question has a ridiculous side ridiculous at least to the better informed. I presume this same thought has occurred to many architects, and it may be this ap- parent irresponsibility which has deterred some one from making serious answer to some of the many queer state- 2O 7 'HE PLANNING AND CONSTRUCTION OF ments that have appeared in print, and seem to be received with credulity by the press, and possibly the public. That a reasonable investigation and discussion of the question is proper, and that a reasonable limiting of the height of structures is a desired result, seems to be an accepted proposition ; but it occurs to me that to put forward weak and puerile, not to say utterly unfounded, statements does not add to the argument, but rather detracts in the minds of the thinking from the seriousness of the question. For example, a statement appeared recently in a local journal stating that a ' tenant in. the Tract Society Building was responsible for the assertion that the reliability of a timepiece was affected by the vibration of this building, and in a degree in propor- tion to the height, and that in fact on the top floor a clock had actually been known to stop.' This discussion went so far as actually to foretell the unhappy condition of affairs if it were necessary to abandon the use of pendulum-clocks and depend upon some other form of clock mechanism. Xow it happens to be the fact that in the office of D. H. Burnham. architect, of Chicago, a most careful and methodi- cal watch had been kept, for over eight years, of the struc- tures which have been built under his supervision, for this and any other contingency. I doubt if a severer test has ever been recorded than that of eighty-five miles an hour for five minutes at a time, which is on record in Mr. Burnham's office, and this was not perceptible within any of the struc- tures. " Mr. L. Stebbins, of Chicago, is responsible for several tests made when the wind was blowing over eighty miles an hour, in the Monadnock and in the Pontiac buildings, two of Chicago's tallest. This report shows the alarming move- ment or vibration of one quarter of one inch, and of seven sixteenths of one inch. I am at a loss to appreciate the mo- Fui. 8. A.MKKICAN SrKK.rv HIILDIM;, \K\V VOKK. (Bruce 1'ricc, Architect.) 9. MANHATTAN LIKK INSCKANCK Hi ( Kimtuiil & Thiimpson, Atvhuei HIGH OFFICE-BUILDINGS. 2$ live of such statements as that the swaying of the Tract Building in this city was one foot out of plumb-line. An- other story is of floating pontoons on the top story of a tall building on Union Square, and that certain heavy pieces of machinery were launched upon these pontoons, these pon- toons being elaborately chained and anchored to the walls, this all being done to prevent the catastrophe of the machin- ery being hurled bodily through the walls. It does not seem proper that this alarming tale should have been started upon its misleading journey, and really not credible that it should have been republished, at this writing, no less than five times. It must be admitted that the wind has considerably more vigor in Chicago and other Western cities than in this vicinity, and it must not be admitted that there may be su- perior features of construction through which vibration or other contingencies may have been overcome, and which are known and practised by our Chicago fellows and lost on this city. There is this view to be taken of these misstatements the architects of to-day have quite fully demonstrated to the world their ability to cope with every question in modern building construction; and it should not be passed without a protest that any modern practitioner would lend himself to the erection of a building in which uncertainty seemed to reign supreme. Another extract from a Doston paper reads ' A Fresh Danger ' (fresh danger is good) ' from High I'uild- ings." There are thirty-two hundred buildings in Xew York that are unsafe, the article goes on at length to say. and lays the blame upon the sky-scraper. 1 cannot but feel that a correction should have come from another source before this time, but, as it still stands unconnected, 1 will take the liberty to suggest that this is a misapplication which, for- getting the ridiculous side, would be outrageous. The 26 THE PLANNING AND CONSTRUCTION OF buildings referred to that is, about thirty-one hundred and ninety-nine of them are the ruins of a past age, like cen- tenarians that they are, tottering through their last days, no one, while yet they have strength to stand, seeming willing to offer a friendly push to their end. From another journal I read that ' these structures have so often proven danger- ous to life and limb.' ^ " I will risk at first blush the statement that in no other advance of modern times has life and limb been so remark- ably safe as to the occupants and patrons of a modern steel building. The climax is reached, however, in a cupping- glass tale appearing in a local journal with elaborate illustra- tions. The sublimity of ridiculousness is here, if ever, reached. An elaborate essay on sanitation or sanitary en- gineering might be required for the lay reader's protection against this dangerous discussion, but if by chance this should reach the eye of some nervous reader of that awful tale, it might be well to spend just ten minutes in an ex- amination of the toilet arrangements of any properly con- structed modern building, bearing in mind the basic prin- ciples of ventilation. Then before leaving such a building a glance at a modern basement or sub-basement is the only answer that need be made to the ' ground dampness.' In- these basements is the mechanical equipment of the building, machinery of the most delicate character, to which the least dampness would be demoralizing. Xo part of the building is more carefully protected from such danger. I will suggest that there might be some limit to these wild and effervescent stories, and rather should these questions be left to tlie con- sideration of those whose life study and work fit them for its * This item seems to refer to elevator accidents. We have had some, but we must consider that the seven thousand elevators of New York carry more than a million passengers daily. FIG. io. AMERICAN TRACT SOCIETY Mm. DIM;, \F.\V YUKK. (R. H. RnbciiMjn, Ar^ hitccl.i ., _ -, , , n bW tab h ~ bit- Lit- yy Fir.. II. IVINS SYNI'Ii'ATK HllI.lMNi;, X I- \V \'<>KK. HIGH OFFICE-BUILDINGS. 31 proper treatment the architects and their able co-workers, the specialists in engineering. No good can come of this wild and disconnected display of ignorance. ' There are really but two questions seriously demand- ing consideration the proper protection of the steel frame against elements of danger, decay and fire, and the obstruc- tion of the light from surrounding properties. " I trust that questions like the inadequateness of the sewer system, the congestion of travel on sidewalks, and proper supply of water in event of fire will be met by modern men of modern minds." DANGER FROM FIRE ix HIGH BUILDINGS. Architects and engineers should provide for the uses to which a build- ing is to be put up, and remove from it every possible danger from fire. They know from the beginning that there is nothing that will not undergo change of form through con- tact with heat, though the resistance to change is different in the various cases. Brick is one of the very best protect- ives against fire, and tire-proof buildings are made in Kurope by vaulting, but this is only possible in comparatively lo\v buildings. The requirements of a greater thickness of brick wall in proportion to the height of the buildings made it necessary that some other material should be found to carry the floors before our high buildings could be thought ot. But the fire-resisting qualities of brick, or the clay of which it is made, are shown not onlv by the degree of heat to which it is subjected in making, but also by its use in great furnaces. where intense heat is generated to melt metal. '1 he use of brick being for the reason stated impracticable, the architect selected iron for his structure: but as iron would be likely to warp and bend and lose its power of support under the heat that could be created in a burning building, he had to look around for a protective, and he found it in the kitchen- 32 THE PLANNING AND CONSTRUCTION OF stove. The principle that protects the inner sides of the cooking-range from the burning coal with which they are al- ways in contact is the same as that which is applied to the iron in buildings. Neither a kitchen-range nor a building could be constructed wholly of fire-brick, nor for practical purposes wholly of iron; but either may be made of iron, and made practical in use by the protection of fire-brick. This principle of construction and protection has been proven to be sound not only in the small degree furnished by the kitchen-range, but in the greater degree furnished by the burning building. One of the most striking examples of this fact is the fire that occurred several years ago in the \Yestern Union Building. This fire broke out in the battery- room, and was carried to the operating-room on the next floor. In the battery-room were 35,000 cups, each contain- ing an inch of sperm-oil, always in use, and handled by boys, who had in the course of time spilled a great deal of oil on the floor, so that it was thoroughly soaked, as were also the white-pine racks in which the cups were kept. Finer kindling could not be imagined than a room so prepared. From the battery-room a wire ran up through the floor to each of the many operating-tables in the room above, so that there were some hundreds of flues to convey the fire from the room below to that above. The ceiling of the upper room \vas covered by a network of wires insulated by a rubber cov- ering. A better combustion-chamber could not be devised. As may be imagined, the fire that raged in these rooms was a very fierce one. The beams in the floor between the t\vo rooms were protected on the top by a layer of concrete, the feet of the beams were not protected at all: but only a fe\v of these beams were deflected, and none showed signs of impor- tant weakness, while an unprotected iron gallery and stairway were twisted all out of shape. Fires have occurred in mod- Fi<;. 13. TIIK NATIONAL HANK v CD.MMKKCK HriLiuNc,, NK\V YORK. i I. B. Baker. Architect.) Fit;. 14. ST. JA.MKS Hi II.DI.M,, NK\V YORK. (Bruce Price, Architect.) 37 HIGH OFFICE-BUILDINGS. 39 ern fire-proof buildings, but have burnt themselves out with- out doing any more than destroying the furniture and trim and bringing down the plaster, leaving exposed but unhurt the fire-proof brick. All the material in an ordinary office cannot create enough heat to break through the fire-proof partitions or the ceilings. There are, of course, exceptions; but upon close inspection there will be found some inherent defect in the construction. THE RAPID ERECTION OF HIGH BUILDINGS. In this modern office-building era there is nothing more wonderful than the fact that we are able to accomplish now in a few months the erection and completion of structures which formerly took over a year. A ten-story building was, only a few years back, considered a fair year's work, but at the pres- ent time it can be completed and tenanted in six months. and a twenty-five-story building finished in twelve. This, of course, is taken from the time that the founda- tions are begun, the plans having been prepared by the archi- tect two or three months previous. The two great factors which enable us to accomplish so much in such a short time are undoubtedly the elevator and the skeleton system of construction. The elevator is the chief economical device which renders these lofty buildings also accessible. The skeleton steel frame is the main support, and it can be erected in all kinds of weather, and, as is often the case, two and sometimes three story columns are raised at once. and in a few days the stories are complete, ready for the floor- arches and brick walls. This system is not only a rapid one. but the lower por- tions of a building can be, if desired, practically completed before the upper parts. 4O THE PLANNING AND CONSTRUCTION OF When the walls are carried upon girders independently at each floor, it is possible to complete any story without reference to what is above or below, and, as usually happens, the lower floors are the last to be given their complete form. This question of speed in erection is most important. There being a large amount of capital invested, there should be but one season lost before a return is effected upon this investment. RAPID ERECTION OF THE MANHATTAN LIFE BUILDING, NEW YORK. Quoting from an article in the Engineering Magazine, Mr. Francis Kimball, the architect of the Man- hattan Life Insurance Building, states that " the building was completed in thirteen and two-thirds months, the time consumed being divided as follows: Foundations ready for the superstructure, five and two-thirds months; superstruc- ture, eight months. The roof, or eighteenth tier of beams, was readied in exactly three months from the time when the foundations were ready to which to set the first piece of steel composing the bolsters that support the cantilever system. ' 1 he time spent in preparing the foundations may seem, to those unfamiliar with the work, scarcely consistent with the progress afterward made; but the architects found that, in view of the unsatisfactory nature of the ground, composed largely of quicksand, the usual methods employed were in- adequate for the purpose of the foundation to sustain the great concentrated loads, and they thereupon decided to reach bed-rock, 57 feet below Broadway. The pneumatic process was introduced, such as is usually done in sinking bridge-piers to rock.'' The magnitude of the work may be better understood by reducing it to cubic yards of masonry. The substructure, which starts on bed-rock and continues up to the level of the FIG. 15. MAMJNIC TKMIT,K, CIUCAC.O, ILL. I Burnlum & Root, Architects.) FIG. 1 6. Oi.n COI.ONY HIILDIM,, CHICAGO ILL, (Holabird & Roche. Aiclmecis.) HIGH OFFICE-B UILDINGS. 45 cellar floor, consists of fifteen piers, varying in size from 9 feet in diameter to 21 feet 6 inches by 25 feet square. The caissons, made of steel, correspond in size to the piers the\" sustain, and are i i feet in height. These caissons are filled with concrete, and contain alto- Fir,. 17. BROADWAY FRONT, XOVF.MHKK iS. MANHATTAN' I. MI: l!i ILIUM;. gether 12(10 cubic yards. The number of bricks used in the piers amount to 1,500.000. The superstructure, when once started, proceeded rap- idly, the rate of progress being shown by the illustrations given. 4 6 THE PLANNING AND CONSTRUCTION OF The first six stories of the iron frame were completed on October 17, 1893; one month later, November 18, the fifth- story stonework and fourteenth-story steel frame were com- pleted. (See the illustration. Fig. 17, which shows the Broadway front, and Fig. 18, the New Street front.) FIG. iS. NEW STREET FRONT, NOVEMBER 18. MANHATTAN LIFE Brn.nixG. On January 12 the work was completed, as shown by Figs. 19 and 20, and the building was practically completed in March, as shown by the illustrations. Figs. 21 and 22, the tower still remaining to be covered with copper. RAPID ERECTION OF THE FISHER BUILDING, CHICAGO. The Fisher Building of Chicago (Fig. 23) is an example of HIGH OFFICE-B UILDINGS 47 rapid workmanship. It is practically a building without' walls. The total number of bricks used in the whole was only 225,000, and these were employed in backing up and strengthening parts of the terra-cotta of the front. Only Flii. I<> \K\vSTRKKTFRONT, JANUARY 12. MANHATTAN LlM-: H two bricklayers were employed at any lime on thi> pan n the work. The Fisher lUiildiug was designed by I). 11. lluniham tS: Co.. Architects, and is situated on the shallow block' between Dearborn Street and Plymouth Place, fronting on both of these, and having its south front on \ an l>ureu Street. 4 8 THE PLANNING AND CONSTRUCTION OF The front on Van Buren Street is 70 ieet 6 inches, and the fronts on Dearborn Street and Plymouth Place are 100 feet each. The height is 235 feet from the sidewalk to the top of cornice. \Yithin these dimensions it contains eighteen stories and an attic. Its cubic area is 1,960,000 feet from the Fit;. 20. HROAIAVAY FRONT, JANUARY 12. MANHATTAN LIFE Bi II.IHNC. foundation, and it cost about $575,000, or very nearly 30 cents per cubic foot. The illustration. Fig. 24, represents the starting of the columns, Oct. 12, 1895: Fig. 25, the second and part of the third-story set; Fig. 26, taken Oct. 26, the seventh and part HIGH OFFICE-BUILDINGS. 49 of the eighth story set; Fig. 27, the fourteenth-story set, and the front started at fourth story and the floor-arches in on the sixth story. Fig. 28 represents the roof on and the fronts up to the twelfth story. This view was taken Xov. 26. To make the above clear, from the day of signing the FIG. 2i. NEW STREET FRONT, MARCH 2. MANHATTAN LI?E Bni.niNG. Stonework Completed. contract, June 27. 1895. to the day the llrsi tenant moved in. April 23, i8, was nearly ten months; but the actual work- ing time, from the time the superstructure was started until the final completion of the building, was only a tritle over six 50 THE PLANNING AND CONSTRUCTION OF months and a half. The following table gives the exact dates : 1895. June 27. Contract signed. July 3. Ground broken. ^ IBuS' .-\ugust. Commenced driving piles and started founda- tion over piles and concrete. HIGH OFFICE-BUILDIXGS. 51 September. Piling-, concrete, and steel foundation com- pleted. Oct. 3. First piece of vertical steel started. Oct. 12. First floor-beams set. Xov. 12. Highest piece of steel on building set. Xov. 25. Roof set and under water-proof cover. Dec. 10. All hollow-tile floor-arches set. Dec. 12. Contract let for interior marble-work. Dec. 25. Contract let for glass mosaic ceilings. 1896. Jan. 2. Complete details drawings for interior marble- work received. April 23. First tenant moved in. May i. Marble and mosaic work completed and build- ing readv for tenants. An examination of the above will show that there were some delays in the building. The first was due to the failure to receive structural steel in September, 1895. But it shows that the whole of the steel skeleton above the first iloor was set between Oct. 12 and Xov. 12. Xineteen stories, includ- ing the attic, were set in twenty-six davs, live davs being lost between ( Vt. 12 and Xov. 12 by bad weather, when men could not work in the open air. During the whole lime ot build- ing no overtime or night-work was done. I he entire work was accomplished by careful attention to detail-- and intel- ligent division of labor. RAPID KRFCTIOX OF TIIK RKLIAXCF BriLnixc. CHI- CAGO. The Reliance Building, containing fourteen stories, was another building of Chicago rapidly erected, the s'.eel frame beinir constructed in about three weeks. See the two $2 THE PLANNING AND CONSTRUCTION OF illustrations, Fig. 29 representing the skeleton and Fig. 30 the completed building, in which enamelled terra-cotta was used, covering the entire fronts. THE PROGRESS OF ERECTION OF A HIGH OFFICE-BUILD- IXG DESCRIBED. There is probably no more interesting subject to follow than that of the different trades throughout the erection of these buildings. After the property has been bought and plans under way. a contract is made covering the tearing down of the old buildings to the curb level or to the old cellar bottom and clearing away all rubbish so that the excavator can begin his work for the foundation trenches of the side walls and the piers ; at the same time a contract is made covering any shoring or sheath-piling which may be necessary in treacher- ous soils. When the building is carried below the adjoining property, spur-bracing and underpinning are necessary. The street is to be braced and sheath-piled, and bridges for the sidewalks (about 8 or 10 feet wide). 3 feet above the street-level, are to be furnished. All the subways, hydrants, lamp-posts, gas-mains, and property belonging to the city or private corporations are to be taken care of, and the owner is to be protected from any suit or damage to any person or persons during the progress of the shoring or sheath-piling work. If the soil is of such a nature that the foundation must be of piles, they will be 8 to 12 inches in diameter at the larger and about 5 inches at the smaller end. the length, being determined by the low-water mark and bearing-power of the soil through which they are driven. They are usually placed 2 feet to 2 feet 6 inches centres and cut off i foot be- low the low-water level, and the heads covered with concrete about 18 inches below the top and levelled off with the same material to anv height desired. .Fi'i. 23. FISIIKK Hi "ii. DIM;, CHICAGO. ILL. (Burnham & Co.. Architects.) 54 THE PLANNING AND CONSTRUCTION OF If the soil is of sand, or sand and gravel, the trenches must be tilled with concrete for the foundations of the build- ing: and the foundations for the pumps and whatever is re- quired for elevators, boilers, etc., may be made at a later date. Various schemes of foundations have been built to sup- port these structures. Upon the foundation-beds the granite pier-stones are placed which support the building. All the base-stones are to be well bedded and to be perfectly level on the top sur- faces preparatory for receiving the brickwork, if any. and the column liases. These stones are usually 18 inches thick, and in correct proportion to the load to be supported. The rolling-mills having at least one half of the work of the building finished by the time the foundations and base- stones are all set. the steel frame is therefore started and pro- ceeds rapidly, at the rate of two or more stories in each week. and at the same time the finished front: stonework is under way: and after four or five stories of steel are set the brick masonry is started, which plan enables the frame-setter to keep in advance of the other trades. As far as possible this plan is pursued throughout. As it is customary for the iron-setter to rivet up all his column connections and do a great amount of bolting, every precaution should be taken to see that the bolt and rivet holes are filled up. as by crowding the masonry too close to this work many holes have been left without bolts or rivets. The arches which form the floors of the building are set and finished as fast as consistent with the progress of the steel frame, the walls being carried along at the same time, while the window-frames are all placed in their proper posi- tions and secured and bound in with masonrv. FK; 26. FISHER Brn.niNG, Seventh Part of FCiyhth Story Set. irteenth Storv Set. HIGH OFFICE-BUILDINGS. 59 As we approach the roof of the building with the steel frame and filling in the floors, the masonry is making great headway. The fronts, which are usually embellished with terra-cotta or fine stones, are following in great strides also toward the roof. The plumber has started at the basement with his line of waste and vent pipes, and the leaders are being set. so that when the roof is covered with concrete and waterproofing the water will be carried off. l~p to this time all the material for the building has been carried to the various floors with the ordinary hod-hoist, of which there may be three or four. After the roof is protected all the floor-arches are set, and the carpenter has laid out the door and window studs if of wood, and the iron contractor if of iron, so that the terra- cotta tile partitions are being set rapidly throughout the en- tire building. \Ve must not forget the fact that a temporary stairwav is to be put in the building for the use of the mechanics and laborers. This is made when the floors are filled up to the fourth storv. and is constructed of rough-dressed -prucc lum- ber, the stringers 3 by I _' inches, with cleats nailed to them for support of treads, the treads being 2 by 10 inch plank-. The rail is 2 by 3 inches and placed on each -ide 01 strings, with upright braces _' bv 3 niche-, spaced about 5 feel apart. The carpenters are also laving the ^ bv 4 inch '"ough spruce sleepers at the same lime a- the studding. I he-e sleepers are bevelled and set |S inches on centres, and are anchored to the top flange of the floor-beams with iron or wooden clamps. I'pon the sleepers a rough flooring ot tongued-and- grooved board- are secured. I he corridors and toilet- rooms have no sleepers or rough flooring; they are uvner- 60 THE PLANNING AND CONSTRUCTION OF ally furnished with mosaic or marble blocks set in cement, under which a form of concrete is laid. At this time in the process of the erection of the building the mechanics of the contractor who furnishes the architec- tural ironwork are putting up the stairways, elevator en- closure posts, the freight-elevator jambs, saddles, etc., and cast-iron mullions in courts. The plumber is netting his roughing for the wash-basins and toilet-rooms. The marble-contractor is setting the marble wainscoting in halls and toilet-rooms. The steam-contractor has his up-and-down pipes in place. The electrician has tubes laid throughout the building, but no wires drawn. The carpenter has his plaster grounds for the baseboard and chair-rail in place, and then the plasterer, with his mortar and trowels, takes possession and covers all this work with a white covering. The latter usually takes but a short time to go through the building, but he is almost the last con- tractor to leave the building, for the reason that there is al- ways a great amount of patching to be done, and work has to be changed here and there: some of the other contractors did not keep ahead of the plasterers or the mechanics did a little more racking to the partitions than they should have clone. \\ hen any one floor is finished by the plasterers the car- penter begins to set the trim. This work is usually all pre- pared at the planing-mill, with one coat of filler and white varnish, and sent to the building and immediately set in place, and the hardware put on as soon as consistent with the progress of the work. The finished flooring is set at the r-ame time. FIG. 28. FISIIEK B Fir,. 29. RKI.IANCK lirn DIM;, CIIICACO, ILL. i I), il. BiiinlKim >v Co.. Art huccts.i Fa;. 30. RELIANCK BCII.DIM;, Completed Steel Frame. 63 64 THE PLANNING AND CONSTRUCTION OF The painter here follows up the carpenter, the require- ments of his specifications being that he shall paint all wood and iron work on the exterior of the building, window trim and sash, all galvanized ironwork, interior ironwork not electroplated, interior pine woodwork; and all hard wood on the interior varnished in three or four coats, and the last coat rubbed down with pumice-stone and crude oil to a dead finish. The interior partition glass, gas, and electric fixtures, steam-radiators, plumbing fixtures, and elevator-cars at this time are all being finished, the building cleaned down and made ready for tenants. \Yhile the upper floors are being pushed along to com- pletion, the machinery hall in basement or cellar is having its heavy machinery for supplying steam for running ele- vators and heat for the building. The engines, with their direct-connected dynamos which supply light and power, if there are electric elevators, and the switchboard, with its endless variety of wires and meters, are all being put in place. Fire-pumps, with stand-pipes and hose rack and nozzles, are placed on each floor, and in addition to all the above the building is equipped with telephone and telegraph wires, so that at a box in the cellar any system can be attached to these wires without stringing any additional wire at any future time, the offices all having the wire supplied from these cables, which extend through the building. The speed with which such buildings are finished de- pends upon system. Every set of mechanics with their material must start in at the proper time, and, in addition to the day-work, it very frequently happens that a night gang of men will be required. The 7O THE PLANNING AND CONSTRUCTION OF ridor 7 feet 6 inches wide, and that in front or between ele- vators 8 feet. The long courts are 18 feet wide by 105 feet long. AMERICAN TRACT SOCIETY BUILDING FLOOR-PLAN. One of the mocst successful high buildings in Xew York for renting is the American Tract Society's, shown in plan, Fig. ;ASSAU STREET FK;. 33. AMERICAN TRACT SOCIKTV HriLniNG. Typical Floor-plan. (K. H. Robertson. Architect.) 33. There are twenty floors above the first, which are divided into thirty-six offices on each floor, ranging from <) feet wide by i i feet 6 inches long to 9 feet wide by 17 feet long. There are two open courts extending nearly north and south, the middle or larger court being 16 feet wide by 60 feet long and the smaller court / feet wide by 60 feet long. HIGH OFFICE-BUILDINGS. 71 Every office, toilet-room, and elevator-well has outside light, the elevators (five in number), toilet-rooms, and vent-shafts being placed in the least desirable part. The wing between the courts and that adjoining the elevator could be made into large offices if so desired by tenants requiring such an arrangement. The corridors are 5 feet wide and the circular space in front of elevators to stairs 1 1 feet wide. This arrangement of plan and courts is the only practical solution of the plot, unless the courts are extended east and west instead of north and south. The windows on the street fronts are not less than 5 feet in width, and those offices in courts have practically all windows, the larger pier.; being necessary on account of the columns which support the su- perstructure. NATIONAL BANK OF COMMERCE BUILDING FLOOR-PLAN. By comparing this plan (Fig. 34) with the one mentioned above we have a similar treatment of the plot. \Yhile the Tract Society Building stands upon the southeast corner of Nassau Street, this one is upon the northeast corner of the same street. The large court is made 24 feet wide by 48 feet long. The Clearing-house on the west side fortunately being a low and permanent building, another court was dispensed with. In addition to the offices shown upon this plan the larger offices could be again divided into reasonably smaller ones. This building contains one more elevator than the Tract Society Building and is three stories less in height, being but nineteen stories. ST. PAUL BUILDING. In the typical floor-plan (Fig. 35) we have a twenty-six-story building, in which the plot is of such a shape that the office unit is considerably larger than 72 7 'HE PLANNING AND CONSTRUCTION OF the two just described. The smaller offices are 10 feet wide by 20 feet long; those facing the elevator are 25 feet long. There are six fast-running elevators, only two of which are shown on this plan ; two rooms take the place of the L/ I/ isb \i/ d& \| J\-^ r*.,* 1 i NASSAU STREET FIG. 34. NATIONAL HANK OF COMMERCE HUILDING. other four on the upper stories, with three windows opening into the large court. The offices are well lighted; in fact, the window takes up almost the entire width of each room. Hie stairway is placed at the extreme end and in the least desirable portion of the building. COMMERCIAL CABLK BUILDING TYPICAL FLOOR-PLAN. The Commercial Cable Building, situated at \ T OS. 20 and 22 Broad Street and Nos. 18 and 20 New Street, immediately HIGH OFFICE-BUILDINGS. 73 Fie. 35. ST. PATI. Hni.nt.NG, NEW YORK. (,Geo. B. Post, Arcliitect.) 74 THE PLANNING AND CONSTRUCTION OF adjoining the Stock Exchange, lias for its tenants mostly brokers. The typical floors are so arranged as to accommo- date very small, medium, and large sized offices, the small offices being but 9 feet 3 inches wide by 16 feet 6 inches long, and others 15x16 feet. There being but seventeen offices on each floor and two courts on each side, with the two street fronts, outside light is admitted to every room. (See Fig 36.) The building is equipped with six electric elevators of the screw type, which will be fully explained under " Ele- vators/' GOOD ELEVATOR SERVICE AND TOILET ARRANGEMENTS. It will be particularly noticed by any one examining these different floor-plans that the elevators are all grouped to- gether, and, further, that in the majority of cases they are equidistant from the extreme offices. If this is not so ar- ranged, it will be found that the street entrance governs, in a great measure, their exact location. The success of most of the high buildings is involved in the elevator service with which they are supplied. As the height of the building and the tenancy increase the demands of carriage become urgent to a great degree. They must be capable of the utmost certainty and regularity. The different systems, viz., hydraulic, steam, and electric, each have their advocates, and it is not in the scope of this work to make any comparison as to their merits; but we have to prepare the plans for each in allowing sufficient space for their cages and guide-work. The hydraulic will require. if it has vertical cylinders, a space back of cages or in a sepa- rate shaft about 4 feet square for each cylinder. If electricity is used, this need not be provided. The cages should be at least 6 feet wide by 5 feet in depth, and the ropes capable of lifting about 2500 pounds, running at a speed of 350 to 450 feet per minute. HIGH OFFICE-BUILDINGS. 75 NEW STREET BROAD STREET Fir,. 36. COMMERCIAL CAULK BUILDING. (.Harding- & Gooch, Architects.) 76 THE PLANNING AND CONSl^RUCTION OF It is not altogether necessary that every elevator-builder must have special and individual conditions to place his ma- chinery. "While it is possible, if you hold a car long enough at the lower landing, to pack in fifteen or twenty people, and must necessarily have floor-space to accommodate this num- ber, it is not generally wise to so plan the elevators. More can be accomplished with two small rapid-running cars than a large one making fewer trips. It has been found in modern service, from actual count, that the average number of pas- sengers carried will not exceed six people or even five, and in many cases falls below this ; therefore, if we plan for actual Moor-space, to have, as mentioned above, 25 to 30 square feet, we are giving ample room for ten to twelve people; in other words, multiply the number of elevators to take care of the patrons of the building rather than decrease in number and increase in floor-space of cars. For side-post construction allow 5 inches on each side of the car; if cars are grooved on the sides, with a pilaster in- side, this distance can be reduced to 3 inches. (The thick- ness of car being 2 inches, this makes 5 inches from inside to cross-beams; this is. of course, providing the shaft is per- fectly plumb, which it seldom is.) The counterweight will occupy a space of 3 to 4 inches by 2 to 3 feet in width, as circumstances require: usually the counterweight can be placed to one side of the guide-posts, requiring no more room _than indicated for side-posts. If corner guideways are used, very little, if any. room is gained; but the writer prefers the side-guides. From the under side of overhead sheave-beams at least 12 feet should be provided from the upper floor of shaft, or 16 feet in all. and a pit of 2 feet to 2 feet 6 inches in depth should be provided below the level of the lower landing. HIGH OFFICE-BUILD INGS. 77 For a model hydraulic plant the reader is referred to the Central Bank Building in another chapter. Up to a comparatively recent date 250 feet per minute was regarded as a high speed for an elevator, and no diffi- culty was experienced in controlling by the old system of the hand cord or rod passing through the car; the elevator of to- day, however, demands a much higher speed. At such high speeds it is impossible to control by the old methods; there- fore, it becomes necessary to use other devices, such as the lever and hand-wheel. The lever device, when properly ad- justed, handles the car with a nicety, the lever operating a pilot-valve, which in turn operates the main valve to the cyl- inder. This has, it is claimed, some very serious objections, in that there is sometimes an uncertain stopping and starting often felt in cars so fitted. There are other devices which have direct connection with and control of the main valve without the use of an in- termediate or pilot-valve. If in the nature of the plan it is not passible to place a freight elevator for lifting safes, furniture, etc.. in a separate shaft at another point in the building, one of the passenger elevators should be provided to carry at least 6000 pounds at a slower speed and to have the entire front of the enclos- ure open. The toilets of the high buildings require careful consid- eration; they should be placed in a light-well, the outside being more valuable for office-room. For the number of closets to the floor there seems to be a great difference of opinion. In the Tract Society Building there are nine offices to each closet; in the Bank of Commerce Building and Commercial Cable Building six to each closet. Very many buildings are arranged without closets on each floor, but they are all placed on one story. This is no 78 THE PLANNING AND CONSTRUCTION OF doubt simpler and cheaper, but it is often forgotten that the additional elevator service for this travel causes an increased running expense. In the St. Paul Building the toilets are so arranged. There is a ladies' toilet on each floor and a men's toilet con- taining urinals and slop-sink, while the men's toilet-room with closets is situated upon the ninth story. In all those plans which have the men's toilet on each floor it is customary to have the ladies' upon the fifth and tenth if the building is fifteen stories, and upon the seventh and fifteenth if the building is twenty stories, in height. The writer is of the opinion that it is better to place the men's toilet on each floor. This is his practice, and he has found it desired by the majority of tenants. ]f the toilets should be arranged upon a separate floor, the number of closets, etc., may be considerably less than the whole number on all floors. The closets require for each a space 2 feet 9 inches wide, centre to centre of marble partition, by 4 feet 6 inches deep; for each urinal 2 feet wide; for each wash-basin 2^ feet 6 inches wide. If the toilet-room has six closets, or one for every six offices, there should be two urinals, two wash-basins, and a slop-sink. Hach office or suite of offices should be supplied with one basin. For convenience of arrangement, etc., con- sult the article on " Plumbing.'' In examining very many plans of Chicago office-build- ings the writer finds that the majority of offices are provided with vaults built of fire-proof materials. \Yliile these may be desirable to tenants, they are very seldom, if ever, fur- nished in the New York offices. Electricity furnishes all these modern buildings with light, either from the street main or by special plants pro- II 1C, If OFFICE-BUILDINGS. 79 vided in the basement; but it is quite necessary to provide one or t\va lines of gas-piping arranged in combination fixtures at or near the stairway and in the toilet-rooms. Then, again, there has been placed in several of our high buildings a refrigerating plant to provide ice-water to a fountain placed in the corridor of each floor. This adds but EXCHANGE PLACE FK;. 37. LORD'S COTRT Hrn.nixo. (John T. Williams, Archittx't., a small amount to the cost of the plant in the beginning, and is an attraction to the tenants. LORD'S COURT BUILDING TYPICAL FLOOR-PLAN. The plan Fig. 37 is Ford's Court Building, situated at the south- west corner of \Yilliam Street and Fxchange Place, on a peculiar-shaped plot of ground containing about 12.000 square feet. The building is 214 feet high from the sidewalk. and contains fifteen stories. 8O THE PLANNING AND CONSTRUCTION OF The constructive metal-work is of wrought steel through- out, the connections being designed with particular reference to the lateral stresses incidental to such tall structures, es- pecially in the long wing, where heavy beams and knee- braces are used. The offices are well planned as to light; all easy of access to elevators and toilets. The corridors and toilet-rooms throughout are finished with white Italian marble wainscot- ing and the floors of marble mosaic. The main entrance- hall and stairways throughout are finished in fine marbles. This building is equipped with an independent plant, which supplies from its three high-pressure boilers in the basement all the power for the five electric elevators and lighting. There are seventeen lines of vertical riser-pipes and returns which supply steam to 519 radiators. The building is as complete as modern improvements can make it, being supplied, in addition to the above, with fire- lines in hall with hose attachments, mail-chutes, and a sys- tem of iron tubes, vertically and horizontally carried throughout to all the offices, for the insertion of telephone and district-messenger service. HIGH OFFICE-BUILDINGS. 8 1 CHAPTER III. THE CENTRAL BANK BUILDING. As there is no better way of treating our subject than by describing excellent examples, the writer presents at once a modern skeleton structure, the Central Bank Building (Fig. 38), situated at the northeast corner of Broadway and Pearl Street, New York; John T. \Yilliams, architect and builder. It is built upon a plot of ground 75 feet on Broadway by 150 feet on Pearl Street, containing 11,270 square feet, and is 215 feet from curb to top of roof-beams, containing fifteen stories above and two below the sidewalk. The work was executed as follows : Foundation begun July 10, 1896. First granite base set July 31, 1896. Iron men began work August 7, 1896. First column set August 10, 1896. Roof-columns set October 23, 1896. Roof enclosed October 30, 1896. The plate (Fig. 39) shows the condition of the building October 24, 1896. The view (Fig. 40) was photographed November 14, 1896. The fronts were completed December 9, 1896. At the same time the plastering, steam-piping, plumbing, etc.. were considerably advanced, and the build- ing was ready for occupancy the latter part of this month, the entire work being wholly completed in the short period of seven months. Tin-: ARCHITECTURAL STYLE of the building is that of the Grecian Doric, the oldest type of the classic group, from 82 THE PLANNING AND CONSTRUCTION OF which many of our recent and most successful buildings can trace descent. The conditions and spirit of modernity must necessarily be recognized in the application of a style of such antiquity, which, while reflecting the highest culture and genius of a period of architectural excellence, was untrammelled by commercial restrictions and nineteenth-century influences. The architectural designer of to-day is confronted with a difficult problem, more serious than his predecessors were ever called upon to solve, and in this country we have cer- tainly added to his task by prescribing at times altitudes hitherto unknown in architectural practice. Jn the Central Bank Building a reasonable limit to ver- tical dimension has been fortunately recognized, and by a studied relation of the three emphasized horizontal divisions to the height a highly creditable composition has been added to the commercial structures on Broadway. The Doric order through its lintilar style offers an im- portant r.rgument in favor of its adoption in commercial buildings; and, again, from its character of solidity and re- pose, its appropriateness to heavy structures is unquestioned. In this particular building its selection undoubtedly suggests the purpose or " estimation " of the structure, the home of a metropolitan national bank. To emphasize this idea, the two-story columnar order occurring in the basement treat- ment is elevated on a bold rusticated subbase the height of the main story. This wall is frankly pierced for windows, the sharp arrises and dee]) jambs rather tending to accentu- ate the quality of a suborder. This arrangement relieves the base-line of serious irregularity and permits unobstructed passage along the sidewalk and- about the entrance to the building. T-he three stories just referred to, together with an attic, Fu;. 38. CKNTKAL HANK Bi ILDINC, XK\V YORK. (Julin T. Williams, Architect.' HIGH OFFICE-BUILDINGS. 8$ are constructed of granite and complete the basement of the structure. The metope of the entablature over the col- umnar order is filled with carving emblematic of American Commerce, Peace, Progress, and Prosperity. The superstructure consists of a rusticated shaft includ- ing eight stories and what may be termed a neck-band of two additional stories; above this is an entablature (propor- tioned to the entire structure as an order) absorbing the in- terval from the fourteenth-story lintels to the highest mem- ber of the main cornice over the fifteenth story. All this work has been carried out in brick and terra-cotta. Of the shaft proper the fenestration has been kept ex- ceedingly simple, a decorative motif being secured by fram- ing groups of four windows in consecutive double stories, but preserving a marginal sequence of single openings around the collective group. All openings show empha- sized lintels which are introduced between the recessed courses of brick forming the lines of rustication. A table moulding serves as the line of demarcation be- tween this shaft and the superimposed stories, and leads to the change in member of the order. The thirteenth and fourteenth stories are treated together, and to more clearly define the neck-band the rustications are omitted. The flank windows are framed in an archivolt and crowned with a pediment. This pediment and the intermediate panel be- tween the two orders of stories are enriched with a modelled ornament. On the Broadway facade the interval between the flank windows is treated in the style of the columnar order in the basement group, but of course in terra-cotta. These Doric columns are believed to be the first of the ( ire- cian order ever made of this material, at least it is so stated in a recent issue of a well-known architectural journal. On the Pearl Street front the intermediate windows be- 86 THE PLANNING AND CONSTRUCTION OF tween flanks are treated as wall-perforations, the floor-screen being panelled to preserve the continuity of the vertical jamb-lines and so further the general union of the two stories. The entablature over this order is kept subordinate, evi- dently with the object of making it appear as an architrave to the main entablature of the structure. This has been successfully done, and the strong accentuation of the orna- mented panels on the face of the fifteenth-story piers sug- gests a vigorous triglyph motif, free from the abnormal effect that a conventional treatment would have caused. The lintel course over the fifteenth story performs the other func- tion of the astragal members over the triglyphs; and finally we have a strong and bold cornice of some () feet projection with a coffered soffit, providing a valuable medium for the play of reflected light. The flat cymatium, decorated with well-defined and oft-recurring lions' heads, lends interest to the sky-line and suitably completes the composition in a manner both rational and accordant with the fitness of tilings. OFFICF A KR. \xr.ian-: XT. There are over three hundred and fifty well-lighted offices (see plan. Fig. 41), the majority of which open on the Broadway and Pearl Street sides, and the others into two large open courts facing northward. There are live large elevators conveniently situated, with a large elevator-hall in front, into which the corridor. .) the Upper (>ut- 107 HIGH OFFICE-BUILDINGS. 1 09 gone throughout the country from time to time. Architects and engineers have demonstrated that they are fully able to cope w 1 'th all these questions of modern building-construc- tion, and though such criticisms continue to be made high buildings continue to be built. The writer believes in a limitation of height of buildings to the extent heretofore mentioned, but he is impressed with the fact that all these criticisms (excepting a few) emanate from a lack of practical knowledge regarding the material and construction of high buildings. In the evolution of the modern office-building it is a fact that a building without masonry walls has ceased to be a wonder. Steel and concrete foundations and steel frames^ supplanting for the same purpose the old timber of our fore- fathers, have long since, by a mere change of material, en- abled us to build houses of enormous size with safety and economy. The Fisher Building of Chicago, an eighteen-story and attic office-building, has three fronts on three different streets, and these fronts are covered with cellular terra-cotta on the outside, not in imitation of a wall, but following up- ward the steel supporting members and closing in the tran- soms between the windows, leaving two thirds of the exterior to be enclosed with glass. On the inside the outline of the rooms is denned by porous terra-cotta blocks. The only suggestion of a wall in the building is the former, but this is not practically a wall, for it is supported independently at every floor-level. Bricks were employed only in backing up. and in strengthening the terra-cotta. The steelwork of the building was started October 12. 1895, the top story November u; and the third, fourth, and fifth stories were enclosed, while the first and second stories 1 10 THE PLANNING AND CONSTRUCTION OF -\\'AI-I.-SKCTION, CENTRAL BANK BUILDING. FIG. 48. WALL-SECTION REC- OMMKNDED KY WRITER. HIGH OFFICE-BUILDINGS. Ill remained open. This fact clearly proves our argument that the thick and heavy walls required by the New York la\v arc- quite unnecessary. EXTERIOR WALLS OF TIII-: CENTRAL BANK BUILDING. The party-walls of the Central Bank Building- are built strictly according to the Xew York law, and are shown by the illustration Fig. 47. The cellar-wall is 36 inches thick: basement, 32 inches ; first story, 28 inches ; second and third stories, 24 inches ; fourth, fifth, sixth, and seventh stories, 20 inches; eighth, ninth, tenth, and eleventh stories, jo inches; and the four upper stories, 12 inches. For decorative effect the exterior walls facing 1 'roadway and Pearl Street are 28 inches for the first and second stories, and 24 inches from the second to the roof. At every floor- level above the fourth story in each panel between the ver- tical columns there is inserted a girder composed of two steel beams supporting the brick masonry of each and every story, transferring the weight to the columns, and any one of the panels could be removed without detriment to the one di- rectly above. Below the fourth floor-level a single beam is inserted at each tier of beams to act as a strut and tie for the columns, and the weight of the masonry is carried directly to the foun- dations. The above is also provided for in the Xew York law, as follows : " XYhen the curtain-walls are 20 inches or more in thick- ness and rest directly on the foundation-walls the ends of all beams may be placed directly thereon, but at or near the floor-line of each story ties of iron or steel encased in the brickwork shall rigidly connect the columns together hori- zontally." This, in the writer's opinion and experience, is not a sat- 112 THE PLANNING AND CONSURUCTION OF HIGH OFFICE-BUILDINGS. 113 isfactory tie for the lower columns of such high structures. It is preferable to insert sufficient beams to carry the panel loads, as is done in the upper stories, and connect the floor- beams in a similar manner, thus giving to the framework greater rigidity. \Ye present the wall-section, Fig. 48, for buildings of FIG. 50. DKTAII.S OF TIIIKD-S TORY LINTKI.S AND CORNICE. CENTRAL HANK Mni.niNc. fifteen stories or less, and feel justified in recommending it as meeting all the requirements of a properly constructed skele- ton-frame. The nine upper stories are to be enclosed with a 12-inch brick or concrete wall lined with porous terra-cotta hollow blocks, and the lower stories to be built of a H>-inch wall and lined in a similar manner. Kach panel is to be sup- 114 THE PLANNING AND CONSTRUCTION OF ported at each floor-level with a girder of sufficient strength to carry its respective wall. The columns and total loads are to be supported upon the foundation as shown and de- scribed under " Cantilever Girders." FIG. 51. DETAIL OF THIRTEENTH-STORY CORNER WINDOW, CKNTKAI, BANK BUILDING. KXTKRIOR \YALLS DKCORATKD. There has been consid- erable improvement in connection with brick masonry as a direct result of the use of steel construction, and we find, consequently, that more care is taken in filling the joints, HIGH OFFICE-BUILDINGS. U Il6 THE PLANNING AND CONSTRUCTION OF and the work is laid up more solidly in pure cement mortar, which is necessary to protect the steel from corrosion. A structure erected in accordance with the best practice of the day gives a better opportunity for the use of decora- tive terra-cotta, moulded and tinted bricks and all varieties of stone ashlar. Terra-cotta as a building material for the exterior walls has very many advantages. It affords architects an oppor- tunity to see the actual full-size details of the more orna- mental portion of their design before the work is burned, as where no repetition is intended no moulds are used, and the work which is afterward to be burned and take its place on the building is the model itself. Another important and practical point is its comparative lightness to stone. For building purposes it is generally made of hollow blocks, formed with webs inside so as tc give extra strength and to keep the work true while drying. After each block is set in its proper place the hollow portions are rilled in with brick and cement. The lightness of terra-cotta, combined with its resisting strength, and taken in connection with its durability and in- destructibility, renders it especially desirable for use in con- nection with the skeleton-frame. The modern employment of this material embraces col- umns, pilasters, capitals and bases, sills, jambs, mullions and lintels, skew-backs, arches and keys in fact everything per- taining to the decoration of the exterior. In the exterior walls of the Central Bank Building above the granite base of the first, second, third, and fourth stories of the Broadway front, and above the first story of a portion of the Pearl Street front, terra-cotta was used with taste and judgment. The illustration Fig. 49 shows the spandrels of the Pearl Street second-storv windows. The terra-cotta is HIGH OFFICE-BUILDINGS, 117 * 4-S----4- . 5* FK;. 53. TERRA-COTTA COLUMN, THIRTEENTH AND FOURTEENTH STORIES, CENTRAL BANK BUILDING. Il8 THE PLANNING AND CONSTRUCTION OF made with ribs and the section shows the brick backing 12 inches thick, the entire spandrel being supported by a steel beam and channel. The illustration Fig. 50 shows the arched lintels of the third-story windows and the cornice above the third story, all of which is supported in the same manner as the spandrels mentioned above. The illustration Fig. 51 shows the corner windows of the fourteenth story, and the illustration Fig. 52 is the main cornice of the building. This cornice has a projection of 6 feet, and is supported by 6-inch steel-beam cantilevers extended back onto the roof and there secured to a 1 2-inch steel channel running along the entire front, and further secured to the roof-beams, mak- ing a strong and effective appearance. The illustration Fig. 53 shows the terra-cotta columns of the thirteenth and fourteenth stories. HIGH OFFICE-BUILDINGS. CHAPTER V. FLOOR-CONSTRUCTION AND FIREPROOFING. THE present flooring system of steel beams in connec- tion with other material which has been adopted by archi- tects and engineers for modern building-construction methods has no doubt been settled for some time to come. In fact, the system seems to answer all requirements, and is economical. In the designing of such floors the arrangement must be such that the material is used in the most economical man- ner; every member must be calculated. There must be suf- ficient material no more, nor less; for it is essential not only for economy, but also to reduce the weights of the dead loads on the joints, columns, and foundations, and the con- struction should be as light as consistent with perfect sta- bility. The loads to be supported by the construction govern the design of the flooring system. The dead load comprising all the materials used as a part of the construction that is, floor-beams, arches, floors, and partitions and the live load the weight of persons, office furniture, stores, and movable goods. LIVE LOADS. The building laws of the different cities provide for the live load to be carried by these floor-systems. The Xew York and Boston laws require 100 pounds per superficial foot, and the law of Chicago 70 pounds, with proper reduction for columns, etc. I2O THE PLANNING AND CONSTRUCTION OF For proper economy 100 pounds is certainly too much, 70 pounds is high, and for an average 50 pounds would no doubt be sufficient. \Ye recommend 60 pounds for beams, 50 pounds for girders, and for columns 40 pounds, the office floor, halls, and toilets not included. The Xe\v York law requires that the total live load be assumed by columns and girders, but the Chicago law makes this distinction: " It is quite possible that the beams may carry their full capacity of live loads, while the chances are increasingly less that the girders or columns will ever be required to carry anywhere near their full capacity if a full load had been assumed.'' Messrs. Blackall & Everett, Boston architects, in their experiments of live loads upon some of the large Boston office-buildings, found that in 210 offices in the Rogers. Ames, and Adams buildings an average of 16.3 pounds per square foot was found for the Rogers Building, i / pounds for the Ames, and 16.2 pounds for the Adams Building. The greatest moving load in any one office in the three buildings was 40.2 pounds per square foot, while the average for the heaviest ten offices in each of these buildings was 33.3 pounds per square foot. Mr. Blackall came to the conclu- sion that " if these figures are to be trusted to any extent whatever, then even under the most extreme conditions, tak- ing a pick of the heaviest offices in the city and combining them into one tier of ten offices, the average load per square foot would be only a trifle over 33 pounds, while for all pur- poses for strength an assumption of 20 pounds would be ample in determining the loads on the foundation, as well as the columns of the lower stories." The Boston building law requires that the floor-construc- tion be so designed as to carry the following live loads : Dwellings, 50 pounds; office floors. 100 pounds; public HIGH OFFICE-BUILDINGS. 121 buildings, 150 pounds; and for stores and warehouses, 250 pounds. The Chicago law : 70 pounds for all office-buildings, buildings used as residences for three or more families, and all hotels, boarding or lodging houses occupied by twenty- five or more persons. The New York law: 70 pounds for dwellings and hotels, 100 pounds for offices, 120 pounds for public buildings, 150 pounds and upward for factories, warehouses, and stores. DEAD LOADS. In dead loads we have actual weight to provide for, and the Xew York law states that " all brick or stone arches placed between iron or steel beams shall be at least 4 inches thick and have a rise of at least i] inches to each foot of span between the beams. Arches of over 5 feet span shall be increased in thickness as required by the Super- intendent of Buildings. '' Or the space between the beams may be filled in with sectional hollow brick of hard burned clay, porous terra- cotta or some equally good fire-proof materials, having a depth of not less than i-j inches to each foot of span, a vari- able distance being allowed of not over 6 inches in the span between the beams." Dead Floor-weights in the Central Bank Building. The dead floor-weights, as actually weighed by the writer and used in the Central Bank Building, were as follows, in pounds per square foot of surface : 7 pounds steel ~- beams, tie-rods, bolts, and angles. 32 arches = porous terra-cotta 8 inches thick. 1.5 sleepers = spruce sleepers 3x4 inches, bev- elled; 1 8 inches centres. 2.5 rough flooring = yellow pine, tongucd and grooved. 122 THE PLANNING AND CONSTRUCTION OF 3 . 5 pounds finished flooring = = maple, tongued and grooved. 22 " filling = ash concrete, dry, about 6 inches thick. 22 partitions == terra-cotta blocks, 3 inches, and plastered, assuming that the weight of the partitions would be distributed over the beams, and a possibility that they would be changed at any time. 7 . i plastering = ceiling of rooms, dry-plastering. 95.6 " = Total. Dead Floor-loads in the Old Colony Building, CJiicago. In the Old Colony Building, Chicago, the following dead weights were assumed : Flooring 4 pounds. Deadening 18 Tile arches 35 Iron 10 Plastering 5 Partitions 18 Total 90 The dead and live loads used in the calculation of the floor-system, in pounds per square foot, were as follows : Beams. Girders. Columns. Footings. Live 70 50 40 Dead 90 90 90 90 Total 1 60 140 130 90 HIGH OFFICE-BUILDINGS. 12$ Dead Floor-loads in the Marshall Field Building, Chicago. In the annex of the Marshall Field Building, Chicago, the dead loads were as follows : Flooring, |-inch maple 4 pounds. Deadening 9 Fifteen-inch tile arch 45 Iron 12 " Plaster 5 " Partitions, 3-inch Mackolite 20 Total 95 " As the above figures refer only to the office-Moor, other calculations are required for toilet-rooms and corridors which have no wooden floors, but are covered with mosaics and have the partition covered with marble wainscoting. In these cases the total dead weight will be increased. Such floors weigh on an average, 125 pounds per square foot. TYPICAL FLOOR-FLAX OF CENTRAL BANK BUILDING. The illustration. Fig. 54, shows a typical beam-plan of the Central Bank Building which supports the dead loads of the floors. The columns were arranged in such a manner as to equalize the loads as much as possible upon the foundation, all of them being placed about 15 feet apart, the girders and beams being as nearly the same length as it was possible to make them; thus, it will be seen, giving an economical ar- rangement. The illustration. Fig. 55. is an enlarged panel between four columns. The girders are all single 1 5-inch. 41 pounds per foot, steel beams, resting upon beam seats and secured to the columns by knees as shown. The regular floor-beams are all 9-inch, light section, steel. 21 pounds per foot. These 124 THE PLANNING AND CONSTRUCTION OF H f -H y-J JL -"M i r- u HIGH OFFICE-BUILDINGS. 125 beams are secured by knees to tbe girders and set i^ inches below the top of the same, thus cheapening the construction by the omission of flange-coping. It will be noticed in this pf] L_ J LJ L J Fin. 55. Fi.ooR-r.\.\KL IN CKNTKAI. HANK HI-ILDIM;. illustration that the tie-rod holes are within 3 inches of the bottom of the Q-inch beams. This is important, and is very necessary for the reason that too many arches have fallen out of floors on account of the tie-rods not being low enough to resist the thrust of the Moor-weight. 126 THE PLANNING AND CONSTRUCTION OF FIREPROOFING FLOORS. The fireproofing of such floors, in the broad sense in which the term is now applied, should embrace incombustible material used in the construc- tion, and it should be of such a character that it will effectu- ally resist disintegration and retain its strength and firmness under all the conditions that may arise in the conflagration and the subsequent operations of a fire-department. For many years there has been a demand for safe and economical systems. This demand has led to the introduc- Fir,. 56. COI.TMBIAN METHOD. tion of many systems of more or less merit, a number of which may. however, be said to be in the experimental state. The consequence is that a few of our so-called fire-proof buildings, on account of imperfect and experimental con- struction, are not actually fire-proof. It is a fallacy, to a large extent believed in, that iron is the only material for so-called fire-proof construction, and that the only building capable of effectually resisting fire i* one into the construction of which iron enters as a substitute for wood. Admirable as such construction mav be when //A/// O/-'I-'1CI\-B L '//, I) INGS. 127 properly built, it should he remembered that iron, hy reason < if its tendency to expand in severe heat and hy reason of its liability to bend and break in high temperature, is a most dangerous material unless protected from the effects of tire. Buildings constructed with iron beams and hollow-brick loss has caused extra efforts to be put forth by the promoters of non-combustible methods for its manufacture. The question is asked time and again. " Can a building be made fireproof ? " \Ye maintain that a building can not only be erected fireproof, but that when so designed is neces- sarily constructed of material proof against the action of lire, and at the same time much more substantial and time-endur- ing than a combustible form of construction. The term fire-proof, when applied to a building, contem- plates that the edifice in all its structural parts shall be formed entirely of non-combustible material meaning therebv that all the interior and exterior of the structure shall be built in a manner calculated to successfully resist the injurious action of extreme heal and cold water. The partitions for dividing the various floors into rooms. corridors, etc.. should be built of absolutelv non-combustible material, and when the roof and upper ceiling of the building are treated similarly all danger of spread of lire is made im- possible. The use of various materials introduced for the purpose' of lire-proof protection has been more or less effective. The general, and perhaps to-dav the oldest, modern svstem for floor-construction has been the brick arch between iron beams; then followed the corrugated iron and concrete arch, the hollow tile, flat arch, and numerous others herein de- tailed and described. All these systems have their advan- tages, and any one of them is much to be preferred to a wooden form of construction; but they have disadvantages also, when compared one with the other. The question, then, is to determine which method of con- >truction is the 1 best and has the fewest detects. Of the use of concrete in construction little need be said. UK; ii o /'// c /:-/>' i n.n /.W/.Y. 1 29 It is a conceded fact by those authorities who have given the subject the most thorough and careful stndv that concrete, as a fire-resisting material, is unequalled. After the threat conflagration in Chicago the committee who examined the effects of this tire reported that concrete was the most thoroughly tire-resisting material that had passed through the ordeal. I ron and steel, when completely embedded in and pro- tected by the concrete which forms around it in a homo5. 138 THE PLANNING AND CONSTRUCTION OF DEAD LOAD PER SQUARE FOOT OF THE COLUMBIAN SYSTEM. In office-buildings with level ceilings the follow- ing weights are calculated as dead loads in the Columbian system: Concrete, weighing on an average of 135 pounds per cubic foot,, and 9-inch beams being used as in the illus- tration Fig. 54 with the same material as used in the Central Bank Building : 7.0 pounds steel = beams, tie-rods, bolts, and angles. 50.6 " concrete -~= 2^-inch concrete floor and 2-inch concrete ceiling. 1.5 sleepers = spruce sleepers, 3 x 4-inch, bevelled, 1 8-inch centres. 2.5 rough flooring = yellow pine, tongued and grooved. 3.5 finished flooring = maple, tongued and grooved. 18.6 filling = ashes and concrete about 3 inches thick. 7.1 plastering = ceiling of rooms. = Total. If the loads of the partitions were assumed to be placed upon the beams, there would be an additional weight of 20 pounds, making a total of uo.8 pounds. THE ROEBLIXG FLOOR-ARCH.- The Roebling system of fire-proof floors and ceilings, constructed as herein illus- trated, consists of a wire-cloth arch stiffened by steel rods, which is sprung between the floor-beams and abuts into the seat formed by the web and lower flange of the I beams. On this wire arch Portland-cement concrete is deposited and al- lowed to harden. The result is a pleasing monolithic con- struction that fulfils the requirements of a floor. THE ROEBLIXG SYSTEM CEILIXG. The ceiling construc- tion consists of a system of supporting rods attached to the /// inches, and using lo-inch 1 beams, as per Fig. 60, the weights are as follows : 7 pounds steel beams, tie-rods, bolts, and angles. 33 concrete filling to top of beams. 10 ash concrete between sleepers. 1.5 ' sleepers- '-.spruce sleepers. 2x3 inches, bevelled, 1 8-inch centres. 2.5 ' rough flooring yellow pine, tongued and grooved. 3.5 ' finished flooring maple, tongued and grooved. 7.5 ' plastering- ceilings of rooms. 1.1 ' ceiling construction. 1.3' wire centring for arches. 67.4 ' Total. If the partitions were assumed to be placed on the floor, as in the Columbian system, 20 pounds would be additional, making a total of 87.4 pounds per square foot. FIRE AND WATER TEST OF THE ROEIJLINC, FI.OOR- SYSTEM. This floor-arch, tested by the Xew York I'uilding Department, consisted of lo-inch I beams, 4 feet centres, the wire arch being covered on the top with concrete consisting' 140 THE FLAX XING AXD CONSTRUCTION OF of i part of Aalborg Portland cement, 2 parts sand, and 5 parts of steam ashes. The concrete \vas levelled Hush with the I beams, producing an arch having haunches about 9 inches dee]) and a crown 3 inches thick at the middle of the span. Nailing-sleepers 2 v 3 inches were laid crosswise over the top of the beams at intervals of about 16 inches, and Fi<;. 66. TIIK ROKKI.IM; FI.OOK-ARCH AND CKII.IM;. concrete, composed of i part Portland cement, 2 parts sand, and 10 parts steam ashes, was tilled in between to a depth of 2 inches. The flat ceiling construction under two of the arches consisted of 5-16" round iron rods, at- tached by i-inch offset clips to the lower tlange of the i beams. Stiffened wire lathing was laced to these support- ing rods, to which was applied machine-mixed mortar gauged with plaster of Paris. There was an air-space aver- aging about 4 inches in depth between the Hat ceiling and the floor-arches. 1 hiration of fire-test. 11.10 A.M. to u.^S P.M.; tempera- //A;// oj-t-iCK-Ki'ii.DiNds. 141 tnrc, u.oi P.M., 2(X)O decrees; 12.10 P.M.. 2150 degrees; 12. 10 to 12.45 I> - M -. -J5 to -400 degrees. At the con- clusion of the fire-test the plastered ceiling and exposed con- crete arch were red-hot. A portion of the brown coat of the plaster. 2 feet by 3 feet, had fallen away from the ceiling. After the water-test half the plaster was washed off the ceil- ing, leaving the wire netting exposed at some places. The concrete floor-arches, including the one exposed, were intact and uninjured. The final deflection of the 1 beams, after cooling and removing load, was imperceptible. A 5-hour test of an arch similar to the one above was made. At the conclusion of the tire-test the ceiling false work and plastering had fallen down and the lloor had de- flected perceptibly. The wire centring and the under side of the rloor-arches were red-hot. After the water-test the floor-arches were found to be apparently uninjured. The lire-streams loosened a couple of the ribs of the wire centring, but had little or no effect on the concrete arch. After cool- ing the test load of ooo pounds per square foot was applied without any indication of failure. A 4-foot section of one of the floor-arches so tested was subsequently cut free from the rest of the floor and tested for strength by the Building Department. The iron beams were supported by timber posts from below and a concen- trated load of 41.000 pounds was placed on an area of 10 square feet in the middle portion of the arch. Deflection of arch between the beams ''\ inch. After removing the load the arch recovered, the final deflection being .] inch. The following table of weights, etc.. may be of service in desi* . crete and wire. 8" 4 o" 9" 4' 6" 10" 5' o" 12" 6' o" 15" 7' 6" 2.S lb 3<> " 33 " V) 53 " In spans of over 5 feet allow \ r, inches clear rise per foot of span. The weights given are for concrete to the level indicated in the first column with a 3-inch crown, and for all wire con- struction, including arch wire for floors and lathing for ceil- ing. The concrete consists of i part of high-grade Portland cement. 2 parts of sand, and 5 parts of clean steam ashes. Add for plaster 8 to 10 pounds per square foot; the weight of the structural iron, of the wood or other finished floor, and of the filling between sleepers, if any, must also be added for the total dead load of floors. HOLLOW-TILE ARCHKS. A porous terra-cotta tile is a name given to a composition of clay and sawdust fashioned into hollow forms and burned into common bricks, in which process of burning the sawdust is consumed, leaving a por- ous earthen tile, having the quality of being tire-proof, sound-proof, dry, light, and capable of resisting, in the form of an arch, when set between floors, a considerable weight. The successful adoption of hollow flat arches in the floors of office-buildings, where they are now so extensively used, shows conclusively that their strength is more than equal to the demands. Heavy safes, weighing from two to five tons, are almost daily moved and placed on these floors, and the lest of practical use they have been subjected to is conclusive HIGH OFFICE-BUILDINGS. 143 evidence that they are sufficient for the purpose for which they are intended. METHOD OF SETTING HOLLOW-TILE ARCHES. The manner in which these blocks are set is as follows: A Hat centre made of 2-inch planking, supported upon 4 < 4-inch joist, hung' to the floor-beams by means of ironwork, is sus- pended below the bottom flanges of the beams at the proper level. The blocks are then placed side by side upon these centres, the joints being" formed with ordinary cement. The joints are broken by means of half-blocks placed alternately at the start. The skew-backs, lengtheners or intermediate blocks, and keys are made of different sixes to accommodate the various spans. \\ hen the joints are fairly set. which in ordinary weather takes from twenty-four to thirty-six hours, the centres arc- slackened down and moved to another portion of the build- ing for further use. The upper surface of the arch is concreted over at a sufficient depth to bed in the concrete the wooden floor- sleepers. TESTS OF SIDE AND END Cox STRUCT ED HOLLOW-TILE ARCHES. Various tests of the hollow-tile arches have been made repeatedly during the past few years, notable among which were those at Denver. Col., under the supervision of Messrs. Andrews. Jaques, and Kantoul. architects. The specification was as follows : A == A still load, increased until the arch is destroyed. B -Shocks, repeated until the arch is destroyed. C ; = Eire and water, alternating until arch is destroyed. D = Continuous tire of high test until arch is destroyed. DESCRIPTION OF ARCHES TESTED. All the arches tested were carried on lo-inch steel I beams weighing 33 pounds per foot, span 5 feet centres. Each pair of I beams wa> tied 144 THE P LA XX I KG AXD COX STRUCTIOX OF with two ;-inch bolts, the bolts being placed 5 feet 4 inches apart, the holes for the bolts being in the middle of the web of the beams. The bottoms of the beams were tied together with two straps made of -i- x i-inch iron, the ends being hooked around the lower flanges of the beams and directly under the bolts. The 1 beams were supported upon four brick piers, the piers being 12 inches square, capped with bond-stone and resting upon footing-stones 2-\ feet square, the footing-stones set upon hard gravel. The illustration Fig. 67 represents the Pioneer Arch, side construction, weighing 32 pounds per square foot. Fir,. 67. SF.CTION OK PIONKKK ARCH TSF.D IN DKNVK.R TESTS rig. 08. the Lee Arch, was made of porous terra-cotta. 34 pounds per square foot. FIG. 6S. SK.rno.N <>i- I.KK END MFTHOI> ARCH rsF.n IN DFNVF.K TKSTS. Fig. 69. the \Yight Arch, weighed 40 1 pounds per square foot, all being weighed dry before setting in the arch. Following is a summary of the tests : 7V,v/ /. St ill-load test ; load isas 1 feet square. Arch A. i. Pioneer Arch, dense tire-clay, side con- struction, broke at 5420 pounds of pig iron. HIGH OFFICE-BUILDINGS. 145 Arch A. 2. Lee Arch, porous terra-cotta, end method of construction, carried 15,145 pounds of pig iron for two hours without breaking. Afterward broken by three blows of a ram weighing 134 pounds and dropped from a height of io feet. Arch A. 3. Wight Arch, of dense fire-clay, side con- >truction, broke at 8574 pounds. Text H. Dropping test. Arch I). 4. Pioneer, of dense fire-clay, side construc- tion, broke at first blow of a ram weighing 134 pounds dropped from a height of 6 feet. Arch B. 5. Lee, of porous terra-cotta, end construe- FH.. (n). SECTION 01-- THK WICHT ARCH USED IN THE DENVER TESTS. tion; same ram dropped on it from a height of 6 feet four times; same ram dropped on it from a height of 8 feet seven times; arch went down at eleventh blow. Arch l\. o. Wight, of dense lire-clay, side construction, broke at first blow of same ram dropped from a height of feet. '/'est C. I : irc and icatcr test. Arch C'. 7. Pioneer, of dense fire-clay, side construc- tion. Three applications destroyed this arch; when the brick lurnace was removed from under this arch collapsed. Arch C". 8. Lee. of porous terra-cotta, end construc- tion. This arch was given eleven applications of the water, and at the end of twenty-four hours was practically unin- jured, as it required eleven blows from the ram used in the dropping test to break the arch clown after the furnace was removed trom under it. 146 THE PLANNING AND CONSTRUCTION OF Arch C. 9. Wight, of dense fire-clay, side construction.. This arch was given fourteen applications of water, and after twenty-four hours very little of the arch was left, and it col- lapsed as soon as the brick furnace was removed from under it. Test D. Continuous fire. Arch I). 10. Pioneer. 9 inches deep, of dense fire-clay, side construction. After having a continuous fire under it for twenty-four hours was destroyed. Arch D. ii. Lee, of porous terra-cotta. end construc- tion. After having a continuous fire under it for twenty- four hours was practically uninjured, as, after the furnace was removed from under it, it supported a weight of bricks of 12,500 pounds on a space 3 feet wide in the middle of the arch. Arch I). 12. \Yight. of dense fire-clay, side construc- tion. After having lire under it for twenty-four hours wa> unable to carry its load of 300 pounds per square foot, and collapsed as soon as the brick setting was removed from under it. In the fire and water tests it was noticeable that the two arches made of dense fire-clay dropped large pieces of the arch at almost every application of the water, while those of porous material were comparatively uninjured at the close of the test. That the porous terra-cotta arches, built as they were here with the so-called end construction, were practically un- injured by the fire-tests is shown by the fact that after the furnaces were entirely removed these two arches not onlv supported their original load of brickwork, but one arch wa> loaded with additional brickwork until a weight of 12.500 pounds had been placed upon it, and the other arch was sub- HIGH OI-FIL'E-BI-ILDIXGS. 1 47 jected to a dropping test and required eleven 1 flows of the piece of timber weighing 134 pounds to break it down. As far as the material goes, the effect of the heat seems to have been worse on the porous terra-cotta than the dense tile. The porous terra-cotta, when subjected to the direct action of the heat, was badly disintegrated, so much so that it could be easily crumbled in the tinkers, but this condition extended up from the bottom only about i inch; above that the material was perfect, and although the bottom webs were disintegrated the arches still stood in place. The material in the dense fire-clay was practically un- injured, but the arch, as a whole, was destroyed, for the reason that large pieces broke off from the bod}' of the arch in almost every case: this took place at the angles of the tiles. The mortar seems to have stood better than the arches themselves. Mr. William M. Scanlan. who was identified with the above tests, states " that there seems to be no reason why porou> tiling should not be chosen as the best material for floor-arches." The clay is mixed with from 50 to no per cent of sawdust by bulk, and then, after thoroughly drying, the material burnt in a down-draft kiln. When the heat in the kiln becomes great enough tho sawdust in the mass of clay ignites and is consumed, thus helping to burn the clay all through evenly, and also leaving little cavities or cells in it. It is much lighter than dense tile, but it has a toughness and resilience that renders it more reliable. A point that is not generally considered is that for the purpose of a floor-arch in the form of hollow tiles an exces- sive crushing strength in the material is a disadvantage, for the reason that the denser and harder the material, the more brittle it is. lie also states that " while manufacturer.-- have varied the 148 THE PLANNING AND CONSTRUCTION OF shapes of tlie end-construction blocks, the original square blocks of porous tile remain the simplest, easiest form to FIG. 70. LEE END-CONSTRUCTION TILE-ARCH. manufacture and to build, and gives the best results.'' Sec Fig. 70, showing a section of the end arch, and Fig. 71 showing the end-construction abutment-tile. KM;. 71. END-CONSTRUCTION ABUTMKNT-TII.K. Fig. 72 is the side-method arch, in which the hollows in the tile run parallel with the supporting beams, and the dis- THK WEAK POINT Kir.. 72. SIDE-METHOD Aucn. Doited line indicates curve of pressure. position of the material in the arch is not at all in accordance with proper method of design, inasmuch as the line of pres- sure of the arch has no solid material through which to act, ///(/// 01-i-lL'E-HUlLDlXGS. 149 and the abutment-blocks arc poorly adapted to withstand a shearing strain (see the weak point " A "). Hence arches built after the side method, when weighted to destruction-, invariably fail at the abutments under a load that does not develop a compressive strain of more than a small fraction of the compressive strength of the material. In the end-construction arch the disposition of the ma- terial is such that all the vertical ribs of pressure act through solid material throughout its whole length. The top and middle webs aid in taking the end pressure at the middle of the span and the only part of the arch that is not in com- pression, vi/.. the bottom of the shell which furnished the level surface for the ceiling plastering. Whether the arch be built on the side or end method, the objectionable feature of the end method is still there, ever tending to spread further apart the supporting beam, necessitating thorough tying together of the beams. I beams not being designed to stand lateral strains, the thrust of the arches must be neutralized by efficient tie-rods close to the bottom of the beams. The desirability of extending the end-construction arch to large spans, and the necessity of making the structure a beam rather than an arch, led to the arch as described below. Tin-: LKK TKXSIOX-ROD HOLLOW-TIM-: FLOORING. The Lee system of Boor-arch consists of porous tile. Portland cement, and cold-drawn steel wires a svstem almost identi- cal with Thaddeus Hyatt's discovery of Portland-cement concrete and the application of tie-bars to the weak part of a concrete-beam construction to supply the needed tensile strength to balance its comparatively enormous compressive strength, making both parts a unit in resistance. \Yhen a straight beam is subjected to a bending -.tress i' becomes more or less curved, bv virtue of which the lower 150 THE PLANNING AND CONSTRUCTION OF part is lengthened and the upper part is shortened in pro- portion to the depth of the beam and the difference in length between the radii of the curves. \Yere the beam made up of horizontal layers, the effect of the stress would be to cause these to slide one upon the other; but the beam being solid, the particles are held together by their own cohesion, the shearing strains being thus opposed by the cohesive face. The primary strain in the beam on the lines of compression and tension being upon curved lines, the disturbed particles must of necessity tend to arrange themselves in harmony with the radical lines of circles, all below the neutral axis seeking extension and all above compression. P. H. Jackson, of San Francisco, took up Hyatt's system after the hitter's death and improved upon it. He employed other forms of ties, such as small 1 beams, for strengthening purposes. Ernest Ransome, of San Francisco, also made an im- portant and commendable improvement upon Hyatt's and Jackson's systems of tension-members, Ransome's system being a square rod twisted. Lee's system of tension-rods laid together are much lighter than those mentioned above, and. the floor being of hollow porous tile, a considerable reduction in weight is therefore gained. PROCKSS OF CONSTRTCTION OF TIIF LFK ARCH. A temporary form of centre of planking is first laid out at the proper height for ceiling lines, upon which the hollow-tile blocks are laid, end to end, in rows from support to support, with space between the rows (see the illustration Fig. 73). Into the space is spread a layer of soft mortar made of Port- land cement and sand; upon this layer the tension-rods are laid and more mortar is put in, entirely surrounding and en- veloping' the rods, and the space is filled to the top of the HIGH OFFICE-BUILDINGS. 151 tiles. The ends of the tile resting in the walls are filled solid with concrete before laying. The anchor-bolts are placed in position within the tiles as they are laid in place. In from four to seven days the form is removed and the floor Fi'.. 73. DKTAM. SKCTION OK THE LKK TENSION-ROD TII.K ARCH. is completed. The floor is united together throughout; in effect and in fact it is one piece. TKST Xo. i OF TIIK LKK TKXSIOX-ROI> SVSTKM. -A test of tin's form of arch was made May 2, 1892. for which a floor 20 feet clear (see illustration Fig. 74) and 4 feet I inch wide was built, supporting about j 5.000 pounds distributed. The floor deflected i inch and showed no rupture. A portion of the load was removed that day, and the rest remained for a day or two. A central load bearing on a space J feet wide, of about nooo pounds, was applied, and left for several weeks without injury. The floor has remained standing out of doors, unprotected up to date, exposed to rain, frost, and heat. It has been tested several times since, and is appar- ently sound with its present load of u.ooo pounds. TF.ST X'o. _' OF TIM-: LKK TKXSIOX-KOD SVSTKM. The following is a summary of a test made in Xew York during April. 1895. of this system : The span was jo feet, total thickness \$\ inches, with a 152 THE PLANNING AND CONSTRUCTION OF cement top; weight of construction, 70 pounds per square foot, or 5600 pounds for the entire floor. Deflection due to dead weight of floor-construction, 7-64 inch. Fn;. 7-). WEKJHT TEST OF THE LEE TENSION-ROD HOLLOW-TILE ARCH. Weight was applied to the floor by piling up bricks as a centre load on an area of 16 square feet. The deflections caused by the loads were as follows : 1940 pounds caused a deflection of 5-64 inch. 3-25 4128 4564 53 ir > 5600 6240 6580 7000 8-64 ] 4-64 1 6-64 1 8-64 19-64 22-64 Upon removing the weight the floor resumed its original position. The uniformly distributed load was 175 pounds per square foot. HIGH OFFICE-BUILD1XGS. '55 TEST No. 3 OF THE LEE TENSION-ROD SYSTEM. A sim- ilar test made upon a 14-foot span arch, with the floors 9-] inches thick, supported a uniformly distributed load of 200 pounds per square foot. The deflections caused by the loads were as follows : 2880 pounds caused a deflection of 3-16 inch. 5400 15-64 " The weights being removed, the floor resumed its orig- inal straightness. THE FAWCKTT FLOOR-CONSTRUCTION. The Fawcett system is an English production, and consists of tubular tiles Fit;. 75.- THK FAWCETT FLOOR ARCH. laid diagonally on the lower flanges of the steel beams, placed 2 feet apart, being the diagonal of the tile at right angles to the I beam. The bottom of the tile is flat (see the illustration Fig. 75), and flanged so as to touch the adjoining one, leaving a space above to receive the concrete. The ends of the tiles are joggled and rest on the beams, serving to protect the under side, a space being left under the same I beam to form a free passage for the air. The concrete on 154 THE PLANNING AND CONSTRUCTION OF the top bears directly on the I beams, thus relieving the strain on the tiles, the under side of which is scored to form a key for the plastering of the ceiling. THE FAWCETT SYSTEM TEST. A test of this system was made by the New York Building Department, 6-inch I beams being used and the tile was covered on the bottom with plastering, and the concrete, consisting of i part of Atlas Portland cement and 5 parts of steam-ashes, was filled in above the tile to a level of 2 inches above the I beams. Duration of the fire-test, 9.33 A.M. to 12.20 P.M.; tempera- ture, 10.30 A.M., 1850 degrees; 10.50 A.M., 2200 degrees. After 1 1. 20 large cracks had formed in the walls, and it was impossible to produce temperature above 1850 degrees. At the conclusion of the fire-test the floor had deflected consid- erably, and the under side of the tile lintels was red-hot. After the water-test the lintels had cracked oft" and fallen away over an area of about 20 square feet, exposing the con- crete filling above. The plaster was oft" over the greater por- tion of the ceiling. The following day the floor success- fully supported the test load of 600 pounds per square foot. The final deflection of the floor was about 3 inches. The ultimate strength was not made. THE RAPP FLOOR-CONSTRUCTION. This is a system of flooring placed in the regular floor-beams, consisting of 2x1-^ inch special tees, as shown in the illustration ( Fig. 76), resting on the lower flange of the I beam, spaced so that a brick will lie between the flanges of the tees, which are held in position by strap-irons bent and fitting the tees closely, forming a tie. These strap-irons, acting as ties, hold the tees rigidly in position, the whole space being filled in with bricks laid flat and grouted with cement and a filling of ashes and cement to the under side of the rough flooring. Tt is capable of sus- HIGH OFP'ICE-B UILD1XGS. taining a load of 800 pounds per square foot, the cost de- pending upon the thickness of the material. Fir,. 7(1. -- R.\ri' FIRE-PROOF FLOOR-CONSTRUCTION. TIIK IvAi-i' SYSTKM TKST. The following data are given of a test made of this system by the Xe\v York Building Depart- ment, the steel 1 beams being 10 inches dee]) by 25 pounds per foot, spaced 4 foot centres and 16 feet span. Duration of lire-test. 10 A.M. to 3 P.M.; temperature at 11 A.M.. 1800 degrees. About an hour after the tire was started a piece of plaster, which covered the bottom of the arch, fell and dis- abled the pyrometer. Subsequent temperatures were indi- cated approximately bv the fusing of copper wire. At the conclusion of the tire-test the greater portion of the plaster- ing had fallen away and the under side of the tloor was red- hot. Some of the light tees sagged somewhat. After the water-test it was found that the lire-stream had disabled a number of the brick in the middle portion ot the ceiling, exposing the cement filling above over an area of about _>o square feet. The tloor later sustained the ooo-pound test successfully. The final deflection was imperceptible. Tin-: M KTROPOI.ITAX FLOOR-ARCH SYSTKM. The Metro- politan floor consists simply of a composition of 75 per cent. 156 THE PLANNING AND CONSTRUCTION OF by weight, of plaster of Paris and 25 per cent of wood chips or sawdust, surrounding the steel beams of the building and forming horizontal Moor-plates between them. These plates contain a series of suspended cables uniformly adjusted to a g-inch round centre-bar and fastened to the top flanges of the floor-beams by hooks made of Xo. 6 coppered wire. The cables are about i inches apart, have a deflection of about 2.> inches, and are composed of Xo. 12 galvanized steel wires twisted together, so as to get a good grip in the body of the plate and reinforce it by their tensile strength. The flange and web protection is cast in permanent moulds of light wire netting, and the floor-plates are cast in tem- porary wooden moulds that are removed as soon as the plaster has set. The ceiling is separate and independent of the floor, and is made of mortar plastered on Roebling Xo. 20 wire netting that is attached to i * -j-inch square transverse bars 16 inches apart, supported from the lower flanges of the floor-beams by 2 '<-' J-inch clips. FIRE AND \YATEK TESTS OF THE METROPOLITAN SYS- TEM. An arch was tested May 19. 1897. by the Xew York Building Department in a manner similar to that described heretofore. The maximum deflection was 36-100 inch, re- turning to 19-100 inch immediately after the fire was quenched, and the floor was practically intact. The ceiling on the farther side, where it sustained the greatest impact of the water, was almost totally destroyed, including the wire 1 netting, only the i / {-inch cross-rods that had supported the latter remaining, the ceiling-plaster having entirely disap- peared. Farther back the netting was not damaged, and and in all places where the water had not struck the plaster had not fallen. The bottom flanges of the beams were ex- posed, the paint being unaffected. The whole of the lower HIGH OFflCE'BL'Il. ])ortion of the floor-plate to the depth of about an inch was softened so as to be easily penetrated by a stick, but it still retained its position and tire-proof qualities except where washed off by the hose-stream, and the floor-slab was intact and otherwise apparently uninjured. Shavings in contact with the lower surface of the floor-beam flanges were found uncharred. When the fireprooring was exposed to the ac- FH;. 77. THK ACMK MK.TIIOD OF FI.OOK-AKCH. tion of the flames, the wood chips were found charred for about an inch from the exposed surface. On May 22 the load on the floor was increased to 600 pounds per square foot over the entire area, producing' a deflection of 44-100 inch. TIIK ACMK FLOOR-ARCH. This arch, Fig. 77. similar to the Fawcett method, is likewise an Fngli>h production. The hollow-tile blocks are placed in a dry state between small 158 THE PLANNING AND CONSTRUCTION OF I beams as shown, requiring no false centring; the concrete is then filled in on top, making a monolith construction of concrete and fire-clay. On account of the added concrete the strength of the floor is increased about 25 per cent above that determined by the beams. THE " MULTIPLEX STEEL-PLATE " FLOOR-ARCH SYSTEM. Fig. 77^7 illustrates a new system of floor-arch, composed of FLOOR LINE LK.X STKKL-PLATK " FI.OOK-AKCH. "E" Fi<;. 77'. C, and /) represent its construction in a simple form, being placed upon the top HIGH OFFICE-BUILDINGS. 159 of the I beams of the floor. In E and /* it is placed upon the bottom flanges of the I beams. /?, C, and 1' have in addition a hanging ceiling, made of wire and plaster, similar to that in the Roebling lloor-arch. This arch is practically the lightest which has come under the inspection of the author, weighing but 35 to 39 pounds per square foot in combination with Portland-cement con- crete, and capable by its construction of sustaining immense loads. \Ye have seen tests of lo-ft. spans with a load of over 550 pounds per square foot where the deflection was less than i inch, while spans of 6 feet with a load of over 1500 pounds per square foot showed the same deflection. \\'e have also seen a span of 6 feet carry safely a load of -'137 pounds per square foot. For office-buildings using 6-ft. spans carrying 150 pounds per square foot the deflection by tests will be but .03 of an inch, and for lo-ft. spans with a load of 150 pounds but .14 of an inch. If the steel plate and concrete be placed upon the top of the 1 beams as at C. and a ceiling of wire and plaster be sus- pended from the plate, there will be a total dead load of not over 55 pounds per square foot. Tin-: PRACTICAL VALUF OF TIII-: DIFFKRKXT SYSTEMS IN Hi'iLiM NC.S, AND Ti-'.STS MY TIM-; WRITER. The value of the different floor svstems in use at the present time lies in pro- tection, in that they furnish both a covering for the steel or supporting members of the building, and bearing power to sustain the floor-weights. As a support for the floors, they a. re capable of carrying with perfect safety any load the floor- beams are designed to bear. As regards their fire-resisting qualities, however, the writer has come 1 to the conclusion that all of the materials if subjected to great heat would be destroyed. l6o THE PLANNING AND CONSTRUCTION OF The tests heretofore described for concrete have been taken from seemingly reliable sources, and in the Pittsburg test of the Columbian method as high a degree of heat as possible was maintained for an hour; in the Roebling test by the Xe\v York Building Department it is stated that the arch was apparently uninjured; in the Boyd-Wilson test the blast was turned on full for one hour and ten minutes, pro- ducing a heat sufficient to consume malleable iron com- pletely. A Portland-cement-concrete block 24 inches long, 8 inches wide, and 4 inches thick was tested by the writer by heating it in a furnace for about fifteen minutes until it was cherry-red-hot on one side; on taking it out and striking it with a shovel it crumbled into powder. Another block of the same material when taken from the furnace was sub- jected to a stream of water from a i-inch garden-hose, which washed the cement and sand clear of the small broken stone. These blocks were made about six months before the tests and were quite dry, the proportion of the material being 2 parts of Portland imported cement, 5 parts sand, and 9 parts small broken stone, a mixture commonly used in founda- tions. To test the efficiency of hard and porous tiles the writer also placed an 8-inch hard-tile floor-block in the furnace for ten minutes, and on lifting it from the fire it fell apart im- mediately: it was red-hot on one side only, its bottom bed separating as in the hard-tile tests already mentioned. An 8-inch porous tile was treated in the same manner; it held together much better, but when the water was thrown on it and it was struck lightly with the shovel it went to pieces completely. In practice the writer has never had occasion to use any- thing except terra-cotta for fi reproofing, but from his inves- tigations upon the subject he has concluded that with any of JflGH OFFICE-BUILDINGS. l6l the systems now used in high office-building construction, where the floors are made solid, the beams entirely covered in a substantial manner, and the columns well protected that is, with a double row of thick blocks any heat likely to be generated would not destroy the structure. In all ex- terior skeleton framework we strive to cover the metal with ordinary building-bricks. PARTITIONS. \Yhere hollow tile and patent blocks are ordinarily used for partitions, steel channels or angles with headpieces of the same material should be placed at the door openings instead of timber studs. FIRE-PROOF BUILDING CONSTRUCTION IN THE PITTSBURG, PA.. FIRE. The fire in Pittsburg. Pa., which occurred on May 3. 1897, ' s important as giving, perhaps, a more severe test of these buildings than any to which the same class of buildings have been subjected before. In view of the magnitude of the fire, and the character of the buildings attacked, a full presentation is thought desirable. The following detailed description is extracted from the Engineering Xe^'s and Architecture and Building, to whose courtesy I am also in- debted for the use of photographs and cuts. To a full understanding of the fire, its origin, and the re- lation of the different buildings to each other, it will be necessary to refer to the map shown in Fig. 78. The fire started in the Jenkins Building (a large grocery-store), and was discovered by the night-watchman in a barrel of paper and other refuse at the bottom of the elevator-shaft. After an effort on the part of the watchman to stop it by means of a chemical fire-extinguisher, which he found unavailing, the fire-department was called, but did not arrive until IJ.JOA.M., 1 62 THE PLANNING AND CONSTRUCTION OF when the fire had gained such headway that ten minutes later the flames burst through the windows, and every floor was burning fiercely. The large store of oil, sugar, molasses, hams, etc., with which the building was filled, furnished abundant food for the flames. The firemen had for some time previously abandoned the FIG. 78. SKETCH-MAI' SHOWING REI.ATIVK LOCATION OK Bm. DINGS BTKNKU IN THE PlTTSBL'RG FlKK, MAY 3, l&<)~. hope of saving the Jenkins Building, and had turned their streams upon the large dry-goods store of Joseph Home & Co. and the neighboring office-building of Durbin Home. Despite their efforts, however, the woodwork of both these buildings near the tops began to burn at about i o'clock, and a few minutes later the flames from the Jenkins Building had leaped the street and set fire to the inflammable contents of the dry-goods store windows. At almost the same time the office-building began to burn. From this time on the spread of the fire was rapid, and a few minutes, according to various reports, were sufficient for both the office and store buildings to become a mass of flames so fierce as to drive the ///(,// OI-I-lCi:-BL'lLDL\GS. 163 firemen from I'enn Avenue and Fifth Street to the roofs of the building's surrounding the fire. FYom these points of vantage at the rear of the Home buildings, and on the far side of Fifth Street, and from the windows of the Methodist Hook Building the firemen directed their streams and pre- \ented the tlames from crossing F"ifth Street or reaching the rear of the Home buildings, but the narrower Cecil Avenue was passed. The new IMiipps Office Building was badly scorched, and the Methodist Book Building, above the fourth floor, was completely gutted of its contents. In ap- proximately two hours from the time of its first discovery, therefore, the tire had destroyed the three larger buildings of the group shown by Fig. 7w-burning c< mstructi< m." I he walls were < >f brick, and the floor-system of wood and stringers carried on iron I beams: the plan \. shaped, with lour sides open to streets and alleys; it was six stories high. The windows were protected by iron shutters on Cecil Avenue and private alley. The contents of the building were a general line ot wholesale groceries. Mid. particularly, large quantities of oil. sugar, molasses, lard, hams. etc.. all. of course, exceedingly inflammable material-. The building and its contents were completely destroyed, only a few fragment of the outer walls remaining standing. The Home drv-irood- -'ore was of modern steel skeleton 164 THE PLANNING AND CONSTRUCTION OF FIO. 2. PLAN OF THIRD FLOOR OF HORNE STORE, SHOWINQ NATURE OF STEEL FRAMING. FIG. 79. PLAN OK THIRD FLOOR OK HORNE STORE, SHOWING NATURE, OK STKKL FRAMING. HIGH OFFICE-BUILDINGS. 165 construction, size 177 ft. 2 in. by 118 ft. 2J in., the walls of each floor being carried by the steel frame. It had six stories, a basement and an attic, and its front elevation stood i 10, feet high from the sidewalk to top of cornice. Transversely each floor was divided into five panels by four longitudinal rows of six columns each. At each floor the columns were connected longitudinally by steel girders, which carried the 1 5-inch I-beam floor-stringers spaced 4 feet i i { inches apart, centre to centre. Fig. 79 is a plan of the third floor. All the steelwork was protected by a nreproofing of hard clay tile, the floor-arches being 9 inches dee]) and sprung be- tween rising skews, as shown by Fig. 80. On top of the tile Fir,. So. HARD-TILE FI.OOK-AKCH CONSTRTCTION, HORNE STORK. arches was a sleeper-fill of 3 inches of concrete. The arches were of the side-construction type. The column and beam flange protection was also hard clay tile, and its general nature is pretty clearly shown by the view. Fig. heet iron. Fach floor was open throughout, and the light and elevator shafts and the stairway were open into each floor. The front and west sides of the building had very large window-areas, as shown in Fig. 82. 'I he windows were not protected in any way from exposure to tire. Fx- tending transversely across the building on the first story and between the rear wall and the sixth transverse row of columns was a balconv. 166 THE PLANNING AND CONSTRUCTION OF EFFECTS OF THE FIRE. Fig. 81 is a view of the first floor looking toward the southeast corner and showing the wreck of the elevator-shaft framing, the first-floor columns and the second-floor beams and girders, and gives a general idea of the character of the damage done. In most cases the tile on the columns was broken, leav- ing them bare in part. In the sixth transverse row of col- umns, where the flames from the burning balcony struck them, the tile for 3 to 5 feet was invariably injured, some- times entirely stripped from the metal. The greatest dam- age was done to the columns on the east side of the build- ing. Apparently the lire was most intense on this side, from other evidence given farther on as well as from this showing; but there also remains to be considered the effect which the falling water-tank may have had to displace the tile. Turning now to the floor-arches, the examination of the ruins showed that between the first and second floors the arches in panels I and II were in place and apparently capa- ble of bearing a very good load, but the bottom flanges of the arch tiles were broken here and there pretty uniformly over the whole area. The bottom flanges of the girders and stringers also showed bare in numerous places. In panels IV and Y nearly all of the arches were totally destroyed. ( )n this side of the building were the elevators, and all of the elevator-shaft framing and several of the connecting floor- stringers were torn out by the fall of the water-tank, and the debris remained on the first floor, as shown by Fig. 81. The shaded area shown on Fig. 79 indicates the boundaries within which the fall of the tank took out or bent and twisted the floor-framing. The damage was not alike on all floors, the fifth and sixth showing the worst effects, but it appeared doubtful if much of the girder-work within the shaded area could be saved. On the floors above the second the con- HIGH OFFICE-BUILDINGS. 169 dition of the arches varied but little from that already described, but if anything" was somewhat better. It was noticeable that little destruction of the T-iron and book-tile ceiling- was caused by the fire, although, of course, the fall of the tank had torn a large hole through the ceilings and dislodged many of the adjacent tile. The condition of the concrete sleeper-fill was not easy to ascertain, owing to the foot or more of debris covering it, but it was noticed that the sleepers had been burned out nearly clean wherever a place could be cleared, and also that the concrete was pretty well disintegrated. It should be stated, however, that this examination was not carried very far, owing to its difficult}' and also to the fact that a part of one of the arches under study dropped out, leaving a yawning hole at the feet of the examiner, who immediately sought safer though possibly less profitable fields of investigation. Among the more special structural damages to the build- ing were the bulging out of the east wall near the top, the peeling away from the girders of the terra-cotta front in places, and the very bad splintering and spalling off of the stone entrances and trimmings on the first-story fronts. A particularly notable feature was the action of the wood and sheet-iron shutters protecting the rear windows. Except where they had obviously been opened after the fire only one of these shutters was found open, although all were badly warped by the heat. An examination ot such as were acces- sible showed either the sheet-iron covering intact or else the inside covering burned away and the wood charred partly through, but the outside sheeting unbroken. I'nless all evi- dence fails, the volume of flame which passed through these shutters must have been confined to such as burst through the crevices due to the warping. As already noted, this rear wall was the boundary of the progress of the fire northward. I/O THE PLANNING AND CONSTRUCTION OF PROGRESS AND INTENSITY OF THE FIRE. The testimony of eye-witnesses and the logic of conditions are about all the evidences available to show the progress of the fire in the building. The fire was communicated from the Jenkins Building across the street and about 65 feet away, and it en- tered through the windows of the south front, probably being most intense at the southeast corner. It appears to have caught on all six floors at about the same time, and the flames poured up through the centre light-area and the ele- vator-shaft as through chimneys. There being no parti- tions, the flames also had full sweep along each floor. As indicating the intensity of the heat, the debris found in the building furnishes approximate evidence. Practical! v all of the combustible contents were burned to ashes, although occasional bits of cloth in the centre of large rolls and at the very rear of the building the inner leaves of books were found only partly destroyed. On the other hand a number of cast-iron standards for the counter-stools were found partlv burned or melted awav, while the crockery and glass- ware on the fifth and sixth floors had fused together into a mass. The frames of bicycles were twisted into knots, and the saddles, rims, and other combustible parts were entirelv gone. ESTIMATE OF THE SALVAGE. Probablv So per cent of the steelwork and a considerable part of the outside walls can be saved intact and used as a basis upon which to con- struct a new building. It would seem that hardlv any of the fireproofing could be lett standing; tor while portions of it may be serviceable, they are so scattered that it will be less expensive to fireproof the steel entirely anew. The Home store-building was designed bv the late \V. S. Eraser, architect, of Pittsburg, Pa., and erected by A. and S. XYilson. of the same citv. The contractor for tire steelwork HIGH OFFICE-BUILDINGS. 1/3 was the Carnegie Steel Company, and for the tireproofing the Pittsbtirg Terra Cotta Lumber Company. The build- ing was erected in 1894 at a cost, it is stated, of $700,000. FIRE IN THE HORNE OFFICE-BUILDING. This building; o was erected about the same time as the store-building ad- jacent, and the steel framework is almost identically of the same design, viz., Z-bar and plate columns, built-up Moor- girders, and 15-inch I-beam stringers. The fireproofing was of porous terra-cotta tile, the floor-arches being 9 inches thick and sprung from rising skews. A 3-inch concrete sleeper-fill covered the tile. The end type of floor-arch con- struction was used, the spans of the arches being 4 feet iij inches. The rear wall and one side wall of the building were party-walls and had no windows, but the front wall and Cecil Avenue side had windows, as shown by Fig. 8j. On each floor the building was divided into offices by 4-inch porous- tile partitions, and at the rear were the elevator-shaft and stairway. The features of construction chiefly notable in comparison with the construction of the Home store are the use of porous terra-cotta instead of hard tile, and the end sys- tem of arch construction instead of the side system. The fire was communicated from the Jenkins Building across the street, and it completely cleaned the combustible materials from ever}' floor. The fireproofing was less dam- aged near the front of the building, both the floor-arches and partitions standing quite well, as shown by Fig. 8j. Toward the rear the damage was severe, as shown by Fig. 83, show- ing the remains of a number of the 4-inch tile partitions. The first-floor rooms, which were used for stores, were open clear to the rear of the building, and there was considerable evidence to show that the flames had passed along these rooms and thence up the elevator-shaft and stairway to the rear of the floors above. On the whole the heat appeared 1/4 THE PLANNING AND CONSTRUCTION OF to have been slightly less intense in this building than in the neighboring store, although there was probably not such a great difference. A very considerable part of the fireproof- ing can be used again, and the walls and steelwork are in much better shape than in the store-building adjacent. FIRE IN THE METHODIST BOOK BUILDING. This build- ing is on the east side of Cecil Avenue and is separated from it by a car-barn one story high and about 20 feet wide. Its total distance from the Jenkins Building is approximately 45 feet. The building is rectangular in plan, with its Penn Avenue front and Cecil Avenue side divided into offices, which are separated from each other and from the hall, stair- way, and elevator-shaft by metal-lath and wooden-stud par- titions. The floors are concrete arches constructed as shown by Fig. 84. the span being 16 feet and the thickness of the arch 6 inches, with a 2-inch sleeper-fill. The concrete was composed of i part Portland cement, 3] parts sand, and o parts blast-furnace slag. The bottom Manges of the beams were haunched around and wrapped with expanded metal. The fire was communicated from the Jenkins Building and entered the windows of the offices located on the Cecil Avenue side. The most of the damage was done above the fourth floor and in the offices located about midway of the exposed side, neither the rear nor the front offices being so badly injured. In the rooms showing the most intense fire the office furniture and contents were entirely destroyed. On the sixth, seventh, and eighth floors, where the damage was greatest, the metal-lath and wooden-stud partitions were burned through between different offices and between the offices and hallway, the doors and door-frames were gone, and the woodwork mostly destroyed. Owing to the fact that there was but little to burn in the hall no great damage was done: but if the conditions had been different the fire HIGH OFFICE-BUILDINGS. 177 could easily have been communicated through the breaks in the partitions. The floor-arches were denuded of plaster, leaving the concrete bare. To the structural body of the arches little damage seemed to have been done, although one or two arches showed a slight deflection. In adjusting the insurance two of these deflected arches were condemned. The general appearance of the partitions and floor-arches in one of the offices is shown by Fig. 85. which is a fairly representative example of the conditions found elsewhere. The opinions of observers differed as to. the comparative in- tensity of the fire in this and in the Home store and office Expanded Metal Fu;. 84. CONCRETE FLOOR-ARCH CONSTRUCTION, METHODIST BOOK Hm. DING. buildings, but the evidence of the ruins indicates that the Home buildings suffered from the greatest heat. As regards other adjacent buildings there is little of in- terest as relates to fireproofing. It may be noted, how- ever, that at the rear of the Home store the Spear Plow \Yorks Building, containing large amounts of lumber, was located, while to the east of the Methodist Book Building was the Duquesne Theatre. The passage of the flames into cither of these buildings, besides destroying them, would have opened to the progress of the fire a large number of small stores and dwellings utterly incapable of affording re- sistance to the conflagration. The two fire-proof structures. however, protected the plow-works and the theatre from any serious damage, and. as already stated, were the boundaries of the fire in these directions. In the opposite direction 178 THE PLANNING AA'D CONSTRUCTION OF Fifth and Liberty streets were the boundaries. The total property loss from the conflagration is estimated at $3,000,- ooo, of which the loss on the Jenkins and Home buildings constitutes the bulk. The above gives the story of the fire with sufficient detail for a fair comprehension of what actually took place. It will not do to arraign modern fire-proof construction on the evidence here presented. The Home dry-goods store and the Home office-building were, with their plate-glass fronts, evidently too open to attack from the outside, and were in- vaded. A large stock of inflammable goods scattered over a large floor-area, with a light-shaft offering access from floor to floor, rendered the building, whatever its construc- tion, especially vulnerable. The following careful review of the subject by the editor of the Engineering Xeics presents very clearly the lesson of the lire. Tin-: ENGINEERING NEWS REVIEWS THE PITTSBURG FIRE. Considering the evidence in its general aspects first, several facts of broad significance attract attention. The lapid progress and intensity of the fire are especially evident. The reasons for this are not far to seek, being evidently the presence of vast quantities of inflammable materials upon which the flames could feed and the open exposure of these combustibles to easy ignition, especially in the Home store and office buildings. Indeed, there seems to be some irony in calling buildings fire-proof which oppose hardly anything to a fire from across the street more sturdy than plate glass. In the Home store, too. after the flames had gained access through the open front, there were no dividing partitions to delay their progress, and even the different floors were open to each other by a large light-shaft and several smaller verti- cal openings. Indeed, the conditions in this structure could hardly have been more favorable for the rapi spread of the HIGH OFFICE-BUILDINGS. l8l flames. Given such conditions it is obviously only a ques- tion of sufficient fuel to feed it for a lire to destroy any fire- proofing. Turning now to the adjacent office-building, it will be noticed at once that the provisions against the spread of tire were somewhat better than in the store building. The front exposed to the fire was fully as weak, it is true, but there were dividing partitions both transversely and longitudinally above the first floor, although not very strong ones, and fewer and smaller vertical openings. It is reasonable to as- sume that these facts account in some measure for the better condition of the fireproofing, although doubtless the smaller stock of combustibles and possibly the use of porous tile and the end construction of the floor-arches also contributed to the more favorable result. Another fact which is of interest in connection with the fire in this building is that the rlames appear to have passed along the first floor, which was open to the rear, and then to have ascended the elevator-shaft and the stairway to the rear rooms of the floors above. The building was thus attacked by the flames nearly simultane- ously in the front and in the rear. A LESSON TO BE LEARNED BY THE PITTSBURG FIRE. Before proceeding further it is well to consider for a moment what the lesson is that is taught by the general facts previ- ously outlined. It seems to us to be simply that the protection of buildings against fire does not stop with the rearing of a steel skeleton and clothing it with an integument of incom- bustible and non-conducting material: but includes imper- vious outer walls, with a minimum of window and door areas, and these protected by fire-proof shutters, frequent dividing-walls and enclosed elevator-shafts, stairways, and similar vertical openings. A provision for fighting lire is also an important consideration, although in a fire like the 1 82 THE PLANNING AND CONSTRUCTION OF one under consideration, occurring in the night and spread- ing so rapidly as it did, there is very little opportunity to use the ordinary building-hose and hand-grenades. A second fact of prime significance in connection with the fire as a whole is that the three fire-proof buildings, namely, the two Home buildings and the [Methodist Book Building, established the boundaries to the progress of the flame in two directions. In this respect, at least, they proved of inestimable value, since if the fire had once passed them it would have had a fertile field of small buildings filled with lumber and combustible merchandise to feed upon. The question may with reason be asked here: why. if these build- ings furnished so little opposition to the flames at their fronts, did they so efficiently restrict their passage at the rear ? The answer to this question is evidently found in the fact that in the [Methodist Book Building and the Home office-building the rear walls were of brick and without win- dows, while in the Home store-building the rear wall had a small window-area as compared with the front, and all win- dows were closed with fire-proof shutters. It seems the irou\" of fate, almost, that these very shutters which had been built to protect the store-building from its apparently more dangerous neighbor should have served at their first trial the opposite purpose of saving that neighbor from destruc- tion. But, not to stray too far from the main thought, let us see just what the efficiency of these protections proved to be. As already noted, the fire did not pass to the building ad- iacent to the windows covered by them. Further than this. investigation showed that while the window-framing and the merchandise adjacent to it were in ashes, none of the shutters had been burnt through. Only one shutter was seen which seemed to have been burst open by the fire or the attack of HIGH OFFICE-BUILDINGS. 183 the firemen upon it. although all were more or less warped. The heat to which these shutters were subjected, however, must have been very intense, for only a few feet from them were found masses of half-melted crockery and glass-ware and the distorted tubing of bicycle-frames. These tests were certainly crucial ones, and that they were so successfully withstood speaks stoutly for the value of tire-proof shutters. Unfortunately, this favorable evidence cannot be supple- mented by any very reliable records of the action of the shut- ters on the Cecil Avenue side of the Jenkins Building, as this wall fell early in the conflagration, and only the evidence of more or less unreliable eye-witnesses of the lire is available for consideration. According to one report in a local news- paper these shutters held until heated to a white heat and did not permit the flames to pass, but how much longer they re- mained effective is nowhere stated. It is a fact, however, that the Methodist Book Building directly opposite these windows was the last of the larger buildings to take tire, but this was doubtless due to a considerable extent to its smaller exposure of window-area, so that the existence of shutters on the Jenkins Building cannot be positively asserted to have been the cause of its later ignition. The evidence, we think, may be pretty justly summarized by stating that nothing can be said unfavorable to the efficiency of these shutters, while a good deal can be said in their favor. Passing to a consideration of the damage done by the tire to the more purely structural features of the several build- ings, one is impressed at once with the splendid showing made by the steel frames. Xot a single steel member can be said to have been torn from its position in the structure by the heat of the tire or the destruction of its protecting fire- proofing. In the Home store-building at least 50 per cent of the columns and floor-beams were found partly or wholly 184 THE PLANNING AND CONSTRUCTION OF uncovered, but only slight bends were found in two or three columns. The thing responsible for the damage to most of the injured steelwork in this building was the fall of the heavy steel water-tank from the roof, and this accident seems to have been due to the reprehensible construction of the tank-supports on the roof, which were of wood that burned away and allowed the tank to crush onto the light roof-framing. The steelwork in the Home office-building showed no injury except for occasional bent floor-stringers, and that in the Methodist Book Building did not seem to be injured at all. These facts appear to us to be very significant. Much has been said at one time and another regarding the horrible distortion which might be expected should one of our mod- ern steel skeleton structures be subjected to an extensive fire, and it is very gratifying to have these assurances refuted by practical test, if only to the extent afforded by the Pitts- burg fire. It will probably be contended by no one that ex- pansion and contraction did not occur, perhaps to a greater extent than the uncovered framework indicates, but it can be asserted that the danger of wholesale destruction from this cause does not seem to be very great. Despite all this. however, it must be borne in mind that these Pittsburg structures had large lateral dimensions and no very great height in comparison, and also that a very high character of steel construction was used. A similar fire in some of our chimney-like metropolitan office-buildings might mean a far different result. When we turn to the action of the fireproofing protect- ing the steel we find the results of the fire somewhat more difficult to analyze. In each of the three buildings a differ- ent kind of fireproofing material was used, and in each the intensity and progress of the fire itself varied. It is hardly HIGH OFFICE-BUILDINGS, 185 fair, therefore, to assume from the appearance of the ruins alone any special excellence for any one kind of fireproofing as compared with the other. There is no very good reason to doubt, however, that the heat was most intense in the Home store-building, less severe in the Home office-build- ing, and least trying of all in the Methodist Book Building. The damage to the fireproofing in these three buildings ranks in severity about in the same order. Between the Home store and office buildings the difference in the inten- sity of the fire was the least, undoubtedly, and it may be rea- sonably assumed that the better action of the fireproofing in the office-building was due to some extent to the use of the porous tile and the end construction of the arches. This rather upholds the very general opinion that the porous tile and the end construction is superior to hard tile and side construction. A particular feature to be remarked is that no particular part of the fireproofing seemed to resist the fire better than another; the column tile, the floor-arches, and the beam flange covering seeming to have been destroyed about equally. In the office-building where partitions were used, their destruction was pretty serious, as might have been ex- pected. Xo very great stability against fire and streams of water can be expected from partitions of 4-inch tile, and the wonder is that they stood as well as they did. In respect to their efficiency, however, there does not seem to be much choice between partitions of 4-inch tile and metal-lath and wooden-stud partitions used in the Methodist Book Build- ing, and the builder who pins his faith to either to resist a severe attack of fire and water is likely to be disappointed. The behavior of the i6-foot-span concrete floor-arches in the Methodist Book Building must, we believe, be con- ceded bv everv fair-minded man to have been most excel- 1 86 THE PLANNING AND CONSTRUCTION OF lent and to justify the faith which many architects and en- gineers have shown in concrete floor constructions. It is true that the heat to which they were exposed was not as great as that in the buildings with the tile construction, but it is also true that many of these concrete arches were in the midst of a very severe fire for a considerable time, and came through it, with hardly any exception, absolutely unharmed. AYe believe that the Pittsburg fire adds convincing evidence to that already accumulated in engineering literature that concrete is entitled to rank as a material of the highest value in fire-proof construction. In what has preceded will be found some of the sugges- tions which the fire at Pittsburg seems to offer to architects and engineers, and doubtless others will be found in study- ing the story of the disaster. To such experts we may con- fidently entrust the evidence given for a fair consideration, but the general public will hardly lay so much stress on these finer points, and will want an unqualified answer to the ques- tion whether the Pittsburg fire did or did not prove the use- lessness of fire-proof construction. It may be answered at once that it proved the value of such construction, if for no other reason than that these fire-proof buildings prevented the spread of fire beyond them. It is true that the business man may see little inducement to fire-proof construction if it means loss on the fire-proof building and safety beyond it. but he can also see that if the fronts of these burned buildings had been as well protected as their rears the fire would have serious difficulty in ever entering them. Just here is the thing that the average builder has been prone to overlook. I le will go to great expense to make his building incombustible, and then, for reasons of economy, or to dis- play his goods, or to gain some other end which he desires, he will stop short of making it reasonably inaccessible to fire. HIGH OFFICE-BUILDINGS. I 8/ The three fire-proof buildings at Pittsburg were destroyed by an exposure fire, and they could have been hardly more open to the access of such a fire if their whole fronts had been lacking. \\'e are not overlooking the fact that buildings must be suitable for occupation and business and, therefore, must have doors and windows and stairways, but these can all be had and the openings still be protected in such a manner as not to afford free access to flames and heat. For example: there was no structural reason why the windows of the Home store and office buildings at Pittsburg should not have had rolling steel shutters ; and if they had, is there much question but that the firemen from inside these build- ings could have saved both from serious damage? It is need- less to go further into the consideration of what might have been done, for enough has been suggested, we think, to show that an}- wholesale condemnation of tire-proof construction, when we consider it in its broad meaning of protective con- struction against the spread of flame, is not warranted by the 1) ittsburg fire and its results. hi a closing word attention may be called to the fact that modern fireproofing systems have never before been sub- jected to so severe a test as in the Pittsburg fire, nor has it ever before suffered such wholesale destruction bv fire. 1 88 THE PLANNING AND CONSTRUCTION OF CHAPTER VI. COLUMNS. OF the three elements which enter into the construction of great office-buildings of the skeleton frame foundations, columns, and floors the question of proper column ar- rangement and column construction we believe to be the most important. Foundations may sink or settle in place, and cause derangement in the levels and the buildings to lean out of plumb; the floors may bend or break and arches may fall; but if the columns should fail there is danger that the entire structure will collapse. ARRANGEMENT OF COLUMNS ON FLOOR-PLAN. The ar- rangement of the columns, like the floor beams and girders, should be such that the material will be used in the most economical manner, and, if it is intended that the building shall be divided into a fixed number of offices with a certain width to each, it will be necessary to place the columns at the junction of these offices and partitions, spacing the beam:; and girders accordingly, and using such section of material as will be justifiable in the sense of economy. To reduce the weight of the load of the superstructure upon the party-line walls it often becomes necessary to place the second row of columns closer to that line, avoiding as much as possible great eccentric loads upon the foundations. The sixty-two columns in the Central Bank Building are arranged in such a manner that the loads upon the same are almost identical, excepting those facing the front walls which HIGH OFFICE-BUILDINGS. 189 support the masonry walls. This system causes an equal distribution of the loads upon the entire foundation, and an equal settlement of the whole building is assured. SKELETON COLUMNS SEPARATED FROM OUTSIDE WALLS. In the St. Paul Building Mr. Geo. B. Post made a form of construction similar to that used in the Havemeyer Build- ing, described in the writer's book on " Skeleton Construc- tion in Buildings," with this difference, that the Havemeyer Building has self-supporting walls, and the St. Paul Building walls are constructed as shown by the illustration. Fig. 8n. All columns are made in two-story lengths, web-spliced about two feet above the floor-beam connection. The floor- girders are made double, one piece fastened to each of the opposite sides of the column by web-brackets so as to balance the loads, and are continued beyond, almost to the face of the buttresses, so as to form cantilevers that carry the masonry in one-story spandrels. Fxterior plate and angle-gusset knee-braces are riveted to the column above and below the girder in the thickness of the buttresses, so as to make rigid sway-bracing', and wall- girders are connected to the web of the cantilever, a wider base being provided for the buttress piers by the insertion of horizontal plates on the top of the cantilevers and wall- beams, and stiffened by angle-brackets at the corners. All the outer wall columns are located entirely within the interior face of brickwork, and thus stand out freely in the rooms, their outer flange being at least 10 inches from the outside face of masonrv. Then around the column is built a casing of porous terra-cotta, which makes an insulating lire-protec- tion and forms two air-spaces. Being separated from the walls, this terra-cotta can be quickly and easily removed to permit inspection or repairs. The column is further protected by a >heet of asphalted 1 90 THE PLANNING AND CONSTRUCTION OF felt, forming a damp-proof course on the outside next the brickwork. A space is left between the brickwork and as- phalt sheet, which is finally filled in solidly with grout. FIG. 86. The special features Mr. Post claims for this method of construction are more effectual exclusion of moisture and HIGH OFFICE-BUILDINGS. 19! prevention of corrosion, superior fi reproofing, and a connec- tion of the floor-system so as to avoid eccentric loading of columns. CAST-IRON COLUMNS. Cast-iron columns for high- building construction still have their adherents, but the writer recommends them only for those buildings with large bases and ten stories or less in height; and, if so used, extra- ordinary care should be taken in their manufacture, in the nature of the joints, and in the construction. Of the several forms of castings used the following illus- trations show some of the sections (Figs. 87 and 88). The Oil Fn;. >;. Fie;. 88. circular and square columns possess more merit than the other shapes; the square section can be built into the walls with more facility than the circular, the latter section being used principally for the interior of the building. The forms shown by Fig. 88 are identical, with the exception that the web of one has open spaces in various points in the height. These two sections admit of measuring and inspecting the thickness of the castings at all points; but the irregular rates of cooling caused by the open spaces are without doubt preju- dicial, and it is preferable to have the webs continuous. \\ e have seen such columns crack by being simply unloaded from the hauling trucks. The vertical sections of all these cast-iron columns are joined together by means of flanges, and the beams to them by lugs, resting upon brackets, as shown by the illustration. Fig. 8(). The ends of the sections must be carefully machine- faced, at true right angles to the axis of the column. Fven 192 THE PLANNING AND CONSTRUCTION OF if this is carefully done, in setting the work at the building it very frequently happens that shimming has to he exten- sively practised, and the full hearing of the column becomes questionable: and too often, when the column receives its full load, the Manges are snapped from the shaft, and a bolted cast-iron flange-joint for a column is thus made worse by such methods. The number and size of bolts at each joint vary from three-fourths to one inch, placed about six inches tj f! +J apart. To add additional strength to these llanges small brackets are cast with the column at various points, where they do not interfere with the bolting. The ends of the beams and girders are commonly sup- ported upon the column by brackets and lugs, as shown. If it becomes necessary to use cast-iron columns in these structures, \ve recommend omitting lugs and joining the beams to the columns by drilling holes through the shaft, using short, heavy bolts, and. in the case of opposite beams, long bolts to reach through. STEEL COLUMNS. Columns made of rolled-iron shapes have, on account of expense in manufacture, gone out of use, HIGH OFFICE-BUILDINGS. 193 and steel columns have taken their place, the commercial shapes of which are shown in the following plate. Fig. 90 is a section made of four angles and a plate with two lines of riveting, the lower section of the same figure having an additional area added to it by the two plates, which are riv- eted to each of the angles by two lines of riveting. This sec- Oil oil 01 c (.. 1 o o o ~ c c o o o o _JL_ TT JL FIG. 90. J TT _TL ;. 93. tion, without the outside plates, is no doubt the simplest and least expensive to use. Then we have another inexpensive column in that shown by the lower section of Fig. gi. a box column made of chan- nels and two cover-plates with four lines of riveting. The upper section of the same figure is a box column, but com- posed of plates and angles requiring eight lines of riveting. 194 THE PLANNING AND CONSTRUCTION OF These sections are often constructed as shown in Fig. 92, using latticing. Another column which has been used extensively throughout the country is that shown by Fig. 93. the upper section having two lines of riveting and the lower six lines. The Z-bar column, so called from its shape, has been more extensively used in the West, especially in the tall buildings erected in Chicago. The usual connection of one column to another, too often adopted in the West, is not recommended by the writer, as beams and girders resting upon plates, with no other connection except bolts or rivets through the rlanges, are not, in his opinion, suitable for high or even low buildings. In the lower stories of tall buildings, where the loads are exceedingly great, these Z-bar column sections can be ma- terially increased by the addition of cover-plates, as shown. t"p to the present the above forms of column sections have been more extensively used than any other; but a few patented shapes have come into existence since 1890, one of which is the " Larimer Column," made by bending two I beams at right angles in the middle of the web and riveting them together: another is the " Clray Column." made up of angle-bars, as shown by the illustrations, riveted together in pairs, and braced about every two feet in length by tie-plates, usually eight or nine inches wide, riveted to the angles as shown. The latter column has special advantages which the others have not: the material is so disposed as to be as far as possible from the neutral axis of the cross-section: then, again, angle shapes are quite common, and extensively used and manufactured. FtKKPRooFixr, COLTMXS. The incipient stages of a fire, where there is so little to burn in a large building, would probably do little damage to the construction: but in many HIGH OU. '95 SQUARE COLUMNS. PLAN OF COLUMN SHOWING METHOD OF INCREASING SECTIONAL AREA. 30-INCH COLUMN. FIG. 94 Tut; GRAY COLTMN. 196 THE PLANNING AND CONSTRUCTION OF BRACKET CONNECTIONS. CONNECTION FOR 12-INCH BEAM. CONNECTION FOR 15-INCH BEAM. ) i o : o > 9 ; 9 < i 1 "6" :" ~ i 1 | 9 > < > 3 o o ar 9 i < J I I ! > ( a 1 3, o 9 d r CONNECTION FOR PLATE GIRDERS COLUMN SPLICE. ECCENTRIC CONNECTION FOR 12-INCH REAM. FIG. 95. THK GRAY COLUMN. HIGH LJ-'FICE-BI'ILDINGS. 1 97 cases great heat can be generated in a very short time with the contents of a room, and when a flood of cold water reaches the metal in the column it is not difficult to realize the result. All the column sections shown in the illustrations can he made practically fire-proof in various ways. The Xew York law provides for fireproofing a column where it supports a solid masonry pier by covering the supporting shaft with an outer shell and filling' in the open space between with a non- combustible material. The covering of columns is required by the Chicago law to be as follows : " if of brick, not less than 8 inches thick ; if of hollow tile, one covering at least _'.] inches thick. If of fire-proof covering, it shall be at least 2 inches thick. Whether hollow tile or porous terra-cotta is used, the courses shall be so anchored and bonded together as to form an independent and stable structure." " In all cases there shall be on the outside of the tiles a covering of plastering with Portland cement, or of other mortar of equal hardness and efficiency when set. " " If plastering on metallic laths be used as fireproofing for columns, it shall be in two layers, of which the first shall be applied in such a manner that the mortar will cover the entire external surface of the column, while the space be- tween the two layers shall not be less than I inch thick." ' The metallic lath shall in each case be fastened to me- tallic furring, and the plastering upon the same shall be made with cement. Protection for the lower five feet shall be re- quired in this case the same as where porous terra-cotta or hollow-tile covering is used." The Xew York law further states that " where columns arc used to support iron or steel girders carrying curtain- walls, the said columns shall be of cast iron, wrought iron. IQ 5 THE PLANNING AND CONSTRUCTION OF or rolled steel, and on their exposed outer and inner surfaces shall be constructed to resist lire by having a casing of brick- work not less than 4 inches in thickness and bonded into the brickwork of the curtain-walls." \Ye believe that the columns shown in the figure, where it is separated from the outside wall, is the most effective; but in many cases we have used a four-inch and. eight-inch brick covering, setting the work with Portland cement, and in many cases porous terra-cotta tile with hollow spaces, also set in Portland cement. The use of brick is probably the cheapest method, as it can be accomplished during the building of the walls of the structure. The principal requirement governing such fireproofing is that the material shall be non-heat-conducting. BEARING STRENGTH OF COLUMNS ACCORDING TO THE NEW YORK BUILDING LAW. Section 483. Every column, post, or other vertical support shall be of sufficient strength to bear safely the weight of the portion of each and every floor depending upon it for support, in addition to the weight which the floors support. The dimensions of each piece or combination of materials required shall be ascer- tained by computation, according to the rules given in Has- weli's " Mechanic's and Engineer's Pocketbook." except as may otherwise be provided for in this title. CRUSHING \YKIGIIT OF METAL IN COLUMNS XEW YORK BUILDING LAW. The strength of all columns and posts shall be computed according to Gordon's formuke. and the crushing weight in pounds per square inch of section shall be taken as coefficients in said formula-, namely, cast iron. 80.000; wrought or rolled iron. 40,000; rolled steel, 48,000. HIGH OFFICE-BUILDINGS. 99 COLUMNS IN FIRE-PROOF BUILDINGS NEW YORK BUILDING LAW. Section 484. All cast-iron, wrought-iron, or rolled-steel columns shall be made true and smooth at both ends, and shall rest on iron or steel bed-plates and have iron or steel cap-plates, which shall also be made true. Section 4^5. In all building's hereafter erected or altered, where any iron or steel column or columns are used to support a wall or part thereof, whether the same be an ex- terior or interior wall, excepting a wall fronting on a street, and columns located below the level of the sidewalk which are used to support exterior walls or arches over vaults, the said columns shall be either constructed double, that is, an outer and inner column, the inner columns alone to be of sufficient strength to sustain safely the weight to be im- posed thereon, or such other iron or steel columns of suf- cient strength and so constructed as to secure resistance to fire may be used, as may be approved by the superintendent of buildings. Iron posts in front of party-walls shall be filled up solid with masonry, and made perfectly tight between the posts and walls to prevent effectually the passage of smoke or tire. Cast-iron posts or columns which are to be used for the support of wooden or iron girders or brick walls, not cast with one open side or back before being set in place, shall have a three-eighths of an inch hole drilled in the shaft of each post or column by the manufacturer or contractor fur- nishing the same, to exhibit the thickness of the castings; and any other similar-eyed hole or holes which the superinten- dent of buildings, or his duly authorized representative, may require shall be drilled in the said posts or columns by the said manufacturer or contractor at his own expense. Iron posts or columns cast with one or more sides and backs shall have solid iron plates on top of each to prevent 2OO THE PLANNING Ai\'D CONSTRUCTION OF the passage of smoke or fire through them from one story to another, excepting where pierced for the passage of pipes. No cast-iron post or column shall be used in any building of a less average thickness of shaft than three quarters of an inch, nor shall it have an unsupported length of more than twenty times its least lateral dimensions or diameter. No wrought-iron or rolled-steel column shall have an unsupported length of more than thirty times its least lateral dimension or diameter, nor shall its metal be less than one fourth of an inch in thickness. All cast-iron, wrought-iron, and steel columns shall have their bearings faced smooth and at right angles to the axis of the column; and when one column rests upon another column they shall be securely bolted together. COLUMNS FOR CURTAIN-WALLS. Where columns are used to support iron or steel girders carrying curtain-walls, the said columns shall be of cast iron, wrought iron. or rolled steel, and on their exposed outer and inner surfaces be constructed to resist fire by having a casing of brickwork not less than four inches in thickness and bonded into the brickwork of the curtain-walls, or the inside surfaces of the said columns may be covered with an outer shell of iron hav- ing an air-space between: and the exposed sides of the iron or steel girders shall be similarly covered in and tied and bonded. STRENGTH OF COLUMNS I'UFFALO I'UILDINI; LAW. (Section 146.) Cast-iron Columns. Cast iron subjected to crushing strain only, as in bearing plate, may be loaded to the ex- tent of 15.000 pounds per square inch. Compression strain on cast iron shall not exceed 13,000 pounds per square inch. Tensile strength on cast iron shall not exceed 3000 pounds per square inch. HIGH OFFICE-BUILDINGS. 2OI Cast-iron Pillar FormuUc. L* \ Round columns, 5= 14,000^ ~ ( i - y. x 600 1)'' ' / I* \ Square columns, 5 = 14,000^ -=- I I -\ ----------- -I. * ' S safe load in pounds. L = length of column inches. D = diameter'of column in inches. Round columns, A = sectional area of column in inches. Square columns, A = side or least horizontal of any other column. Riveted Columns Wrought Iron. For riveted or other forms of wrought-iron columns more than gor in length, .S' = 10,600 30 . r For riveted or other forms of wrought-iron columns less than 9Or in length, S = 8000 30 - . Steel. For riveted or other forms of steel columns more than 90^ in length, 5 = 17, 100 $/. For riveted or other forms of steel columns less than gor in length, 5=i2, ooo ; 7 '- J/ r 202 THE PLANNING AND CONSTRUCTION OF ..S" = safe load in pounds per square inch. L = length of column in inches. / = least radius of gyration of columns in inches. STKLNGTH OF COLUMNS - CHICAGO BUILDING LAW. Cast-iron Columns. \Yhen cast iron is subjected to crush- ing stress only, as in plates, it may be loaded to the extent of 15,000 pounds per square inch. Cast-iron Pit/ar l : ormulie. For round columns, L = length of column in inches. I) = diameter of column in inches. A = sectional area in square inches. /,' For rectangular columns, i" = io,oooy/ -^- 1 i - I) = the side of the square or least horizontal dimension of other rectangular columns. Riveted Columns. For riveted or other forms of wrought- jron columns, ( I* S 12, OOOA -T- ' - j . V 36,ooor 7/ i'^^r riveted or other steel columns less than dor in lenth, (C>oL\ ( } . \ I- ' HIGH OFFICE-BUILDINGS. -OJ For riveted and other steel columns more than 6or in length, .S' = i 3,500. /. A sectional area of column in square inches. /, = length of column in inches. r -- least radius of gyration of columns in inches. RKMARKS ui-ox TIIK DIFKKRKXT FoRMn..-K AS USKD ]'<>!< Coi.r.Mxs. Steel columns fail either by deflecting bodily out of a straight line, or by the buckling up of the metal between rivets or other points of support. To guard against these two results various formuhe have been contrived, such as those quoted above from the different building laws, and other formula,- have been derived from actual tests. The tests of full-size wrought-iron columns on which the value of empirical coefficients in Gordon's formula are based are discussed in " The Elasticity and Resistance of Materials," by Mr. William II. Burr. The results of those tests yield the following formuhe for ultimate resistance: Let/" ultimate resistance in pounds per square inch; / -= length of column in inches , r -- radius of gyration of column section in inches, in which direction the failure takes place. Then /'= _4- 000 __ i 4- :O.OOO If a factor of safety of four be employed, as is usual for \vrought-iron columns in building construction, and if /' rep- resent the allowed working stress per square inch, then 1O.OOO I 2O4 THE PLANNING AND CONSTRUCTION OF The preceding formula should be used only within the limits of / 50^ and / = i^or. For any value of / less than 5Or the values of P found at that limit should constantly be used, and no columns with /greater than 130?" should ever be permitted. It is to be observed that / and r must be taken in the same unit, it being usual to take them in inches. Mr. Burr also states that the straight-line formula may be used as the one above. The notation remaining the same as before, /= 44.000 140-. If the working stress be taken at one fourth the ultimate as before, then P i 1,000 35-. The ultimate resistance or the working stress of the column will be found by multiplying the area of its cross- section in square inches by the preceding value of f or P respectively. The very simple form of straight- line formula makes it easier to use than Gordon's, and it also represents the results of tests a little more accurately. The following table, by Mr. Burr, gives the values of P, the working pressure per square inch, for both the straight- line and (iordon formula, with the values of varying from r 50 to 98. HIGH OFFICE-BUILDINGS. 2O$ I 10,000 P = 1 1, ooo 35 . / = -- r I / I _l I3,OOO r- Pounds. Founds. r 50 . 9- 2 50 9> 2 3< 54 9- 110 9^44 58 8,970 8,992 62 8,830 8,865 66 8,690 8,732 70 8,550 8,596 74 8.410 8,457 78 8,270 8,314 82 8, 130 8, 169 86 7,990 8,022 9 7,850 7,874 94 7'/!0 7>7 2 5 98 7o7 7,575 The fact that columns of different forms of cross-section, but with the same value of -, will give somewhat different r values of ultimate resistance per square inch, should not be forgotten, although that difference in the cases of good de- signing is never great. COLUMN JOINTS. The stability of the skeleton frame depends upon the proper designing of all its structural parts, especially the column joints. When the structure covers an extensive ground-area and wind-braces are not needed, we recommend the column joints shown by the detail, Fig. 96. The connection can be applied to all the steel sections herein shown. Wixn-BKAClNC,. A building whose height does not ex- ceed three times its base and which has a well-constructed frame scarcely needs a special system of wind-bracing to make 2OO THE PLANNING AND CONSTRUCTION OF it secure. The column should be in lengths of two or more stories, and thoroughly spliced at the joints with plates and Fi<;. c/>. DKTAII. OF COLUMN JOINT. resets sufficient to make the section nearly continuous .is far as the transverse bending is concerned. BKAMS AND GIKDKKS. The application of steel beams and girders to high buildings is similar in every respect to ///(;// OFF1CE-B U1LDINGS. CONNECTIONS FOR BEAMS OF DIFFERENT SIZES. 207 15' I w. STp CONN^ rH|2'I l5 pp 15' _STPC ~? % I WITH 7" I ONH. =^ oc 2A--w " 9< /to o<; ~--t" 1^ ^9 ' jsS ? 1 ? 5 T< iiJ 15 5TD< 5> ...^.. !x 8" 3TTJ CON I WITH 6" I X)NN. ="^^ IZ-5TDCOKN. 15 15" I WITH |O"I ST-D CON^ QH ?J 3 ] 23 1 pao-F^ < :S O< -O^SK8)VFOI IO--M1 '- O< oc j"3 1 1 j 12 STTH J S 1 1- ONN. ^ I5 g & ST'O CON TH |O"I psfcy /^T? J1 1 15' I wr "STO CONN. i '.' ^ O'ST'O CONN. IZ rn 9" I w fc, ,tJ * 1 * 12' 3TD C Cs _ ^ 12' 3TD C ^ ^ . S- ?' 5T ? CON sp'. PACE I WITH 9" I ANN SPL FACE. OC 9 -* oc o | >fc|j ' 10'STD CONN. i 1 I5'I WITH 8"! ST'O CONN. SPL FACE Q J3 o _^ \--*s* tf ?*' >* ? 9" 3TD CON I WITH 8" I ONN SPL FACE. =^ff g ^T. f?^l i** j^r i t- ^ 8 - STO CONN. 2 ^ ^ FIG. 97. CON SKI "i'ii KOK HKAMS or DIFFERENT SIXES. 2O8 THE PLANNING AND CONSTRUCTION OF CONNECTIONS FOR BEAMS OF DIFFERENT SIZES. IE' I WITH 7" I IZ'STD CONN. SPL.FACE 12"! WITH g- 1 12'STO CONN. SPL.FACE. |O"I WITH Q" 8' STD CONN. 8" ST CONN. 9" I WITH 8" 1 9" STD CONN. 8" STO CONN. 9"! WITH 7" 7'STD CONN. 7"ST'D CONN. 6"! 8"i WITH 7" ST'D CONN. 7'STD CONN. J'STD CCNN 7- STP CONN. fa' STD CONN. 6'.6'Lf 5' LONG. It Zi Z."-6"ST'D CONN. 7"! W.TH 6"! 6-1 V L- 4%." LONG. it <* 6' STD CONN. Fit HIGH OFFICE-BUILDINGS. 2OQ all other methods of si eel construction. The various rolling- mills have their handbooks from which the strength of any beam section from 3- to ^4-inch is given. I Seams 24. _>o, iS, and 15 inches in depth are generally used as girders, while those of u. 10, o,. and maller sections are used for framing well-holes, flues, and elevator-enclosures. \\ here rolled I beams arc not sufficiently strong for car- rying the loads, riveted girders with single webs are em- ployed. The writer has treated the subject of beams in his work on " Skeleton Constructed Building's." ;: and that of riveted girders in "Compound Riveted (iirders" for buildings, ar.d refers the reader to those books. r>K.\M COXNKCTIOXS. To get the full strength of the beams, there are needed angle-knees riveted or bolted to the ends with sufficient rivets or bolts. The illustrations Figs. <)7 and <)8 show standard connections as ordinarily used in building work. Published by |"hn Wiley n clay should be laid at such depths as to be unaffected by the weather; since clay at considerable depths will gain and lose water as the seasons change. When coarse sand or gravel is mixed with the clay, its supporting power is greatly in- creased, being greater in proportion as the quantity of these materials is greater. \Vhen they are present to such an ex- tent that the clay is sufficient to bind them together, the com- bination will bear as heavy a load as the softer rocks. FOUNDATIONS UPON GUAVKL AND SAND. Sandy soils vary from coarse gravel to fine sand, and when these are mixed they make one of the best and firmest of foundations, it is not affected by water if confined laterally, so that the sand and gravel cannot wash out. This material makes an excellent foundation-bed and is practically incompressible when under high buildings. FOUNDATIONS IN SILT. MUD. SOFT KAKTII. AND (Juiri<- SAND. Xo foundation should start upon made land, silt, mud. or quicksand. Such material should always be pene- trated to the firm soil beneath, and when made land overlies i firm earth the footings of the foundations should be carried to the natural soil. HKAKINI; POWKR OF SOILS. IVobablv the easiest method of determining the power of the foundation-bed i-- l>v 212 THE PLANNING AND CONSTRUCTION OF means of the square platform with four legs about six inches square; the load being put on gradually and frequent levels taken. One fifth to one half of the load required to produce settlement is generally adopted for the safe load. \Ye quote the following table compiled by Ira O. Baker, C.E., for his " Treatise on Masonry Construction ": TAHI.E OK THE HEARING POWER OK SOILS. Bearing Power! in 'Tons per i Square Foot. I Kind of Materials. Rock, hard 25 30 soft 5 10 Clay on thick beds, always dry 4 6 ' ' moderately dry 2 4 soft i 2 Gravel and coarse sand, well cemented S 10 Sand, compact and well cemented 4 (> " clean, dry 2 4 Quicksand, alluvial soils, etc 0.5 i The Xew York Building Law requires that " (iood solid natural earth shall be deemed to safely sustain a load of 4 tons to the superficial foot, or as otherwise determined by the Superintendent of Buildings, and the width of footing courses shall be at least sufficient to meet this requirement." The Chicago Building Law requires that " If the soil is a layer of pure clay at least 15 feet thick without admixture of foreign substance, excepting gravel, it shall not be loaded more than at the rate of 3500 pounds per square foot." " If the soil is a mixture of clay and sand it shall not be loaded more than at the rate of 3000 pounds." " If the soil is a layer of dry sand 15 feet or more in thickness and without admixture of clav, loam, or other foreign substance, it shall HIGH OFFICE-BUILDINGS. J I 3 not he loaded more than at the rate of 4000 pounds per square foot." ForXDATIOXS OF T1IK C~FXTRAL B>AXK Bl'IUMXC. The foundations of the Central Bank Building- rest upon ( ;ood, clean, sharp sand and have a total pressure of dead and partly SECTION OK FofNDATlox, CKNTRAI. HANK Hni.niM,. assumed load of 4 tons per square foot, as called for l>y the Xe\v \'ork Building Law. The partly assumed load refers to that portion of the weight relating to the li\'c load upon the floors, as mentioned in the chapter on Floor Construc- tion. It is an unknown quantity which seldom ever reaches the foundations within live per cent of its entirety. The Central Bank Buildinraced and made sufficiently strong to carry building ma- terials, and planked up to the building line, with outer edge guarded. The braces to be removed, shifted, and replaced \vhen required. " Provide a double-rail fence with steps to approaches on both sides of bridge. " Bidders must examine plans before submitting pro- posal. " Protect all subways, hydrants, lamp-posts, gas-mains, and any property belonging to the city or private corpora- tions. " Protect the owner from any suit for damages to any person or persons or to the property of any person or persons arising during the progress of and by reason of the perform- ing of the contract." PNEUMATIC CAISSONS. From the foregoing it will at once be seen that for supporting the loads the ordinary build- ing foundations present no difficulty, but for very heavy and high buildings where it is not possible to get a sufficient and satisfactory foundation upon soil and piles some other scheme has to be resorted to: hence where considerable depths are involved the pneumatic process is admirably adapted, and has been used with success in the Manhattan Life Insurance Building, the American Surety Building, the Washington Life Building, the Kmpire Building and others, all of \ew York. The pneumatic caissons for the foundation-work of build- ings are made of steel plates riveted together. The side or shell, as well as the roof, is made of thin metal, leaving the maximum amount of space to be filled with concrete or other masonry which forms the foundation. The excavation is made under or in the caisson under air-pressure sufficient to hold back anv water-bearing material which mav underlie the HIGH OFFICE-B I'll. DINGS. foundations of adjoining' buildings. The foundations arc thus easily carried down to bed-roc!: without the slightest dis- turbance of surrounding foundations. After the caisson has been sunk to its proper depth and bed-rock has been reached, the surface of the latter is care- fully prepared to receive the concrete filling of the air-cham- Fir,. TOT. SHMXVINC; MANNK.K or Kx< AVATINC CAISSONS. ber. All clay, sand, or other loose stuff, and any soft portions of the rock, are cleared off and made level. Circular or rectangular caissons are generally used, the load and spread of the foundation determining the shape. The height of the working-chamber is generally about S feet, as shown by the view. Fig. 101. section showing manner of excavating in caissons. CAISSON DKTAIL. The sectional plan and top view. Fig. 1 02. shows the general construction of a square caisson. It is 2^ ft. o in. bv ji ft. o in. bv I i ft. d in. high, and built en- 220 THE PLANNING A. YD CONSTRUCTION OF tirely of steel plates, angles, and beams. The sides are -g-in. plates and stiffened with brackets made of 6 x 6 in. steel angles, and further stiffened by /-in. steel bulbs placed hori- zontally between the brackets. In the centre of the roof a shaft 4 feet in diameter is constructed, with air-lock, for the use of men in entering and leaving the working-chamber, and also for filling the chamber after the caisson has reached rock. This caisson was used at the Manhattan Life Insur- FIG. 102. TOP VIEW OF PNEUMATIC CAISSON, MARKED "M" ON SECTION OF FOUNDATION. ance Building. Fig. 103 shows the transverse section, and the caisson marked " M " referred to above. HYDRAULIC CAISSONS. A later method of sinking foundations is that where open steel caissons are forced down by the hydraulic process. The material through which the caisson sinks is removed by forcing water under pressure ///(/// OFI-1L E-BL'lLDIi\GS. 221 through vertical pipes from the surface of the soil in the ex- cavating chamber, so as to scour out the materials. The caissons are sunk to the required depth through loose soil without the use of pneumatic pressure or the entrance of workmen into the excavating chamber, the progress being regulated and alignment maintained by turning on and off the jets in the different parts of the caisson, and by weighting it in the usual manner. MI;. 103. TKANSVKRSK SKCTION <>i- FOUNDATION, MANHATTAN I.n-i After the caisson has been sunk it is tilled with grout. etc., injected through the same tube, so as to make a solid bed. the water pumped out. and the concrete masonry tilled in to the building foundation. These open caissons are lap-jointed steel cylinders, each about h feet high, and their diameter from 4 to in feet, de- pending, as in the pneumatic process, on the size of founda- tion required. As they are simply a shield to exclude the earth and water during excavation and tilling, and bear no 222 THE PLANNING AND CO\ 7 STRL'CTION OF part of the superstructure, they are therefore made of thin steel plates -j in. to in. thick. The caissons are shod with special cutting edges of segments of hollow castings bolted to the inside of the shell. Several tall and heavy office-build- ings have had their foundations put in successfully by this process. ForxDATioxs UPON STEEL BEAMS AXD CONCRETE. Another style of foundation, composed of steel beams joined together by bolts, with the space between filled with con- crete, is frequently used under these large buildings. By this so-called " raft or grillage system," in which alternate layers of steel beams of lessening length are employed, it is practi- cable to spread the bearing to a sufficient extent to require only a minimum amount of cellar space. The peculiarity of the Chicago soil, of 12 to T; fee' of moderately firm soil overlying a much softer clay 40 to 50 feet thick, led to the adoption there of the above method under a great number of buildings, although piling is com- mon in that city. In Xew N i ork the raft method is frequently employed, bur is open to the objection that the conditions throughout the soil area are apt not to be uniform. And there is often a very serious objection that at some part, if not under the entire building, the material at certain depths mav be sandy or of the nature of quicksand, and may yield or be relieved at some future time. MAXXER OF SETTIXG STEEL BEAMS ix FOUNDATIONS. Before the beams are laid they should be cleaned thoroughly, and while absolutely dry be heated and coated with coal-tar. The beams should be set upon a bed of concrete of good thickness, certainly not less than 12 inches. Upon this con- crete the beams should be carefully bedded. The distance apart should not be greater than the height of the beams. HIGH OFFICE-BUILDINGS. 223 and they should not be set too closely together to prevent the ramming of the concrete. METHOD OF CALCULATING THE STRENGTH OF GRILLAGE BEAMS. The various rolling-mills in their handbooks give methods of calculating these beams for foundations, and we have taken the following table and calculations from the Handbook (1897) of the Passaic Rolling Mill Co. TOTAL SAKE LOAD ON A SINGLE BEAM IN TONS OK 2000 POUNDS FOR THE FOLLOWING VALUES OK L B. L = length of beam in feet; /> = length in feet over which superim- posed load is distributed. Be;un. Unloaded Length of Beam /, />' in Feet. So .-a 8 10 1 1 '3 M 15 O ''A j 20 90 115 100 89.2 80.3 73-0 66.9 61.8 57.4 5 3.6 20 80 IO2 89.6 79,8 71-7 65.2 5Q-S 55-2 51-2 47. > 2O 64 87.5 76.8 68.1 61.3 55-7 51.1 47-1 43- S 4 ( >-9 15 60 64.8 ] 56.6 50.4 45-4 41.2 37-S 34.9 32.4 30.2 If, =;0 53.8 47.0 41.8 37-7 34-2 31.4 29.0 26.9 25.1 15 41 43-7 3^-2 34- 30.6 2 7' 7 25-5 23.5 21.9 20.4 12 40 41.6 35.8 31.3 27.8 2^.0 22.7 20. S 19.2 17.9 16.7 12 32 32.6 28.0 24.5 21.8 19.6 17.8 16.3 i ?. i 14.0 13.1 ' 33 34.4 28.6 24.6 21.5 19.1 ] 7- 2 15.6 14.3 13.2 12.3 11.5 io 25 26.2 21. S 18.7 16.3 14.5 I3.I II. g 10.9 io. i 9.3 8.7 9 27 26.2 21. S ' 18.7 16.4 14.6 I3.I n.g 10.9 to. i 9.4 : 8.7 9 21 20. o 16.7 14.3 12.5 i i.i 1O.O 9.1 8-3 7.7 7.1 6.7 8 1 8 15.1 12.6 10.8 9.4 V4 7.6 6.0 f) -3 5.8 To illustrate the application of the table, take a founda- tion carrying a load of 400 tons on a soil capable of carrying 2 tons per square foot. The required area of the footing will be 200 square feet. If a square footing is used, a square with i-j-ft. sides has an area of 196 square feet, and will be assumed as ample. The upper layer of beams will be proportioned first. The base-plate resting upon the upper layer will be 224 THE PLANNING AND CONSTRUCTION OF assumed as 4 feet square; then in this case R is 4 ft., L is 14 ft., and L B 10 ft. The upper layers will be assumed to con- sist of five beams, as this number is the greatest that will pro- vide sufficient space between the flanges of the beams to per- mit satisfactory ramming of the concrete filling. Each beam will take one fifth of the total load, or 80 tons. By referring Ki<;. 104. STEKL-HEAM SECTION OK GKILLA<;K FOUNDATION. to the table, a 20-111. (jo-lb. beam has a safe load of 80.30 tons when L B is 10 ft. The upper layer will therefore consist of five 2O-in. 90-!!). I beams. In the under layer, in this instance, L and B have the same value as the upper layer. If the beams are spaced about 12 in. on centres, there will be fifteen beams in the layer, each carry- ing one fifth of the total load, or 26?, tons. The lightest beam by the table is a 15-in. 42-!!)., which has a safe load of 30.6 tons. A less number of beams can therefore be used. HIGH OFFICE-BUILDINGS. 22$ Thirteen 15-in. 42-!!). beams will provide for the total load within a small amount, which, considering the nature of the load, can be neglected. See the illustration Fig. 104. Where two columns carrying unequal loads rest upon the same gril- lage, care should be taken to have the centre of gravity of the grillage coincide with the point of application of the result- lint of the loads on the columns, in order to secure uniform pressure on the footing. 226 THE PLANNING AND CONSTRUCTION OF CHAPTER VIII. THE MACHINERY-HALL. THE continued success in a commercial sense of a high office-building is undoubtedly due to its perfected mechani- cal services, and in planning the building the architect will be required to seek the service of engineers who have made these branches of mechanics their special study. The dif- ference between the cost of operating a badly designed plant and one properly designed will in many cases be the measure of success or failure. In the matter of space strict economy should not be prac- tised in placing machinery, as the proper disposition of its parts in a mechanical sense will no doubt make it do its work- more economically and probably give it a much longer life. In designing the machinery-hall it is important that the boiler, chimney, engines, pumps, elevators, and dynamos should not be restricted to hot or damp places, as their life is just so long under good conditions, and is rapidly short- ened if every facility for maintenance is not afforded. So. too, with the question of labor. If firemen are to operate in dark, hot places, or with a severe strain of attention, they cannot do advantageous work. Quoting from an authority on the subject. " It will be found sometimes that an appara- tus which is more costly in fuel may be the cheaper one to employ, if its action is so reliable as to reduce labor and at- tention to a greater extent. Itisquite possible that in arrang- ing a plant the engine and tire-room staff may in one case be double that required in another. Xo plant should be settled HIGH OfFlCE-RL'Il.DIXGS. 22"J upon until the owner is satisfied as to what he will have to pay for labor, operation, maintenance, and depreciation. It is the little details of space, arrangement, and proportion that decide these economically. These little details are nu- merous and connected with every operating part. The posi- tion of boilers, of fuel, of valves, and the access for cleaning, lubrication, light, ventilation, all bear a part in deciding a day's work. With these preliminary considerations, and presuming we have with them a willingness to provide the best space and position which the building will economically afford for the proposed equipment, we start to consider its details. ' The first question that arises is, whether a power plant shall be installed to operate the equipment. There is likely to be electricity, water, and gas in the street. and these combined may afford the necessary facilities. There are cases where they do so even at an economy, chiefly an economy of labor. If the water service is at sufficient pressure, it will deliver to the roof. If the gas is cheap and of regular quality, it can be used in a gas-engine to provide light or to pump water. If the electric supply is cheap and dependable, it may be used for both purposes, or even for a little heating work. (Jas- engines are not capable of the closest regulation of speed, but are verv serviceable even in inexperienced hands. The petroleum-engine is equally so. lUit when large services are required, disadvantages arc encountered. It is the same with electric street supply. It may in some cases pay for its extra cost in the saving of labor and cost of plant. Where the work is large, it will not do so. The chief weakness of the above is in the fact that they do not cover the necessitv of heating. In Xew \ ork C'ity there is a steam supplv to be obtained, but its cost is prohibitory. Net there are cases where it has been found an economv to mill out boilers and 22 THE PLANNING AND CONSTRUCTION OF make use of the street supply. This would not be the case with a well-designed plant. Sometimes a near neighbor may have a reliable steam-service to spare, and in such case most advantageous arrangements may be made. Any large power station has exhaust steam, which it could afford to give away if the condensed water were returned to it. A couple of pipes laid under the street is all the outside disturbance necessary. The same remarks hold good, in degree, of electric supply, with which many plants could supply their neighbors at a very low rate. " Granted the decision to be in favor of an isolated plant, the following questions arise for decision: The chimney is in some ways the most difficult problem, because its results are so uncertain. Study and judgment are quite as neces- sary as scientific rule in deciding its proportions and loca- tion. Xo two of the established rules give equal conditions. Surroundings, wind, temperature, all affect its pulling powers, and when these are decided the access and travel of air to the furnace will still further affect the result. The quality of coal, its delivery and storage, need experience and solicitude. There are coals suited to certain conditions, and a more expensive coal may prove the cheaper investment bv its economy in handling. The claims of boiler-makers are not to be relied upon in this connection. " Boilers are the life of an installation, and at the same time quite its most vulnerable point. Their name is legion and their faults as numerous. A knowledge of boiler con- struction and design is absolutely necessary to enable a safe and fair comparison to be made of their respective features, merits, and demerits. It is not too much to say that all are faulty, and that as much depends on the way they are made as upon the form in which they are made. Xo boiler should be purchased until the facilities, methods, tools, and materi- HIGH OFFICE-BUILDINGS. 229 230 THE PLANNING AND CONSTRUCTION OF als used in the boiler-shop are known. The inspection of in- surance companies is very small matter for reliance, and police inspection is a farce under present systems. To a large extent the services of office-buildings hinge on the pro- portions of elevator duty. It requires the closest considera- tion as to its extent and schedule, while the proportions of cages and of doors affect the result almost equally with speed. Many buildings are oversupplied, more are under- supplied. The number is frequently fixed by reference to other buildings, which if analyzed would be found largely in error. The cost of the service has been the subject of lively agitation in engineering circles, and the respective solutions offered by hydraulic and by electric power have been acri- moniously discussed. The matter must be decided by a dispassionate consideration of the bearings, not only in cost of fuel but in labor, in first cost and in maintenance." THE MACHINERY-HALL OF THE CENTRAL RANK BTILD- ixr, DESCRIBED. The illustration Fig. 105 shows somewhat in detail the general arrangement of the machinery depart- ment of the Central Bank Building. The boiler-room is at the east end of the building and is about 5 ft. deeper than the engine-room, from which it is separated by a partition of brick and glass. The boilers are arranged as shown, and con- nected to the vertical circular smoke-flue. The steam-sup- ply pipes are overhead, as shown by the full line, and the ex- haust-pipes are in trendies underground, as shown bv the broken lines. The space in the boiler-room not taken up by the boilers and for stoking is devoted to the tire, house, feed, and drip pumps, etc. That part of the engine-room not re- quired of machinery contains the engineers' quarters, house- supplv and electric-supply fixtures, etc. BOILERS. The boilers of the Central Bank Building are of the water-tube type. Fig. ion and section Fig. 107, and ///9 gallons, 263 cubic feet. No. 2 3350 " 444 " Xo. 3 3939 " 525 " Crate Surface. Xo. i 7 feet long, 138 square feet. Xo. 2 7 " " 138 " " Xo. 3 7 " " 138 " HIGH OFFICE'S U1LD INGS, 234 THE PLANNING AND CONSTRUCTION OF The working pressure is no pounds per square inch. The space for the three boilers is in the sub-basement as shown on the plan, affording 16.9 feet for the double setting and 11.6 feet for the single setting. The headroom above stoking-level is \ 5 feet, with a drop of one foot for a false ceiling, which is made of steel tees rilled in between with magnesia blocks. The steam and water drains are of large proportions, and constructed of " open-hearth " steel plates, having a tensile strength of 60,000 pounds per square inch. The drums are double-riveted in longitudinal seams, dished and flanged by a hydraulic press. Edges of plates are planed and caulked. Horizontal seams are double-riveted and girth-seams are single-riveted, by steam-power. The manholes and lids are of the same steel, provided in each drum with reinforcing- plates riveted around all manholes. Steam-nozzles are provided in each boiler as follows : \o. i, 5 in. dia. ; Xo. 2, 6 in. dia.; Xo. 3, 8 in. dia. The boiler-fronts are of cast iron neatly panelled, and the tire-bars are of Ward's dumping pattern for burning buckwheat coal Mountings of Boiler. Xo. i . two nickel safety-valves 3 in. dia. Xo. 2, 4 ' X'o- 3. 5 Xo. i, one feed-stop and one feed check-valve i } in. No. 2, " " " ii " Xo. 3. ' " 2 " Xo. i. blow-off cocks, Fairbanks, 2 in. Xo. 2. " " " " 2 " Xo. 3. " 2$" HIGH OFFICE-BUILDINGS. 235 For each boiler there are provided one Reliance water- column with improved connection to levels, gauges, cocks, etc. ; a 1 2-inch Marsh illuminated-dial steam-gauge ; one set of fire-tools; one complete set of wrenches, mounted on board and hung in stoke-hole; and one steam-jet hose. These boilers have many good points of recommenda- tion; namely, straight, smooth passages through the head- ers of ample area, insuring rapid and uninterrupted circula- tion of the water; the baffling of the gases (without throt- tling or impeding the circulation of the water) in such a way that they are compelled to pass over every portion of the heating surface ; sufficient liberating surface in the steam- drums to insure dry steam, with large body of water in re- serve to draw from; simplicity in construction; accessibil- ity for cleaning and inspection. All stay-bolted surfaces are omitted. The possibility of rupture is eliminated from the fact that the headers in their design provide for the unequal expansion and contraction of the long tubes. These headers have inside plates, and the higher the pressure the more secure are the joints. KXGIXKS. There are three direct-connected single- cylinder automatic cut-off engines. (See illustration Fig. 108.) Engine "A", the largest 15 > 14 in., direct-connected to the ioo-K.\\ . generator. (icncral Dimensions, etc. Horse-power 180, based on 250 revolutions per minute. Diameter of cylinder 15 in. Length of stroke 14 in. Diameter of governor-wheel 70 in.; weight 4480 Ibs. \\ idth of face of governor-wheel 15 in. 236 THE PLANNING AND CONSTRUCTION OF Length of engine over all 10 ft. 7 in.; weight complete 15,500 Ibs. Width of engine over all 9 ft. Diameter of steam-pipe 5 in. Diameter of exhaust-pipe 7 in. Diameter of crank-pin 7^ in. Engine "B" iixi2 in., direct-connected to the 75- K.\Y. generator. General Dimensions. Horse-power 90, based on 275 revolutions per minute. Diameter of cylinder 1 1 in. Length of stroke 12 in. Diameter of governor-wheel 60 in.; weight 2225 Ibs. \Yidth of face of governor-wheel 12 in. Length of engine over all 9 ft. 3 in.; weight io,oco Ibs. Width of engine over all 8 ft. Diameter of steam-pipes 4 in. Diameter of exhaust-pipes 5 in. Diameter of crank-pin 6 in. Engine " C ' 9 x 10 in., direct-connected to the 25-K.\Y. generator. General Dimensions, etc. Horse-power 50, based on 300 revolutions per minute. Diameter of cylinder 9 in. Length of stroke 10 in. Diameter of governor-wheel 50 in.; weight 14/2 Ibs. Width of face of governor-wheel 9 in. Length of engine over all 7 ft. 8 in.; weight 6000 Ibs. Width of engine over all 6 ft. 4 in. Diameter of steam-pipe 3i in. Diameter of exhaust-pipe 4^ in. Diameter of crank-pin 5 in. HltJff OFFICE-BUILDINGS. 257 Fittings. Each engine is furnished with the following fittings, which include everything necessary for a complete outfit: One throttle-valve. One exhaust-valve. Full set of sight-feed oil-cups nickelled. ( )ne Detroit sight-feed lubricator, double glass, nickelled. Full set of finished steel wrenches. ( )ne engineer's wrench-board. Full set of handles for removing steam-chest cover, pis- ton, and other parts. Full set of valves, steam-cocks, bibb-cock, etc., far all drips. Full set of foundation-bolts with anchor-plates and fin- ished cup-nuts for engine and dynamo foundation. DYNAMOS. The following is a description of the three dynamos in connection with the above engines: One having capacity of 100 K.\Y., marked " A.'' One having capacity of 50 KAY., " B." One having capacity of 25 KAY.. " C. v Details of these dynamos are as follows: "A." " B." "C." Type of dynamo .M.I'. i>- 100-250. M.P. 6-50-280. M.P. 6-25-305. Number of poles 6 6 6 Kilowatts 100 50 25 Voltage I K) to 125 i 10 to 125 I 10 to 125 Amperes 800 400 200 Required speed 250 rev. 275 rev. 300 rev. Approximate weights.. 7600 Ibs. 6200 Ihs. 2700 Ibs. The field-frames and pole-pieces are of soft cast steel of the highest magnetic permeability; the field-coils are wound on metal spools and insulated therefrom by standard mica and fibre insulation. The armatures are of the ventilated type, built ii]) of soft-steel plates. The winding is of the barrel pattern with flexible connections to commutator. The 2 3 8 THE PLANNING AXD CONSTRUCTION Of- commutator is of the carbon-brush type, with a sufficient number of carbon brushes so that the current density does not exceed 40 amperes per square inch of surface. FIG. 108. DIRECT-CONNECTED ENGINK AND GENERATOR, CENTRAL HANK BUILDING. ELECTRIC-LIGHT INSTALLATION ix THE CENTRAL BANK BriLDiNG. The lighting installation in the Central Bank Building consists of a complete conduit and wiring system of fifteen floors, basement and subbasement. to 1/96 outlets, arranged for about 2031 incandescent lamps of if> candle- power. 72 of 32 candle-power, and for 20 arc-lamps. The system employed is the vertical-circuit arrangement. 3-wirc to 2-wire, for Edison Co. supply and house-supply. The dis- tribution-boxes are situated in the subbasement, and the junction-boxes are upon the sixth and seventh floors. The arc-light circuits are run out from the nearest vertical feeder, and each lam]) is provided with a switch. The vertical arrangement consists of nine 3-wire main feeders from the switchboard to the nine distribution-boxes. thence 3-wire subfeeders carried to location of each vertical circuit. The vertical circuits are 50 in number. Thence the neutral and one outside wire are carried to a HIGH OFFICE-BUILDINGS. 239 junction-box on the middle floor. The third wire is carried up as one leg of the vertical circuit. The vertical circuit in 2-wire extends from subbasement SANK fg] D/ST. . Fn;. iO(|.--\'KKTic,vi. AKRANC.KMKNT OF ELECTRIC WIKINC, SYSTKM. to top-tloor outlet. The arrangement is as shown on dia- gram. Fig. 109. requiring two conduits from distribution-box to junction-box of each circuit, with two wires in each. 24O THE PLANNING AND CONSTRUCTION' OF Thence one conduit to top-floor outlet, with two wires in same. The Bank floor has a separate feeder. The conduits throughout the building- are the interior Conduit Co.'s. The wire employed is that known as the Grimshaw White Core, All the tubes extend up the columns, and where two or four lights are placed on opposite sides of the column the tubes were bent at the corners to a radius of 6 inches, so that it was possible to draw the wires without injury. The distribution-boxes, located as heretofore mentioned, are built on the adjustable system, that is, a box within a box. having a common slate back with space to allow of connec- tion being arranged all at one side. The boxes are built of oak to match the interior trim of the building, lined with slate ] in. thick secured with brass screws. The panelled door is similarly lined, has brass hinges, and is secured with lock and key. The outlet-boxes are of cast iron of a specially designed pattern, about ^\ in. square, and set in flush with the plas- tering. All the offices have a floor outlet-box set in a convenient manner for an office desk, 6 in. above the floor. The elevator-cable outlets, six in number for twelve- lamps, are situated midway up the elevator-shafts. The five passenger-elevator outlets are run as one separate circuit from the nearest distribution-box. SwrrciiJiOAkn OF TIIK CKXTKAL I>AXK I'TILDI x<;. The switchboard of the building is arranged as shown by the illus- tration. Fig. i 10. The board is of white Italian 6 ft. 6 in. wide, 8 ft. high, and i! in. thick, and located as shown on the plan. It is HIC.H OFFICE-BUILD L\GS. 241 >ecured to an angle-iron frame extending around it, and is supported by iron legs and thoroughly braced. aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aan aaa aaa 200 A M P qpoumnia bw aan DYNAMO ^*i nan DVhAMO HIS ana 8O04MP DOU5LC 5LADE aan aaa 4OOAMP mGLC DL4DC Flli. 1IO. DlAURA.M 01 S\\ 1 I (HliOA KI) IN T UK CK.NTKAI. 1 J )ANK Hi ILIHNC,. The board is fitted up with the following instruments and fixtures: j \Veston station illuminated-pattern voltmeter to 250 v(^lts, complete with 5-p/ the passenger-elevators are hydraulic, as is also the ash-hoist; but the freight-elevator is operated by steam. The five pas- senger-elevators are arranged in two shafts, as shown by the regular floor-plan in another chapter, three in one and two in the other. A plan of the two elevators is shown in Fig- o 112. O I I ! 2-9" i DOOK 2-S- 4 IS' -4 _' ft. 6 in. xu ft. x 9 ft. deep. A \Yestinghouse duplex air-compressor having cylinders ~\ y ^ / () in. is mounted upon a column adjoining and con- nect ed complete to the storage-tanks. The elevator-cylinders, as will be seen by the illustration. Fig. 113. are vertical, 15 inches in diameter; numbers I and 2 being 45 ft. 9 in. long and numbers 3, 4, and 5. 43 ft. (i in. long. Xumbers i and 2 are longer on account of extending cars to basement. These cylinders are of cast iron, of proper proportion for a working pressure of 150 Ibs. per square inch. The cage is of wrought iron with forged rods securely braced, and supports a car of cast iron and steel. See illus- tration. Fig. 136, ("hap. X. O FFl CE- B UIL I) ING S. 249 CELLAR SEC Fn;. 114. H VDK.M i.n' ASH-HOIST, CKNTR.M, BANK SAftTT I Nuit Oi Fi<;. 115. Hoisnx<;-M'T KOK F,i FR MACHINK. 250 THE PLANNING AND CONSTRUCTION OF The cables carrying these cars are four in number, of steel, | inch in diameter, having six strands, 19 wires to the strand, and capable of a safe load of 14,000 Ibs. The cars are also provided with counterweighing chains, slung free in the shaft. The sheaves are of cast iron, 40, 42, 47, and 51 inches in diameter. The freight-elevator, of the steam-drum type, has the same height lift as the passenger-elevators, but is capable of raising a maximum load of 6000 Ibs. Speed at a load of 1000 Ibs., 300 feet per minute. It has a compound gear which can be thrown in for lifting up to 6000 Ibs. weight. The cables are two in number, of steel, inch in diameter, each having six strands, 19 wires to the strand. This car is provided with a hand-rope control, while the passenger-elevators have a lever device. The ash-hoist is hydraulic, as shown by the detail drawing, Fig. 1 14. The cylinder is of cast iron, sunk into a well composed of a wrought-iron tube driven into the ground. The plunger is of cold-rolled steel. The workman- ship and materials throughout the work are of the best, and at this writing, eight months after it was first operated, the plant is practically perfect. ELECTRIC ELEVATORS OF LORD'S COURT BUILUIXG. The five elevator-shafts as shown upon the plan (Fig. 37, Chapter II.) of Lord's Court Building are provided with cars operated by the horizontal multiple-sheave type, with a travelling cross-head and frictionless nut (see Fig. 115) driven by a i-i-inch pitch-screw, revolved by a motor directly connected. The entire operative machinery, both electric and mechanical, is self-contained, and is placed in the base- ment in two double-decked sets and one single set. (See illustrations. Figs, iifiand 117.) The general dimensions are as follows: Length of machine over all, 28 feet; height, 3} by 7 feet; width, 3.^ feet; HIGH OFFICE-BUILDINGS. 251 sheave-multiplication, 8 and 2; diameter of sheaves, 36 inches on machines; number of hoisting-ropes, 4. The motor is of the four-pole type, and the winding is strongly compounded. The carbon brushes are double, have independent movement and ample capacity to call the full current under all conditions. The machine is self-oiling, and the main bearings are accurately lined. The main brake, con- sists of an accurately turned flanged pulley carried on the inboard end of the screw, which is gripped by a wood-lined steel band anchored on one side and continually pulled down on the other by a powerful spring under adjustable compres- sion. This brake is released on hoisting by the hoisting-cur- rent, and in going down by a special circuit. On failure of current for any reason, or when running down at an excess of speed, the brake instantly becomes operative, and whenever the machine stops the brake is automatically locked. The screw machine has a capacity to lift a live load of 2500 pounds exclusive of the excess of car and cables, at 400 feet per min- ute and a hoisting speed of 500 feet per minute with the average load, all with a potential of 120 volts at the motor terminals. The four ^-inch lifting-cables have a tensile strength of 17,000 pounds, with an allowed working load of 3200 pounds each. The regulator is operated by a small electric motor, controlled by an " up-and-down " and automatic-stop lever or button, placed inside the car, giving the operator full con- trol of its speed and direction. The cars and motors are equipped with safety-brakes, automatic stops, slack-cable devices, and all appliances necessary for the safe operation of the same. These five machines are driven by three direct-connected engines and dynamos of 100 KAY. capacity and one 50- KAY. 252 THE PLANNING AND CONSTRUCTION OF HIGH OFFICE'S UILD ING 6'. 253 254 THE PLANNING AND CONSTRUCTION OF machine, which also supply the electric lighting for the en- tire building. AIR-CUSHIONS FOR ELEVATORS. There have been sev- eral serious accidents in connection with the elevators in high office-buildings this past year, some on account of incom- petent operatives and others by reason of imperfect machin- ery. As the elevator is without doubt a labor- and time- saving device and positively necessary for the success of the building in which it is placed, no consideration should stand in the way of reducing to a minimum the element of danger. The manufacturers of these machines declare that the average " elevator-man " or " elevator-boy " is incapable of properly operating them. Yet these complicated machines are often placed in charge of men or boys whose qualifica- tions are limited to a superficial acquaintance with the work- ing power and safety appliances. With respect to these latter, each company claims that its own are the only reliable ones, and yet it is a fact that nearly all have grave faults. The device which with various modifications is common to most elevators is a governor beneath the car and which, operated by the latter, acts upon steel shoes that grip the guides on the side of the shaft. The governor is set to act when the speed of the car passes one hundred feet a minute ;;bove the safety limit. But a serious smash-up could occur before reaching this rate of speed should the car run away. Another possible cause is neglect on the side of the engineer to keep the parts properly cleaned and oiled. A scheme which is in use in a few buildings and has given good satisfaction is an air-cushion in the bottom of the shaft. The lower part of the shaft for a distance of several feet is made air-tight. When the falling car drops into this " tube " the air below is compressed and acts as a cushion, and the stop is made gradual by the escape of the air around the sides HIGH OFFICE-BUILDINGS. 255 of the car. We believe this is the only safeguard against accidents from falling elevator-cars, and a law should be passed making it compulsory for owners to have such air- cushions in the elevator-shafts of their buildings. STEAM-HEATING. THE HEATING OF TALL I>riLnixr,s \\\ EXHAUST STEAM. Among the many problems presented by the increasing heights of office-buildings, none has thus far been of a more perplexing character than the question of efficient circula- tion of steam for heating purposes. In the older buildings of moderate height the distance of the furthest radiator from the source of supply was not great enough to require much pressure to effect the required cir- culation and to exude the air-gases, and therefore it was that the general use of exhaust steam for the work came about. The increase of height, upon the introduction of tall buildings, was not gradual, but went at a bound from five to fifteen and thence to twenty floors and upwards, or, ex- pressing it in relative heights, from do feet to JOG or 250 or more. Those who are best acquainted with the theory and prac- tice of steam-circulation foresaw that the result must inevi- tably be the introduction of some means -of effectively and definitely aiding the natural power of circulation and of re- moving the gases without increasing the pressure required: and such a development has taken place in the form of the apparatus described below. The first point to be arrived at is to avoid the imposition upon the exhaust or waste steam of the engines or pumps of any excess of pressure over that of old practice: but an ideal plant would naturally accomplish more than this, and would 2$6 THE PLANNING AND CONSTRUCTION OF reduce that pressure, commonly known as " back-pressure," to the level of atmospheric pressure, thus leaving the engine in the same condition of freedom as if its exhaust were being freely delivered to the open air. In common practice the required back-pressure is ef- fected by a loaded retarding or " back-pressure valve " placed upon the outlet to the atmosphere, thereby confining the steam to the system of pipes and radiators within the building, but capable of being loaded so as to impose upon the engines or pumps a back-pressure of such an extent as will suffice to impart the necessary velocity to the steam, in order to cause it to flow through mains and branches, and into radiators or coils, in sufficient quantity to force out gases and provide for condensation. The only means of reducing the back-pressure necessary for a given installation of such a description lay, under the old practice, in the increase of the proportions of pipes throughout, with the result that, as the length of mains and branches was increased by the extension of the height of buildings, the sizes of pipes were necessarily disproportion- ately increased.- greatly adding to the cost of the plant. Various methods of providing for the exudation of air- gases was devised, the most promising being that known as the " wet return." in which the return-risers were so run as to maintain a water-column at the lowest point an arrange- ment often involving trenches or the laying of pipes, and reducing the economy of the system by the lowering of tem- perature due to the water always lying in these pipes. The back-pressure necessary under the best proportion- ing and arranging of such systems is, in tall buildings and in full operation, often as much as 15 pounds per square inch, under which the economy of engines and pumps is greatly reduced and their demands for steam are proportionately HIGH OFFICE-BL'ILDIXCS. 2$? increased. The result is forcibly illustrated in such of the tall buildings as retain installations of this character. In severe weather, far from the entire exhaust of pumps and engines being swallowed up by the heating system, it will often be seen emerging from the escape-pipes in in- creasing quantity as the seventy of weather increases. This effect is but natural: the greater the demand of the radiators, the greater, under these systems, the requirements of back-pressure, and the greater, consequently, the demand of the pump for steam; the result being that the system be- comes overcharged, and surplus is discharged to the air through the retarding-valve. This increased demand for steam due to back-pressure often imposes so great a duty on the engines that it is more economical to use live steam at required pressure for heating, and waste the exhaust to the atmosphere. Much that is misleading has been written in endeavoring to minimize the effects of back-pressure in engines and pump-cylinders; the actual operation can, however, be read- ily appreciated by any one familiar with the action of steam within cylinders; and at whatever point the pressure and back-pressure stands, the disadvantage of the latter is rela- tive not merely to the former, but to the mean or average pressure on the piston. Before entering upon the details of this subject, it may be well to describe briefly, for the sake of those who arc un- acquainted with such matters, the theory of steam-heating. In the raising of water from a lower temperature to that of the boiling-point a certain amount of heat is required, but much more heat is necessary to evaporate the boiling water into steam. In point of fact, there is required to heat freezing water to a boiling temperature only one fifth of the heat required to turn the same boiling water into steam. THE PLANNING AND CONSTRUCTION OF The steam may and will be of only the same actual tempera- ture as the boiling water, that is to say, 212 degrees Fahren- heit, but the heat is demanded by the act of evaporation or liberation of the vapor. It is now general scientific practice to express the values of heat in heat-units, one such unit being, in American and English practice, that amount of heat which is absorbed by a pound of water raised in temperature one degree Fahren- heitthe convenience resulting from this simple method being readily apparent. Expressed in this manner, the num- ber of heat-units absorbed by a pound of boiling water raised from freezing-point is 180, all of which can be traced by ther- mometer and is therefore known as sensible heat, while the number of heat-units absorbed by the same pound of water liberated into steam is nearly 965, which is described as " latent " heat since it does not affect the temperature and is not measurable by thermometer. To raise the steam to a working pressure for engines or pumps requires a still further addition of heat, which is also measurable, and is parted with by the steam during its work in the engine or pump, the exhaust or waste emerging properly at atmos- pheric pressure and containing then the latent heat as well as the sensible heat of 180 degrees per pound previously re- ferred to. It is the latent heat. then, that is parted with by the steam in the operation of warming a radiator or pipe, with the result that, as soon as it is parted with, the vapor again becomes water, at or near boiling temperature, or. in other words, is condensed. In such a form it is still of value as compared with cold water for feeding the boiler. An ideal heating plant would therefore be one in which the steam of any given working pressure is utilized first in operating engines and pumps, emerging freely from the ex- ///(/'// OFFICE-BUILDINGS. 259 haust of same, and being then fully utilized in radiators till its latent heat has been parted with in the work of warming rooms, leaving it in the form of condensed hot water to be returned to the boiler for re-evaporation. The nearer this ideal condition can be attained in practice the more economi- cal the heating system will become. There is another feature which comes into active opera- tion during this process, and which is the cause of most of the difficulty presented in practice. All water contains air with more or less impurities which, mingling with the steam in the boiler, retard the action of evaporation, absorb some of the heat, become dissociated into various noxious gases which are carried away mechanically by the rush of steam, lodge in the pipes at ends, turns, and bends, and prevent the sfeam from reaching those points. The removal of this air or gas is thus of the first neces- sity, and the devices known as air-valves are designed for this purpose. They afford a minute opening for the exit of the air. which closes up on the approach of steam. The air must be pressed upon by the steam to find an exit by this means, and thus the indirect effect of the pressure of air- gases is to demand a pressure of steam for heating work, which would otherwise be unnecessary. The air-gases emitted into rooms have an unpleasant odor, and a special line of pipes for their eventual conduc- tion to some vent or sewer is thus rendered necessary. L'nder the improved apparatus presently to be described it will be seen how this problem is dealt with. The removal of the air-gases leaves the condensed water in the form known as "distilled," when it is free from gases, but is so far reduced in quantity that an addition of extra water is al- ways required to make up its bulk to the normal rate of con- sumption. 260 THE PLANNING AND CONSTRUCTION OF This additional water, known in condensing plants and in marine practice as the " make-up," is an element liable to disturb the whole economy of the cycle of operation by the air entrained in the water, and also by difference in tempera- ture unless its temperature be raised previous to its entry to the system by means of some waste heat or, preferably, by mingling with it some small portion of steam the full value of which may thus be conserved. To reduce back-pressure to a minimum, to reduce also the sizes of pipes required for a given circulation, to remove automatically and effectively the air-gases, as well as to re- turn promptly the water of condensation with the least pos- sible delay and loss of heat, and to do all without noise, form the general problem of the heating of tall buildings. This problem is effectively solved by the \Yebster system, now to- be described. The system provides a complete and automatic flexi- bility of circulation, so that the maximum supply may be applied at one portion of the pipes, and a lesser amount or none, as may be desired, at other portions. Thus the exposed side of the buildings draws naturally the largest supply, and offers no difficulty from surcharged return-pipes in so doing; while a distribution of less steam to another portion may be taking place, and a more moder- ate heating effect produced there. The \Yebster system comprises primarily an automatic outlet-valve to each part requiring drainage, a connecting system of return-pipes to a suction apparatus, such as a pump or an ejector, the positive abstraction by this means of all air-gases from the heating system, and the return of the condensed water into a heater wherein the water and gases freely dissociate in a chamber sealed from the atmosphere, and where the temperature of the condensed water plus that HHiH OFFICE-BUILDINGS. 26 1 of any .additional fresh supply found to he necessary is raised by direct contact with a proportional amount of exhaust or waste steam, and finally the return of the whole automati- cally to the boiler. The operation of this apparatus can be brought to any degree of automatic regulation; its control is entirely in the engineer's or fireman's discretion, while leaving the control of each individual radiator or coil absolutely in the hands of the tenant, or occupant, by means of one inlet hand-valve only to each such radiator or coil, the outlet-valve being automatic. A remarkable result due to this arrangement is the ability to reduce the total temperature of any separate coil or radi- ator by reducing the amount of steam admitted to it without waterlogging or hammering, a result unknown with any other combination of steam-heating apparatus. This is done at will by closing down on the inlet-supply to the desired degree. The result is the admission of a smaller amount of steam to the coil than it is calculated to condense normally, or, in other words, less steam is delivered than suffices to fill the radiator at atmospheric pressure, and consequently steam enters as a tenuous vapor, finding no obstruction from air-gases, and affording a moderated tem- perature capable of graduation down to that just above the atmosphere surrounding the radiator, and precisely in pro- portion to the heat-units liberated from the quantity of steam admitted. In this is to be found that much-sought desid- eratum, of steam-heating engineers, the moderation of heat- ing to suit mild weather. The diagrams presented herewith illustrate the application of the \Yebster apparatus in the Central Bank Building; its flexibility to other conditions will be at once apparent. The preferred arrangement consists primarily of a ther- 262 THE PLANNING AND CONSTRUCTION OF mostatic valve, which is shown in enlarged section in Figs. 1 1 8, 119, and contains a stalk or stem of hard-rubber com- pound which expands rapidly under increasing temperatures. FIGURE 1 FIGURE 3 FIGURE 2 FK; 1 1 >. 'In EKMOSTATH: VALVES OK 'inn WEBSTER SYSTEM. The seat, which is the outlet, is arranged for read}' adjust- ment by a screw-driver. It is capable of being set so that it will open at any required degree of temperature. In opera- Fir; TIQ. ANOTHER VALVE OK THE WEBSTER SYSTEM. tion it is practically closed while steam is in the coil and in contact with the stalk, but as soon as condensation collects around it the stem shortens and opens the aperture to the return-pipes, in which a suction or partial vacuum is main- tained by an air-pump connected to main return, from which HIGH OF I- 1CE-B UILDING S. 263 the condensed water and the air-gases are drawn out, the stalk again lengthening and closing the aperture as soon as steam reaches it. The thermostatic value is placed at the point of drainage of the coil or radiator, as shown in Fig. 120. One of the standard size adopted is capable of draining upwards of 200 square feet of surface in active condensation. In he same or another form it is applied to the foot of riser-pipes as shown in Fig. 1 18, to the ends of horizontal lines, to changes of size of pipes, and in fact to any desired point where con- densation is liable to collect. Heavy condensation of any part can be dealt with by multiplying the number of thermostatic valves at that point The valve is so placed that dirt and scale in the pipes do I'll,. 120. TllK Tlll'-.KMOST.vrir Vu.VKS IN CO.NNKCTION WITH R A Ul A 1 < >K>. not fall into it direct and choke its inlet, as provided for by the drop-leg shown in Fig. i iS. Its form is, however, such as will allow for a certain amount of sediment to deposit around the stalk, which is protected by a perforated screen of simple character. In Fig. 120 is shown a return-line by which the condensed water is lifted by the action of the suc- tion from the bottom of the right-hand coil. Proceeding now to the arrangements illustrated in the 264 THE PLANNING AND CONSTRUCTION OF diagram, Fig. 121, which illustrates the basement, engine- room, or boiler-room, a return-pump is shown which is a direct-acting " wet-vacuum " pump, and is regulated to main- tain a constant amount of suction, by means of a pump-gov- ernor of special design, operated by the action of the suction on a diaphragm. This governor is shown connected in the line of steam-supply to the vacuum-pump. The return-pipes being united and brought to the pump, HIGH OFFICE-BUILDINGS 265 it is set to receive the condensation and to exert an extra suction of from one to fifteen inches of mercury, according to requirements. A pump for a radiating surface of 20,000 square feet has a steam end six inches in diameter and will make about sixty feet piston-speed per minute. Its exhaust is taken into the heating-main, and it is thus operated merely as a reducing-valve, or it may be taken direct to the feed-water heater and there condensed. The delivery of the hot returns can be effected in more than one manner. The best system has been found to be to deliver the whole into an overhead " hot-well " or return- receiver as shown, from which free egress for the air and vapors can be afforded to the atmosphere and time allowed for the separation to effect itself thoroughly. From the receiver the hot water, freed of air-gases by the vertical relief- pipe, gravitates to the feed-water heater. The make-up water is dealt with by its introduction into the system at a point where it may be made of most effective use. It is connected to a small jet in the return-pipe at its point of connection to the vacuum-pump. Here it condenses the air-gases as they are drawn towards the pump, imparting its velocity to them and aiding the action of the pump. It may, if not required on this service, be diverted to the over- head receiver, there mingling with the returns, or it may be passed direct into the feed-heater, and in ail cases it is con- trollable at the discretion of the fireman, who has thus under his hand the extent of total feed-water returning to the boiler. The \Yebster feed-heater, an illustration of which, show- ing the interior apparatus, is annexed (Fig. uj). is an integral portion of the cycle of operation in the heating sys- tem, and is practically one unit of the radiating surface, pro- portioned to receive the condensation of all other surfaces, to mingle with them some steam drawn for the purpose from 266 THE PLANNING AND CONSTRUCTION OF the general supply, and finally to be continuously relieved by the feed-pumps. It enacts precisely the part of the digestive organs of the Fu;. 122. INTERIOR VIKW OF THE WKHSTER FEED-HEATER. human system, receiving the alimentary materials, reducing them to the necessary conditions of reception by the organs, discharging the surplus as well as the deleterious and waste HIGH OFFICE-BUILDINGS. 267 products, and delivering the required total in the best possi- ble condition for reuse. Referring- both to the illustration and to Fig. i?i. it will be seen that it is only to be described as of the " open " type of feed-heater, in so far as that a portion of the waste or exhaust steam is brought into actual contact with, and is condensed by, the feed-water proper. It consists of a closed or sealed chamber, rectangular in form, provided with an upper inlet for the feed-supply, which may be hot returns or cold water or both, and an inlet for steam provided with an independent oil-separator or grease- extractor, operating upon the steam previous to its entry to the interior. Upon entering, the steam encounters a set of oppositely inclined and perforated trays of copper sheet, over which the feed-water from above is spread and percolates in a very finely divided condition, inviting most effectively the absorption of heat from the ascending steam-particles. Am vapor or gases from the entering steam that escape the con- densation of this process encounter above the upper tray a coil of parallel brass tubes through which the entering feed- water passes on its way to the trays. The effect is thoroughly to condense such gases or vapors and leave them in condition readv for removal bv the air-pipe provided, which may be treated, as shown, by connection through a thermostatic valve into the \Vebster system, or may vent to the atmosphere. The body of reheated water, accumulating in the lower portion of the heater, affords a de- sirable opportunity for the settlement of solids, to be drawn off by the inclined bottom and drain-pipe below, and is also provided with an outlet above the water-surface to take ott floating scum or impurities of light specific gravity. The outlet to the feed-pump is provided under a plate hood extending down into the bodv of water and excluding 268 THE PLANNING AND CONSTRUCTION OF the surface impurities. Upon the normal water-surface is arranged a copper float-box, operating, through the only exterior gland, a lever, which may be arranged as shown to control the steam-supply to the feed-pump. The feed-water heater thus raises the temperature of returns combined with the make-up or cold feed, together with the condensation of the radiators, to the full temperature due to contact with the steam admitted, bringing the net result of the cycle of opera- tion to the utmost possible utilization of the heat-units in the steam taken for the duty. Returning again to the question of circulation, it is an interesting result of the system that with any given amount of steam supplied to the pipes the distribution is equable and controllable. As the operation of circulation is not dependent on any pressure above the atmosphere, but is free to take place with- out obstruction of air or of condensation, and the speed of cir- culation is increased by initial How of steam at or about atmospheric pressure into radiators where, when requiring the maximum supply of steam, the pressure is considerably below the atmosphere, the pipe system even if of only mod- erately proportioned size is placed in its most effective con- dition, and the speed of the circulation is proportionately increased. Thus not only can much more steam be circulated through any given size of heat-supply pipes, but any degree of attenuated steam-vapor down to the point of partial vacuum reached by the suction or vacuum pump. The result is that pipes of smaller diameter both for heat supply and returns can be installed than with any form of gravity system. Experiment has shown that a thermostatic valve having connections of an area of . i square inch, or equivalent to a standard pipe of J inch diameter, will convey the condensa- tion and vapor from 300 square feet of radiating surface. So HIGH OFFICE-BUILDINGS. 269 small a pipe is, it is true, inadvisable in steam practice, merely on account of its liability to damage, and it has therefore been usual to connect each thermostatic valve by ^-inch pipe. This size may, in exposed or long horizontal lines, be still further increased to ^-inch diameter, but additions thereto as other return connections are brought into it need only to be made in the original proportion of .1 square inch to, say, each 100 square feet of surface. The accompanying comparative table of returns on both systems will show that quite a considerable economy is to be effected in this way over a two-pipe gravity system, and of course no air-gas pipes or air-valves are needed at all. In a large modern office-building in which the riser-lines are very extensive the economy is very considerable, as may be seen by the following table: CoMi'AKA TIVK PROPORTIONS OK RKTTRN Pirns IN WKHSTKK AND GRAVITY SYSTEMS. Vacuum Return. Vacuum Heat. Gravity Heat. Gravity Return. IOO sq. ft. IOO sq. ft. i" I ' ij' i" IOO IOO . A 1 1 I A j i IOO IOO A I-J 2 IOO IOO I i A 2 i A IOO ICO 3 2 2 A o IOO ico i 2 2.1 o IOO ioo i 2 3 2 A IOO IOO i 2A 3 2A IOO IOO One practical and very remarkable feature of this system must be noted. It is quite practicable to operate the returns from radiators situated below the floor of the engine-room or below the level of the return-pump, or to lift the drainage of any given portion to quite a considerable extent. The partial vacuum maintained and which extends 2/O THE PLANNING AND CONSTRUCTION OF through the return system will handle a much greater height of return than its theoretical value in inches of water. -The effect is doubtless due to the sweeping action of the removal of vapors with the condensation in the same pipe. No other means exist of solving this problem, and its practi- cability is a great convenience in many buildings. The uncertainties and irregularities of steam-heating are by this apparatus largely disposed of. and its adoption insures to the heating engineer a certainty of circulation, of drainage, of absence of noise, and of efficient return of heat to the boiler, which removes a great deal of responsibility and anx- iety as to results. Exposed particular portions of the system can be pro- vided with extra circulating facility, with or without reduc- tion at any other part. Xo necessity exists for that special cMid nice proportioning of supply and return lines which demands such certain and careful calculation and forethought in a gravity plant. Old and inefficient systems can be made efficient, and those in which extreme back-pressure has been necessary can be reduced to economical conditions. All this is due to the fact that the system operates by those natural laws which experience has shown to control the work of steam in circulation and condensation; laws which have long been recognized and successfully utilized in steam- engine practice, and which demand equal consideration by heating engineers. DESCRIPTION OF TIN-: HEATING AND POWER PLANT IN THE CENTRAL NATIONAL BANK. The general arrangement employed is a single-supply and single-return system of fif- teen lines of risers from mains carried around the sub-base- ment ceiling, the risers being laid along the lines of radiators with tee and cross connection beneath the finished floors. HIGH OFJ-'IL'E-HL'ILDIXGS. ?7 l r riie connecting' branches to each radiator are laid with spring-bend and union joints so as to avoid any movement by the radiator by expansion and contraction of the pipes. Chases are provided in the walls for the risers. The system is operated on the Webster combination vacuum plan as pre- viously described. The steam-heat main for house-supply is a 6-in. -diameter pipe, extending around the entire subbasement, to which the above fifteen lines are connected. This main is carried about i foot from the ceiling and supported by expansion hangers. The vertical lines are of first-quality wrought iron with screwed connections, each riser line being supplied with a screw-down valve at foot and a drop-leg of full-size pipe at bottom, with tee and Webster thermostatic valve and con- nection into return-line from same. The return-lines commence within i in. of each radiator and so continue, as shown in table of comparative proportions of return-pipes in both systems, as heretofore mentioned. The radiators are of the Bundy pattern and 425 in number. The radiators in the bank are placed in niches, and have an outlet from the outer air so that fresh air is supplied to the room through tines controlled by dampers; the vitiated air being carried to a vent-fine and out through the roof. The Stcciin-poii'cr Suf>f>/\. 'I he steam-power consists in supplying steam from the boilers to the engine and pumps through long-bend fittings from the outlet-valves of each boiler to the main steam-pipe, which is of wrought iron 10 inches in diameter, of best lap-welded quality, screwed into wronght-iron flanges. From the mo-II.P. boiler the pipe is 5 inches diameter, from the 140-!!. P. o inches, and from the 22O-11.P. S inches. The main stop-valve just beyond the !a-t boiler-connection is a in-inch Xelson double-seated high- pressure screw-down yoke-pattern valve. 272 THE PLANNING AND CONSTRUCTION OF The io-inch steam-supply pipe extends into engine-room, supported from the floor and not from the ceiling, and from it are led long-bend pipe-branches to the engines and pumps. These connections are carried from the top and provided with angle-valves. The pipes leading to the compound pumps are 4 inches in diameter, those leading to the two large engines 6 and 5 inches respectively, and that to the small engine 3 inches. The exhaust-pipes from these are for the two compound pumps 3 inches diameter, the two large engines 8 and 6 inches respectively, and the small engine 4 inches. The main exhaust is 10 inches in diameter and is placed in a ditch underneath the floor, and rises in boiler-room near pump-bench. In order to drain the pipe underground a Y, connecting to feed-heater, 6 inches in diameter with a 6-inch full-way gate, is provided. On line of main exhaust there is provided one exhaust- drum 2 ft. () in. by 5 ft., built of ]-inch steel plate, with dished heads, with an internal coil composed of brass pipe with return bends and baffle-plates removable through lid, and with two cleaning hand-holes and lids, a ii-inch drain-pipe, and screw-down gate, extended and connected to drain-tank. A io-inch Crane back-pressure valve is placed in line of main exhaust to vent. The waste exhaust-pipe, 10 inches in diameter, is continued and carried to the roof, while the heel is tapped for a i ./-inch drip-pipe and fitted with a screw- down valve of Jenkins Brothers' make with " Diamond " trade-mark; the pipe being led back and connected to feed- heater with a swing check-connection. The top of exhaust- pipe has a special exhaust-head or condenser as shown by the illustration. Fig. 123. The drip is carried through a i -inch pipe down to the boiler-room and then to the feed- heater. HIGH OfFICE-B UILDINGS. 273 Blow-off connections are provided from the boilers to the drip-tank, also drips from oil-separator; and from the tank a FIG. 123. AN IMPROVED STKAM-CONDKNSEK ON ROOF. 2-inch vapor-line extends to the roof; also from this tank a drain-pump discharges into the sewer-line. The blow-off pipes of boilers are respectively 2 and 2i- inches for the two 2/4 THE PLANNING AND CONSTRUCTION OF smaller and for the larger. The feed-pipes are i|, \\, and 2 inches, respectively. Pumping Service in flic Central Bank Building. The pumping service includes the following : Two pumps for feeding boilers; One pump from tank to sewer-outlet; One pump for house water-supply; One fire-pump. These are in addition to those pertaining to the Webster system and those required for elevators. The boiler feed-pumps are of the Deane duplex-piston pattern, 6x4x6 inches, with composition piston-rods, and fitted up complete. The drain-pump is similar. The house- supply pump is of like make, but having brass plungers and rods, with /-i-inch steam-cylinders, 4-! inch water-ends, and o-inch stroke. The fire-pump is of the same pattern, with cylinders 10x6x10 inches with brass plungers and rods, extra-large air-vessel, and water-pressure gauge to 250 Ibs. A SYSTKM OF TEMPERATURE REGULATION IN OFFICE- HUILDINGS. The installation of a system of heating in an office-building is alwavs accompanied by a guarantee to warm all rooms to seventy degrees even during the winter months, when the out-door thermometer registers ten or twenty below xero. I'nder this guarantee, the rooms in all exposed corners cannot be kept at a proper temperature without subjecting, at the same time, the more protected portions to excessive heat. What follows ? Fuel-waste and an unhealthfnl and debilitating effect upon the occupants. Then, again, the most watchful janitor or engineer is unable to insure an even temperature in all the rooms at all times. Therefore, sys- tematic regulation of the temperature, placing artificial HIGH OFFICE-BUILDINGS. 275 FK;. 124. THF.KMOSTAT FOR Ti M C\-.K.\ i TKK REC.IM.ATION. 2/6 THE PLANNING AND CONSTRUCTION OF warming of an office-building upon an economic and sani- tary basis, is to be commended. We herewith present the system as used in the Central Bank Building. A thermostat (see Fig. 124) is placed in each room or place to be controlled. It consists of a compound strip, made of brass and steel, and a small double valve. It is pro- vided with an index, whereby it is set to operate at any rea- sonable temperature, and can be so accurately adjusted that FIG. 125. THERMOSTATIC VALVE FOR TEMPERATURE REGULATION. it will operate on a variation in temperature of one degree. The thermometer on the face is merely for the purpose of showing the temperature and testing the accuracy of the regulation. The compound strip of brass and steel contracts and ex- pands as the temperature rises and falls, opening and closing the valve. This controls the flow of compressed air, through a system of concealed pipes, to or from the valves or dampers at the source of heat to be controlled. UK; ii oi-f-icK-BciLDiNGs. 277 The air-compressor is run 1>y steam-pressure, and, being very simple, requires very little attention, it automatically starts when the air-pressure gets below a fixed limit, and stops when it reaches that limit, thus keeping the pressure uniform. The admission of steam to the radiators is controlled by a diaphragm- valve (see Fig. 125). The large umbrella-like top is provided with a flexible diaphragm. When the action of the compound strip opens the double valve in the thermo- stat, the compressed air enters the top above the diaphragm and closes the valve, thereby cutting off the supply. When the room is cooled a degree or so. the action of the thermo- stat is renewed, the How of compressed air is cut oft. while that within the diaphragm-chamber of the valve escapes, al- lowing it to open again, admitting the steam to the radiator. \\ hile radiators are usually placed under outside win- dows and in cold places, it is very important that they work- in conjunction with the thermostats. We have frequently had occasion to change the location of these thermostats on account of dividing large rooms by partitions, so that thev may be in the same room as the radiators. For large rooms, banking-rooms and auditoriums, the "Johnson" system works admirably. REFRIGERATING APPARATTS AND SYSTKM OF COOI.IM; DRIXKIXG-WATER. The common method of supplying water to a large modern building, so tall that water will not How freely to the upper floors from the pressure in the street- mains, is to pump the water to a tank on the roof, or by the pressure-drum system. From this common source of sup- ply water is taken for drinking and for the various uses for which it is required. With the system described below (which w;as used in sev- 2 7 8 THE PLANNING AND CONSTRUCTION OF eral tall office-building's of this city, namely, the American Tract Society, the Bowling Green, and the Metropolitan Life Insurance buildings), the regular supply of drinking- AIRCMAMBCIl I 33 RD FLOOR 2OTH :6TH 12 TH . 8TH 4.TH 1ST BASEMENT *' "" * WAS1 HETURD PIPC MA! < " ~i r** ^ ~ TANK, CONDENSER C 5 AMMONIA RECEIVER, ETC a 1 T> In a FILTERS POMP SEPARATOR Fill. I2f). (iKNKRAI. A R RANI 1K.M KNT OK THK S/VXITARY I) R I N K INC.-WATKR SVSIEM IN A HIGH OKFICE-BUILDI.M;. water taken from the street-mains is cooled to the desired point without the slightest possibility of receiving any im- purity. The illustration. Fig. i 2(>, shows clearly the genera! arrangement of the plant as supplied in the above buildings. HIGH OFFICE-BUILDINGS. 279 The system includes an ammonia compressor. Fig. 127. in which anhydrous ammonia-gas is compressed. The com- pressed gas is then cooled, and condensed in a condenser, and when the pressure is subsequently relieved the ammonia, in expanding, absorbs heat from any surrounding substance, thus producing the refrigerating effect. The refrigerating effect may be utilized by cooling brine and circulating this brine around the compartment to be cooled, or, for a drink- ing-water system, the most convenient way is to place this expansion-coil in the drinking-water tank. The water from this system is delivered to marble foun- tains placed on each of the various floors of the building, and is kept constantly circulating in the supply-pipe. By reason of this system of circulation the water first delivered from any faucet is cold as soon as the faucet is opened, and there is no necessity for any waste of water while waiting for it to run cold. The entire apparatus is very nearly automatic in its action, does not require a special attendant, and running expenses are insignificant. Buildings in process of construc- tion can be equipped at a small expense, so that a plant can be installed at any time. ELEVATOR CALLING-SIGNALS. \Yherever banks of high-duty passenger-elevators are operated in a modern office-building, it becomes of prime importance to provide some means whereby the intending passenger on any floor may signal his desire to go up or down to the operators in the various cars, so that each may be suitably operated. With the present high-class elevator service, now becoming so prominent a feature of such structures, it is of the utmost importance to keep the various elevators running on sched- ule time, and land the passengers at their respective floors with the greatest comfortable speed. Yet every facility must be afforded' the waiting passenger at any intermediate floor 2 SO THE PLANNING AND CONSTRUCTION OF HIGH OfflCE-B L'll.D 1XGS. 281 to avail himself of the elevator service in either direction with the smallest loss of time and with the minimum of exertion on his part. The calling method in vogue in many installa- tions has very serious objections, although it is certainly the acme of simplicity. Aside from the annoyance created by the almost continuous calls of " up " or " down " from the Fi<;. 128. MAIN COMMUTATOR-SWITCH AND CONTROL MAC.NKTS FOR F.I.K- VA i OK CAI.I.IN<;-SH;NAI.S. waiting-passengers at the various floors, the service ren- dered is very poor, particularly with high-speed service. The passenger, in the majority of instances, does not call until the car has proceeded too far to make the floor landing, and, where the operator is sufficiently accommodating, must re- turn. In addition, therefore, to poor service, inefficiency also results, as one of the prime economical requisites of good elevator service is to make quick, exact stops and con- tinuous trips. The use of individual floor-annunciators located in each car. and indicating up and down for each 282 THE PLANNING AND CONSTRUCTION OF floor, operating in conjunction with up-and-down pushes on each landing, eliminates many of the previously mentioned difficulties. Yet there is still an opportunity for confusion in answering the signal, owing to the fact that the signal is received in all cars. In order to meet the exact require- ments such a signal system should only communicate with the nearest up or down car approaching the landing at which Fir,. 129. SWITCH MKCHAMSM ON Top OF ELEVATOR SHAFT FOR CALLING-SIGNALS. the respective button has heen operated. Such a system has just been installed at the new Telephone Building in this city, working in conjunction with multiple-sheave high-duty electric elevator equipment (consisting of three machines). At each floor-landing (see Fig. 131) two ordinary push- contact buttons are neatly mounted on an ornamental block set in the hoistway frame. These buttons are marked " Up " and " Down." and are normally open. The car-signal con- sists of a small colored incandescent lamp, enclosed in an opalescent globe and ornamental holder. This lamp is illu- minated when the car approaches within one floor of the ///(,'// OFF1CE-K U1LD1XGS. 28 one on which the operated button is located, and is auto- matically extinguished shortly after the car has left the floor. These features are adjustable. Should it be inconvenient to stop on receipt of this signal, the operator may push the normally closed circuit button, which prevents the opera- tion of the signal for that particular car, but leaves the others intact. To produce these results a so-called commutator is me- Vic,. 130. DETAILS or COMMUTATOR chanically connected to each sheave mechanism on the top of each hoistway. The commutator consists of a screw- spindle rotated by a chain and sprocket connection with the moving car-cable sheave. On this spindle a nut i-- moved longitudinally, being held from rotation by two diametrically opposite contact-arms. When the spindle revolves in either direction the friction between the nut and the screw-shaft i^ sufficient to carry the former slightly over in the direction of rotation, raising the contact-arm on the opposite side of the contact-blocks, while the other is pressed down on the opposite blocks. One of the commutator devices is fitted 284 THE PLANNING AND CONSTRUCTION OF with a set of controlling magnets, which are connected to the contact-buttons and control the light contacts. All con- tacts on one side are for down signals, those on the other for up. The magnets are similarly arranged. The dia- grams show the arrangement and connections. On each side of the screw-spindle is a continuous-contact strip, followed by a parallel series of release-magnet and car- signal light contacts. All of the various contacts are in mul- tiple. The arrangement of the magnets will readily be seen from the illustration. Fig. 130. Their function is to control the light signal-contacts. The upper row of magnets on each side are connected and controlled by the landing- pushes, those on one side being controlled by the up mish and those on the other by the down. \Yhen any one of these magnets is energized by the completion of the circuit through the button, it attracts its armature and thereby re- leases the armature of the lower magnet, to which a switch- arm is attached, which, dropping into a mercury-cup, con- nects the corresponding light contact. This mercury-switch is held closed by its own weight, and remains in this position until the release-magnet is energized, acting on its armature and raising the contact-arm out of the mercury-cup. As the car moves up or down the shaft the contact-brushes on one or the other of the arms are brought into connection with the various release-magnet and light contacts. When the light contact, whose circuit has been closed by the mag- netically operated mercury-switch, is connected to the moving contact-arm, the car-light circuit is closed through the lamp in the car and signals the operator to stop. \Yhen the contact-arm leaves this contact-block the light is ex- tinguished, and the mercury-switch is opened when the con- tact-arm comes in connection with the next block, on a line with which is also the release-magnet contact of the pre- HIGH OFFICE-BUILDINGS. 285 viously operated mercury-switch. The connection of the latter circuit energizes the release-magnet, and allows the switch-operating armature to return to its normal position. In the diagram are shown an additional row of contacts ad- jacent to the car-light contacts on each side. These control lights are located on the landings at each elevator-shaft, and Fii;. 131. DIAGRAM OK WIRING CONNECTIONS FOR ELEVATOR CAL.I.IM.- SIGNALS. indicate whether that particular car is going up or down. This feature is omitted in the Telephone lUiilding plant. If a button should be pushed, and the first approaching car either up or down be fully loaded or otherwise unable to take on the passenger, the operator pushes the button in the car which is connected in series with the release-magnet, and this prevents the completion of the circuit when the terminal comes in contact with the arm. The next approaching car will, however, receive this signal, as the switching' magnet remains closed until the release-magnet is energized. It will be noted that all the release-magnet and light terminal- 286 THE PLANNING AND CONSTRUCTION OF are in multiple, so that one set of up-and-down magnets may control any number of floor-pushes and commutators. In this installation there are twelve floors and three commuta- tors. For supplying current to this signal system a small motor generator is used, taking current from the i lo-volt lighting circuit of the building, and reducing to about 10 volts, at which it is supplied through the commutator-terminals and landing-pushes to the closing and releasing magnets. It will be noted that this part of the apparatus is entirely free from the car-signal lights, which are supplied from the i lo-volt line, which is connected from a central' point in the hatch- way to the car, the two-car release-wires from each com- mutator being carried in the same cable. Tlic Electrical ITorhl, Sept. 4, 1896, HIGH OFFICE-BUILDINGS. 287 CHAPTER IX. PLUMBING AND DRAINAGE. THE rules and regulations governing plumbing in New York City have at last been completed, the ground being so well covered that they will not be materially changed for years to come. On several occasions we have had plans passed and approved, and yet before completion of the work at the building have been notified that it could not proceed on account of a change in the law covering the particular part objected to; the work being allowed to go on upon our stating that the plans had been approved under the old law. We believe the present law excellent, and herewith pub- lish the rules and regulations complete, knowing that for reference they will be valuable to architects and builders outside of as well as in the city of Xew York. PLVMBIXG RULES AND REGULATIONS ACCORDING TO TILE NEW YORK BUILDING LAW IN EFFECT JANUARY I, 1897. Drawings and triplicate descriptions on forms furnished by the Department of Buildings for all plumbing and drain- age shall be filled in with ink and filed by the owner, archi- tect, or plumber in the said Department. And the said plumbing and drainage shall not be com- menced or proceeded with until said drawings and descrip- tions shall have been so filed and approved by the Superin- tendent of Buildings. 288 THE PLANNING AA'D CONSTRUCTION OF No modification of the approved drawings and descrip- tions will be permitted unless either amended drawings and triplicate descriptions, or an amendment to the original drawings and descriptions, covering the proposed change or changes, are so filed and approved by the Superintendent of Buildings. It shall not be lawful to do said plumbing and drainage except pursuant to said approved drawings and descriptions or approved amendments thereof. Repairs or alterations of plumbing and drainage may be made without the filing and approval of drawings and de- scriptions in the Department of Buildings. But said repairs or alterations shall not be construed to include cases where new vertical and horizontal lines of soil, waste, vent, or leader pipes are proposed to be used. Notice of said repairs or alterations shall be given to the said Department, before the same are commenced, in all cases, except where leaks are stopped or obstructions are re- moved. Said notice shall consist of a description in writing of the work to be done, of the location of the property where the same is executed, and of the names and addresses of the owner and of the plumber. Said notice shall not, however, be required when repairs or alterations are ordered by the Board of Health for sani- tary reasons. Said repairs and alterations shall comply in all respects with the weight, quality, arrangement, and venting of the rest of the work in the building. The plans must be drawn to scale in ink on cloth, or they must be cloth prints of such scale drawings, and shall con- sist of such floor plans and sections as may be necessary to show clearly all plumbing work to be done, and must show HIGH OFFICE -BUILD INGS. 289 partitions and the method of ventilating" water-closet apart- ments. Written notice must be given to the Department of Buildings by the plumber when any work is begun, and from time to time when any work is ready for inspection. No part of the work shall be covered until it has been examined, tested, and approved by the Inspector. Definition of Terms. The term " private sewer " is ap- plied to main sewers that are not constructed by and under the supervision of the Department of Public Works or the Department of Street Improvements of the Twenty-third and Twenty-fourth Wards. The term " house-sewer " is applied to that part of the main drain or sewer extending from a point two feet outside of the outer face of the outer front vault or area wall to its connection with the public sewer, private sewer, or cesspool. The term " house-drain " is applied to that part of the main horizontal drain and its branches inside the walls of the building and extending to and connecting with the house- sewer. The term " soil-pipe " is applied to any vertical line of pipe, extending through roof, receiving the discharge of one or more water-closets, with or without other fixtures. The term " waste-pipe " is applied to any pipe, extend- ing through roof, receiving the discharge from any fixtures except water-closets. The term " vent-pipe " is applied to any special pipe pro- vided to ventilate the system of piping and to prevent trap Mphonage and back-pressure. I. Materials and Workmanship. All materials must be of the best quality, free from defects; and all work must be executed in a thorough, workmanlike manner. All cast-iron pipes and fittings must be uncoatecl. sor.nd. 290 THE PLANNING AND CONSTRUCTION OF cylindrical, and smooth, free from cracks, sand-holes, and other defects, and of uniform thickness and of the grade known in commerce as extra-heavy. Pipe, including the hub, shall weigh not less than the fol- lowing average weights per lineal foot : Diameters. Weights per Lineai Fot. 2 inc 3 4 5 7 S 10 I 2 hes 5s poi 94 13 i7 20 27 33 i 45 *j inds. The size, weight, and maker's name must be cast on each length of the pipe. All joints must be made with picked oakum and molten lead, and be made gas-tight. Twelve ( 12) ounces of fine, soft pig lead must be used at each joint for each inch in the diameter of the pipe. All wrought-iron and steel pipe must be equal in quality to " Standard," and be properly tested by the manufacturer. All pipe must be lap-welded. Xo plain back or uncoated pipe will be permitted. After January i. 1^97, wrought-iron and steel pipe must be galvani/.ed, and each length must have the weight per foot and maker's name stamped on it. Fittings for vent-pipes on wrought-iron or steel pipes may be the ordinary cast or malleable steam and water fit- tings. Fittings for waste or soil pipes must be the special, extra- heavv cast-iron recessed and threaded drainage fittings, with HIGH OFFICE-K U1LDINGS. 291 smooth interior waterway and threads tapped, so as to give a uniform grade to branches of not less than j of an inch per foot . All joints to be screwed joints made up with red lead, and the burr formed in cutting must be carefully reamed out. Short nipples on wrought-iron or steel pipe where the unthreaded part of the pipe is less than one and one-half (H) inches long must be of the thickness and weight known as " extra heavy " or " extra strong." The pipe shall be not less than the following average thickness and weight per lineal foot : Thicknesses. Weights per Lineal Foot. inch 2i 3 3* 4 10 i i .14 inc 15 hes. 2 3 68 pou 6 1 nds. . 20 5 74 .21 7 54 23 9 10 00 66 24 12 34 25 . 28 M 18 50 76 3 3 2 23 28 27 18 34 3f> 33 4 98 All brass pipe for soil, waste, and vent pipes and solder- nipples must be thoroughly annealed, seamless, drawn brass tubing, of standard iron-pipe gauge. Connections on brass pipe and between brass pipe and traps or iron pipe must not be made with slip-joints or couplings. Threaded connec- tions on brass pipe must be of the same size as iron-pipe threads for same size of pipe and be tapered. 292 THE BUILDING AND CONSTRUCTION OF The following average thickness and weights per lineal foot will be required : Diameters. Thicknesses. Weights per Lineal Foot. \\ inc 2 2* 3 3i 4 4* 5 6 . 14 inc 15 .20 .21 .22 23 .24 25 .28 hes. 3 6 7 9 n 13 15 19 84 pou 82 08 92 54 29 08 37 88 n.ds. Brass ferrules must be best quality, bell-shaped, extra- heavy cast brass, not less than four inches long and two and one-quarter inches, three and one-half inches and four and one-half inches in diameter, and not less than the following weights : Diameters. Weights. 2\ inches r pound o ounces. 3! " i " 12 4^ " 2 pounds 8 " One and one-half inch ferrules are not permitted. Soldering-nipples must be heavy cast brass or of brass pipe, iron-pipe size. When cast, they must be not less than the following weights : Diameters. Weights. o pounds 8 ounces. " 14 1 pound 6 ounces. 2 pounds o ounces. 3 " 8 - HIGH OFFICE-BUILDINGS. 293 Brass screw-caps for clean-outs must be extra heavy, not less than one-eighth of an inch thick, and must have a flange of not less than three-sixteenths of an inch thick. The screw-cap must have a solid square or hexagonal nut not less than one (i) inch high, with a least diameter of one and one- half (i4) inches. The body of the clean-out ferrule must at least equal in weight and thickness the calking ferrule for the same size of pipe. Where clean-outs are required by rules and by the approved plans the screw-cap must be of brass. The engaging parts must have not less than six (6) threads of iron-pipe size and tapered. Clean-outs must be of full size of the trap up to four (4) inches for large traps. The use of lead pipe is restricted to the short branches of the soil, waste, and vent pipes, bends, and traps, roof connec- tion of inside leaders and flush-pipes. All lead, waste, soil, vent, and flush pipes must be of the best quality drawn pipe of the quality known in commerce as '' D," and of not less than the following weights per lineal foot : Diameters. Weights per Lineal hoot. ij-inch (for flush pipes only) 2\ pounds. i| inches 3 2 " 4 3 " 6 4 and 4\ inches 8 All lead traps and bends must be of the same weights and thicknesses as their corresponding pipe branches. Sheet lead for roof-flashings must be six-pound lead and must ex- tend not less than six (6) inches from the pipe, and the joint made water-tight. Copper tubing when used for inside leader roof connections must be seamless drawn tubing 294 THE PLANNING AND CONSTRUCTION OF not less than 22 gauge, and when used for roof-flashings must be not less than 18 gauge. II. General Plan of Plumbing and Drainage approved by the Superintendent of Buildings. Each building must be separately and independently connected with the public or a private sewer. The entire plumbing and drainage system of every build- ing must be entirely separate and independent of that of any other building. Every building must have its sewer connections directly in front of the building unless permission is otherwise granted by the Superintendent of Buildings. Where there is no sewer in the street or avenue, and it is possible to construct a private sewer to connect with a sewer in an adjacent street or avenue, a private sewer must be con- structed. It must be laid outside the curb, under the roadway of the street. Cesspools and privy vaults will be t permitted only after it has been shown to the satisfaction of the Superintendent of Buildings that their use is absolutely necessary. \Yhen allowed they must be constructed strictly in ac- cordance with the terms of the permit issued by the Superin- tendent of Huildings. Cesspools will not be permitted under any circumstances for tenement and lodging houses. Cesspools will not be al- lowed outside the frame-building district. As soon as it is possible to connect with a public sewer the owner must have the cesspool and privy vault emptied, cleaned and disin- fected, and filled with fresh earth, and have a sewer connec- tion made in the manner herein prescribed. Old house-sewers can be used in connection with the new buildings or new plumbing only when they are found on ex- HIGH OFFICE-BUILDINGS, 295 animation by the Plumbing' Inspector to conform in all re- spects to the requirements governing new sewers. When a proper foundation, consisting of a natural bed of earth, rock, etc., can be obtained, the house-sewer can be of earthenware pipe. Where the ground is made or tilled in. or where the pipes are less than three feet deep, or in any case where there is danger of settlement by frost or from any other cause, and when cesspools are used, the house-sewer must be of extra- heavy cast-iron pipe with lead-calked joints. The house-sewer and house-drain must be at least 4 inches in diameter where water-closets discharge into them. Where rain-water discharges into them, the house-sewer and the house-drain up to the leader connections must be in accordance with the following table : Diameter. Fall J4 Inch per Foot. Kail \- Inch per Foot. inches ...... 5,000 square feet. 7,5<->o square feet of drainage of area. " ...... I 6,900 10,300 " ...... 9.IOO 13,600 " ...... 1 1, 600 17,400 Xo steam-exhaust, boiler blow-off, or drip pipe shall be connected with the house drain or sewer. Such pipes must first discharge into a proper condensing-tank, and from this a proper outlet to the house-sewer outside the building must be provided. In low-pressure steam systems the condens- ing-tank may be omitted, but the waste connection must be otherwise as above required. The house-drain and its branches must be of extra-heavy cast iron when under ground, and of extra-heavy cast iron or galvanized tarred or asphalted wrought iron or steel when above ground. The house-drain must properly connect with the house- 296 THE PLANNING AND CONSTRUCTION OF sewer at a point two feet outside of the outer front vault or area wall of the building. An arched or other proper open- ing must be provided for the drain in the wall to prevent damage by settlement. The house-drain and sewer must be run as direct as pos- sible, with a fall of at least one-quarter inch per foot, all changes in direction made with proper fittings, and all con- nections made with Y branches and one-eighth and one-six- teenth bends. If possible the house-drain must be above the cellar-floor. The house-drain must be supported at intervals of 10 feet by 8-inch brick piers or suspended from the floor-beams or be otherwise properly supported by heavy iron pipe-hangers at intervals of not more than 10 feet. The use of pipe-hooks for supporting drains is pro- hibited. An iron running trap must be placed on the house-drain near the wall of the house, and on the sewer side of all con- nections, except a drip-pipe, where one is used. If placed outside the house or below the cellar-floor it must be made accessible in a brick manhole, the walls of which must be 8 inches thick, with an iron or flagstone cover. \Yhen outside the house it must never be less than 3 feet below the surface of the ground. The house-trap must have two clean-outs with brass screw-cap ferrules calked in. A fresh-air inlet must be connected with the house-drain just inside of the house-trap. The fresh-air inlet will be of extra-heavy cast iron where under ground. \Yhere possible it will extend to the outer air and finish with a return bend at least one foot above grade, and 15 feet away from any window or furnace cold-air box. \Yhen this arrangement is not possible, the fresh-air inlet must open into the side of a box not less than 18 inches square placed below the sidewalk. HIGH OFFICE-BUILDINGS, 297 at the curb. The bottom of the box must be 18 inches be- low the under side of the fresh-air inlet-pipe. The box may be of cast iron, or it may be constructed with 8-inch walls of brick or flagstone laid in hydraulic cement. The box must be covered by a flagstone fitted with removable metal grat- ing, leaded into the stone, having openings equal in area to the area of the fresh-air inlet and not less than one-half inch in their least dimension. The fresh-air inlet must be of the same size as the drain up to four (4) inches; for five (5) inch and six (6) inch drains it must be not less than four (4) inches in diameter; for seven (7) inch and eight (8) inch drains not less than six (6) inches in diameter; and for larger drains not less than eight inches in diameter. All yards, courts, and areas must be drained. Tenement- houses and lodging-houses must have their yards, areas, and courts drained into the sewer. These drains, when sewer-connected, must have connec- tions not less than three inches in diameter. They should, if possible, be controlled by one trap the leader-trap if pos- sible. Leader-pipes must be sewer-connected if possible. All buildings shall be kept provided with proper metallic leaders for conducting water from the roofs in such manner as shall protect the walls and foundations of said buildings from injury. In no case shall the water from said leaders be allowed to flow upon the sidewalk, but the same shall be con- ducted by pipe or pipes to the sewer. If there be no sewer in the street upon which such buildings front, then the water from said leader shall be conducted by proper pipe or pipes below the surface of the sidewalk to the street gutter. Inside leaders must be made of cast iron, wrought iron, or steel, with roof connections made gas and water tight by means of a heavy lead or copper drawn tubing wiped or 298 THE PLANNING AND CONSTRUCTION Of- soldered to a brass ferrule or nipple calked or screwed into the pipe. Outside leaders may be of sheet metal, but they must connect with the house-drain by means of a cast-iron pipe extending vertically five feet above the grade level. Leaders must be tapped with cast-iron running traps so placed as to prevent freezing. Rain-water leaders must not be used as soil, waste, or vent pipes, nor shall any such pipe be used as a leader. Cellar-drains will be permitted only where they can be connected to a trap with a permanent water-seal. Subsoil drains should discharge into a sump or receiving- tank, the contents of which must be lifted and discharged into the drainage system above the cellar-bottom by some approved method. \Yhere directly sewer-connected they must be cut off from the rest of the plumbing system by a brass flap- valve on the inlet to the catch-basin, and the trap on the drain from the catch-basin must be water-supplied, as required for cellar-drains. Foundation-walls must, where required, be rendered im- pervious to dampness bv the use of coal-tar, pitch, or asphal- tum. Full-size Y and T branch fittings for hand-hole clean-outs must be provided where required on house-drain and ils branches. All iron traps for house-drain, yard, and other drains and leaders, must be running traps with hand-hole clean-outs of full size of the traps when same are less than five (5) inches. All traps under ground must be made accessible by brick- manholes with proper covers. Soil and }\ 7 astc Pipe Lines. All main soil, waste, or vent pipes must be of iron, steel, or brass. \Yhen they receive HIGH OFFICE-BUILDINGS. 299 the discharge of fixtures on any lloor above the first they must be extended in full calibre at least one foot above the roof coping, and well away from all shafts, windows, chim- neys, or other ventilating openings. When less than four inches in diameter, they must be enlarged to four inches at a point not less than one foot below the roof surface by an increaser not less than nine (9) inches long. No caps, cowls, or bends shall be affixed to the top of such pipe. In tenement-houses and lodging-houses wire baskets must be securely fastened into the opening of each pipe that is in an accessible position. All pipes issuing from extensions or elsewhere, which would otherwise open within 30 feet of the window of any building, must be extended above the highest roof and well awav from and above all windows. The arrangement of all pipe-lines must be as straight and direct as possible. Offsets will be permitted only when una- voidable. Xecessary offsets above the highest fixture branch must not be made at an angle of less than 45 degrees to the hori- zontal. All pipe-lines must be supported at the base on brick piers or by heavy iron hangers from the cellar ceiling-beams and along the line by heavy iron hangers at intervals of not more than ten feet. All pipes and traps should, where possible, be exposed to view. They should always be readily accessible for inspec- tion and repairing. Xo trap shall be placed at the foot of main soil and waste pipe lines. The sixes of soil and waste pipes must be not less than those given in the following table : 300 THE PLANNING AND CONSTRUCTION OF Main soil-pipe, 4 inches in diameter; main waste-pipe, 2 inches in diameter; branch soil-pipe, 4 inches in diameter; branch waste for laundry-tubs, 2 inches in diameter; branch waste for kitchen-sink, 2 inches in diameter; soil-pipe for water-closets on five or more floors, 5 inches in diameter; waste-pipes for kitchen-sinks on five or more floors, 3 inches in diameter; main soil-pipe for three-family tenement-houses exceeding three stories, 4 inches in diameter. In every building where there is a leader connected to the drain, if there are any plumbing fixtures, there must be at least one four (4) inch pipe extending above the roof for ven- tilation. Soil and waste pipes must have proper Y branches for all fixture connections. Branch soil and waste pipe must have a fall of at least one-quarter inch per foot. Short T Y branches will be per- mitted on vertical lines only. Long one-quarter bends and long T V's are permitted. Short one-quarter bends and double hubs, short roof-increasers, and common offsets are prohibited. All traps must be protected from siphonage and back- pressure, and the drainage system ventilated by special lines of vent-pipes. All vent-pipe lines and main branches must be of iron, steel, or brass. They must be increased in diameter and ex- tended above the roof as required for waste-pipes. They may be connected with the adjoining soil or waste line well above the highest fixture, but this will not be permitted when there are fixtures on more than six floors. All offsets must be made at an angle of not less than forty-five degrees to the horizontal, and all lines must be connected at the bottom with a soil or waste pipe or Ihe HIGH OFFICE-BUILDINGS. 3OI drain in such a manner as to prevent the accumulation of rust scale. Branch vent-pipes should be kept above the top of all connecting fixtures, to prevent the use of vent-pipes as soil or waste pipes. They will not be permitted lower than the outlet of the highest fixture in the group. Branch vent- pipes should be connected as near to the crown of the trap as possible. The' sizes of vent-pipes throughout must not be less than the following : For main vents and long branches, two inches in diam- eter; for water-closets on three or more floors, three inches in diameter; for other fixtures on less than seven floors, two inches in diameter; three-inch vent-pipe will be permitted for less than nine stories; for more than eight and less than sixteen storie's, four inches in diameter; for more than fifteen and less than twenty-two stories, five inches in diameter ; for more than twenty-one stories, six inches in diameter, branch vents for traps larger than two inches, two inches in diameter; traps two inches or less, one and one-half inches in diameter. For fixtures other than water-closets and slop-sinks and for more than eight (8) stories, vent-pipes may be one ( i ) inch smaller tha-n above stated. Xo sheet metal, brick, or other flue shall be used as a \ cnt-pipe. Earthenware traps for water-closets and slop-sinks must be ventilated from the branch soil or waste pipe just below the trap, and this branch vent-pipe must be so connected as to prevent obstruction, and no waste-pipe connected be- tween it and the fixture. Earthenware traps must have no vent-horns. 3O2 THE PLANNING AND CONSTRUCTION OF Every fixture must be separately trapped by a water-scal- ing trap placed as close to the fixture outlet as possible. A set of wash-trays may connect with a single trap, or into the trap of an adjoining sink, provided both sink and tub-waste outlets are on the same side of the waste-line, and the sink is nearest the line. When so- connected the waste- pipe from the wash-trays must be branched in below the water-seal. The discharge from any fixture must not pass through more than one trap before reaching the house-drain. All traps must be well supported and set true with re- spect to their water-levels. All traps must have a water-seal of at least one and one- half inches. Xo mason's, cesspool, bell. pot. bottle, or D trap will be permitted, nor any form of trap that is not self-cleaning, nor that has interior chamber or mechanism, nor any trap, ex- cept earthenware ones, that depend upon interior partitions for a seal. All fixtures, other than water-closet and urinals, must have strong metallic strainers or bars over the outlets to pre- vent obstruction of the waste-pipe. All exposed or accessible traps, except water-closet traps, must have brass trap-screws for cleaning the trap, placed on the inlet side, or below the water-level. Traps for water-closets must not be less than four inches in diameter: traps for slop-sinks must not be less than two inches in diameter; traps for kitchen-sinks must not be less than two inches in diameter; traps for wash-trays must not be less than two inches in diameter; traps for urinals must not be less than two inches in diameter; traps for other fix- tures must not be less than one and one-half inches in diam- eter. HIGH OFFICE-BUILDINGS. 303 Overflow-pipes from fixtures must in all cases be con- nected on the inlet side of traps. All earthenware traps must have heavy brass floor-plates soldered to the lead bends and bolted to the trap flange, and the joint made gas-tight with red or white lead. The use of rubber washers for floor connections is prohibited. Earthenware water-closets must be set on marble or slate- in all new work, and when it is not impossible to use it be- cause of water-pipes or other obstructions, in all alterations of old work. Safe and refrigerator waste-pipes must be of galvanized iron, and be not less than one ( i ) inch in diameter, with lead branches of the same size, with strainers over the inlets se- cured by a bar soldered to the lead branch. Safe waste-pipes must not connect directly with any part of the plumbing 1 system. Safe waste-pipes must either discharge over an open. water-supplied, publicly placed, ordinarily used sink, placed not more than three and one-half feet above the cellar-floor, or thev max discharge upon the cellar-floor. The safe waste-pipe from a refrigerator cannot discharge upon the ground or floor. !t must discharge over an ordi- nary portable pan, or over some properly trapped water-sup- plied sink, as above. The branches on vertical lines must be made by Y fit- tings, and be carried up to the safe with as much pitch as possible. Lead safes must be graded and neatly turned over beve! strips at their edges. \Yhere there is an offset on a refrigerator waste-pipe in the cellar, there must be clean-outs to control the horizontal part of the pipe. In tenement-houses and lodging-houses the refrigerator .304 THE PLANNING AXD CONSTRUCTION OF waste-pipes must extend above the roof, and must not be larger than one and one-half inches, nor the branches smaller than one and one-quarter inches. These branches must have full-size accessible traps. Refrigerator waste-pipes, except in tenement-houses, and all safe waste-pipes, must have brass flap-valves at their lower ends. Fixtures. In tenement-houses, lodging-houses, factories, and workshops the water-closets must be set on marble, slate, or tile, and the back and ends of the water-closet apart- ment must be made water-proof with some similar non- absorbent material. The closets must be set open and free from all inclosing woodwork. Where water-closets will not support a rim seat, the seat must be supported on galvanized-iron legs, and a drip-tray must be used. The general water-closet accommodations for a tenement MM" lodging house cannot be placed in the cellar, and no water-closet can be placed outside of the building. In tenement-houses and lodging-houses there must be one water-closet on each floor, and when there is more than one family on a floor there will be one additional water-closet for every two additional families. In lodging-houses where there are more than 15 persons on any floor there must be an additional water-closet on that floor for every 15 additional persons or fraction thereof. In all other sewer-connected occupied buildings there must be at least one water-closet, and there must be addi- tional closets so that there will never be more than 15 per- sons per closet. In tenement-houses and lodging-houses the water-closet .and urinal apartments must have a window opening to the HIGH OFFICE-BUILDINGS. 305 -inter air, or to a ventilating-shaft, not less than 10 s(jtiarc feet in area. In all buildings the outside partition of such apartment must extend to the ceiling <>r he independently ceiled over, and these partitions must he air-tight, except at the bottom of the door, which must be cut away or provided with open- ings tc promote ventilation. The otitside partitions must in- clude a window opening to outer air on the lot whereon the building is situated, or some other approved means of venti- lation must be provided. When necessary to properly light such apartments, the upper part of the partitions must be made of glass. The interior partitions of such apartments must be dwarf partitions. Pan, valve, plunger, and other water-closets having an unventilated space, or whose walls are not thoroughly washed at each discharge, will not be permitted. .Ml water-closets must have earthenware flushing rim bowls. " Pipe wash " bowls or hoppers will not be per- mitted Long hoppers will not be permitted except where there is an exposure to frost. Where water-closet or other fixture traps are of iron they must be porcelain lined. Drip-trays must be enamelled on both sides and secured in place. \Yater-closets and urinals must never be connected di- rectly with or flushed from the water-supply pipes. Water-closets and urinals must be Hushed from a sepa- rate cistern, the water from which is used for no other pur- pose. The overflow of cisterns may discharge into the bowls of the closet, but in no case connect with any part of the drain- age system. 3O6 THE PLANNING AND CONSTRUCTION OF Iron water-closet cisterns and automatic urinal cisterns are prohibited. The copper lining of water-closet and urinal cisterns must be not lighter than ten (10) ounce copper. \\~ater-closet flush-pipes must not be less than one and one-fourth inches, and urinal flush-pipes one (i) inch in di- ameter, and if of lead must not weigh less than two and one- half pounds and two pounds per lineal foot. Flush coup- lings must be of full size of the pipe. Latrines, trough water-closets, and similar appliances may be used only on written permit from the Superintendent of Buildings, and must be set and arranged as may be re- quired by the terms of the permit. All urinals must be constructed of materials impervious to moisture that will not corrode under the action of urine. The floor and walls of the urinal apartments must be lined with similar non-absorbent and nan-corrosive material. The platforms or treads of urinal stalls must never be connected independently to the plumbing system, nor can they be connected to any safe waste-pipe. Iron troughs or urinals must be enamelled or galvanized. In tenement-houses and lodging-houses sinks must be en- tirely open, on iron legs or brackets, without any inclosing woodwork. Wooden wash-tubs are prohibited. Cement or artiiicial- stone tubs will be permitted, provided the same be made in the following manner, to wit: The cement or artificial stone to be one part good Portland cement to not more than three parts crushed or broken granite, gneiss, or equally hard stone, broken to a size not larger than will go through a i -inch ring, well-tamped: each tub to be branded with the owner's name and with the absolute mixture stamped on said tub. samples of which shall be hied and approved by this HIGH OFF- ICE-BUILD INGS. 3O/ Department ; each compartment of the tub shall have a separate bottom outlet with a through-and-through fitting, and overflows shall be external to the tub. Xo tubs made with cinder, ashes, or Rosendale cement, or any other materials than above specified, will be allowed. All water-closets and other plumbing fixtures must be provided with a sufficient supply of water for Hushing, to keep them in a proper and cleanly condition. When the water-pressure is not sufficient to supply freely and continuously all fixtures, a house-supply tank must be provided, of sufficient size to afford an ample supply of water to all fixtures at all times. Such tanks must be supplied from the pressure or by pumps, as may be necessary; when from the pressure, ball-cocks must be provided. If water-pressure is not sufficient to fill house-tank, power-pumps must be provided for filling them in tenement - houses, lodging-houses, factories, and workshops. Tanks must be covered so as to exclude dust, and must be so located as to prevent water contamination by gases and odors from plumbing fixtures. House-supply tanks must be of wood or iron, or of wood lined with tinned and planished copper. House-tanks must be supported on iron beams. The overflow-pipe should discharge upon the roof where possible, and in such cases should be brought down to within six ((>) inches of the roof, or it must be trapped and dis- charged over an open and water-supplied sink not in the same room, not over 3! feet above the floor. In no case shall the overflow be connected with any part of the plumb- ing system. Emptying-pipes for such tanks must be provided and be discharged in the manner required for overflow-pipes, and mav be branched into overflow-pipes. 3O8 7 HE PLANNING A\D CONSTRUCTION OF Xo service-pipes or supplying-pipes should be run, and no tanks, flushing-cisterns, or water-supplied fixtures should be placed, where they will be exposed to frost. Where so placed they shall be properly packed and boxed in such a manner as to prevent freezing, and to the satisfac- tion of the plumbing inspector. The entire plumbing and drainage system within the building must be tested by the plumber, in the presence of a plumbing inspector, under a water or air test, as directed. All pipes must remain uncovered in every part until they have successfully passed the test. The plumber must se- curely close all openings as directed by the inspector of plumbing. The use of wooden plugs for this purpose is pro- hibited. The water test will be applied by closing the lower end of the main house-drain and filling the pipes to the highest opening above the roof with water. If the drain or any part of the system is to be tested separately, there must be a head of water at least six (6) feet above all parts of the work so tested, and special provision must be made for including all joints and connections in at least one test. The air test will be applied with a force-pump and mer- cury-column under ten pounds pressure equal to 20 inches of mercury. The use of spring-gauges is prohibited. After the completion of the work, when the water has been turned on and the traps filled, the plumber must make a peppermint or smoke test in the presence of a plumbing in- spector, and as directed by him. The material and labor for the tests must be furnished by the plumber. Where the peppermint test is used two ounces of oil of peppermint must be provided for each line up to five stories and basement in height, and for each additional five HIGH OfiFICE-B L'JLDIXGS. 309 stories or fraction thereof one additional ounce of pepper- mint must he provided for each line. Y-5 7 FH;. 132. DIAIJRAM OK WASII- HASIN I'iri; CONNKC no\. 133. DIAUKAM CK Pi I'K CDNNKC- ION KOK MK.N'S TOII.KT ROOMS. ig and Drainage in the Central Bank Rnihling. The plntnhino- work in the C'entrr;! T.ank lUiiltlino- is finished 310 THE PLANNING AND CONSTRUCTION OF according to the rules and regulations of the latest New York law. There are nine lines of wash-basins, connected to the up and down pipes as shown by the drawing, Fig. 132. The waste and vent lines to these basins are each 3 inches in di- ameter, while the branches are i^ inches, the total number of basins throughout the building being 358. By referring to the typical floor-plan of the building in another chapter, it will be noticed that there are two lines of toilet-rooms, the men's being placed on every floor and the women's on the fifth, tenth, and fifteenth. This arrangement requires two lines of soil-pipes. The illustration. Fig. 133, shows the pipes for the men's toilets, and the plan. Fig. 134, shows the position of all the fixtures. The women's toilets require a 5-inch diameter soil and 4-inch vent; the men's toilets, a 6-inch soil and 5-inch vent for closets, and a 4-inch vent for other fixtures. All urinals, closets, and sinks have 2-inch branch vents. In addition to the wash-basins already mentioned, there are 95 closets. 33 urinals, and 17 sinks. The water-closets throughout are porcelain siphon closets, furnished with quartered-oak seat and flap, attached to the bowl. The vents from bowl water connection to cistern are all nickel-plated, and each closet has a i {-inch nickel-plated brass flush-pipe, with a celluloid pull. The cisterns are made of wood, and are lined inside with i6-oz. tinned copper and outside with marble. The urinals are long-lipped white earthenware, with nickel-plated outlet connections, supplied with self-closing cocks, wasting through a 2-inch " S " lead trap and lead waste-pipe to the galvanized wrought-iron outlet pipe. The wash-bowls have 11 x 13 inch centre outlets, ivorv- tinted earthenware bowls with earthenware overflow, and ///(/// OFF1CE-BU1LD1\GS. 311 nickel-plated ])lug chain and stay. The water is supplied through self-closing cocks, and wastes through a i i-inch nickel-plated brass trap and pipe. The slabs are supported on nickel-plated offset legs and nickelled apron-holders. On supply-pipe below basin there is placed a i-inch angle shut- off valve. In offices basins are supplied with cold water; in toilet-rooms, with hot and cold water. The slop-sinks are of 18x24x10 inch enamelled iron, and are supplied with patent overflow, brass plug and Fi<;. 134. -Pi. AN OK .MEN'S TOII.KT ROOM, CENTRAL BANK Hrn.niM.. strainer, with hot and cold water through ;'-inch self-closing bibb-cocks, placed high enough to clear a pail. The waste is through a ^-inch cast-iron enamelled trap. The house-drain which connects with the main sewer on I 'earl Street is 8 inches in diameter, of cast iron, and carried to inside of vault line. From this point an inches in thickness that brackets for holding tracks be firmly bolted to the brick wall, both sides, by expansion bolts, the tracks to be placed at an incline not less than ;' to ] inch to the foot, and at such a height that the door when closed will rest firmly on the sill. which is to project ^\ inches bevond the tace ot the wall. ( )utside shutters which arc generally il;iced at the win- dows of three or four stories above the adjoining property 322 THE PLANNING AND CONSTRL'CTIOX OF are made of ^ x 2] in. wrought-iron frames, with cross-bars of the same material, and covered with Xo. 16 crimped sheet iron, being suspended from cast-iron shutter-eyes built in when the wall is constructed. Doors and shutters of the same style are provided to bulkheads and roof-houses. Bulkheads on Roof. These roof-houses are invariably constructed of steel tees, channels, 1 beams, and angles placed from 3 to 5 feet apart and tilled in between with 3-inch hollow terra-cotta blocks, plastered on the inside and cov- ered on the outside with metal clapboarding either of gal- vanized iron or copper. Hanging Ceiling in Boiler-room. The ceiling over the boilers of the Central. Bank 'Building is formed by 2 >' 2 in. tees, set 25 inches on centres, suspended from the floor- beams by iron straps 12 in. below. a.nd filled in between on all sides with asbestos blocks, an air-cushion being thus pro- vided to keep the heat from the floor above. False Furring. False furring, made either of wire cloth simply, or of light steel angles and tees cavered with wire cloth, will be required to a great extent in such places as halls, corridors, vestibules, and all large rooms where col- umns, girders, and beams 'cannot be covered with terra-cotta 1 ilocks or masonry. Skylights and Sheet-metal l]*ork. The work under this head includes skylights, bulkhead coverings, louvres, cor- nices, and flashing. The skylights over elevator shafts, stairways, etc.. arc generally made with light steel tee ribs 2 o.r 3 inches in depth, placed u to. 16 inches on centres, and covered with galvanized metal or copper. The skylights have condensa- tion-gutters on the under side of ribs, and caps on top to hold d< >wn the s/lass. FIG. 139. ORNAMENTAL ELEVATUK CAR, " CKNTKAI. HANK H HIGH OFFICE-BUILDINGS. 325 If the bulkhead is of sufficient height, the ventilating louvres are placed in its side instead of in the skylight. If copper is used, 16 oz. weight per foot is the proper gauge. The same gauge is used for all roof-flashings. Skylights which are placed at the bottom of light-courts or where necessary are protected by galvanized-wire screens of Xo. 13 gauge and one-inch mesh. The main cornices of our better buildings at this writing have adopted terra-cotta or stone, instead of metal. (See remarks upon Terra-cotta.) Tcrra-cottu for Steel Skeleton Buildings. \Y. L. B. Jenny, architect, in the Brickbnildcr says: " As terra-cotta is the best material adapted for the street fronts of the steel skeleton, lapping" around the horizontal flanges of the girders, to which it is easily secured, and also flreproofmg the steel, the terra-cotta cornice is now in general use." The essentials are: " That the terra-cotta shall be very securely and substantially supported and anchored. To this end the steel and terra-cotta must be designed together. All supports and all anchors must be shown in the design, that the holes in the terra-cotta and in the steel may be made in advance, and the anchors provided. Usually there is a portable forge at the building for heating rivets, where the lengths and shapes of the anchors may be adjusted to tit cor- rectly as the terra-cotta is set. . . . " Strong Portland-cement mortar only should be used. the outer one or two inches the color of the terra-cotta. Unless Portland cement is used, the mortar joints will be af- fected by the frost, and ere long fall out, and water will enter. freeze and displace, or break the terra-cotta. All terra-cotta should be reasonably straight and hard-burned. It is desir- able whenever practicable to consult with the terra-cotta company before the details are finally settled, as they must 326 THE PLANNING AND CONSTRUCTION OF furnish and set the material, and sometimes very valuable suggestions can be obtained from them, contributing to the stability and economy. . . . " An old French professor in the Ecole Centrale at Paris \vas fond of telling his students, ' Xever lose the opportunity to consult with those who know more than you on any sub- ject, and remember that an intelligent foreman often pos- sesses practical knowledge on some minor points not found in the books that may be of great benefit to the professional architect and engineer.' ' This is quite likely to be true in terra-cotta cornices. The terra-cotta must be moulded, baked, and set; and if the facility for doing these three things is constantly kept in view in designing the cornice, the most substantial and the most economical cornice will be obtained. It is often easy to add to the stability and to diminish the cost by chances that do not injure the architectural effect. The terra-cotta used in the Central Bank Building was of a color to match the brick, and used (as shown in a previous chapter) for the main cornice, sills, belt-courses, lintels, mul- lions. caps, and panels. The material was delivered at the building when needed, marked and set complete as the build- ing progressed. For a more exhaustive treatment of the following materials and masonry we refer the reader to Mr. Kidder's " Building Construction." Part I., in which he treats of masonry, stonework, plastering, etc. IJrick and Stone ]\'ork. Of brickwork little if anything need be said. For high buildings the lighter-colored bricks seem to be preferred. ( )f the stonework we mention first the granite base- stones resting upon the concrete foundation-beds. These are made of a size in proportion to the load, the practical requirements being that the blocks shall be Fa;. 140. ELEVATOR CAR. LORD'S COTKT BUILDING. 327 HIGH OFFICE-BUILDINGS. 329 cut to a given size and even thickness, top and bottom bed to have a hammered surface, sides rough-pointed, and each stone to have a hole for the insertion of a lewis. These stones should not be less than 18 inches thick, and be well bedded in Portland cement. Milestone. All walls above roof, if not capped with terra- cotta, should have bluestone. For all window-sills and lin- tels on party-walls and courts it is practicable and economi- cal to use bluestone. All beams and girders resting upon walls should also have bluestone templets, the size and thick- ness depending upon the weight to be carried. Specification Requirements for the Front Cininitc-^'ork in the Central Bank Building. The material will be of light granite. \York on all surfaces with a ten-hammer busher (sample of stone and axing to be approved.) Granite-work is colored on elevations and sections. The full width of building on Broadway front and full depth of building on Pearl Street, all the parts shown above sidewalk line to first-story sill-course inclusive, architraves to two entrance-doors on Broadway; also all work on Pearl Street front shown below sidewalk line to basement-area level. To include sills, lintels, and mullions to windows, steps and sills to main-entrance doorway. All face-stone and all projecting quoins and jambs will be of ashlar, to be of thickness figured; all granite to rest on walls as shown on : , ! -inch detail drawing's. Joints will be of uniform size, not to exceed 3-10 in - ()n f< l( ^ and j in. on back of stone. All granite to have full and true beds, and bind into brick and stone work. Anv stone which mav crack or break lie- fore the final completion of the building, or which may show any defects, to be removed and replaced bv a new and per- fect stone, without anv extra cost to the owner. 33O THE PLANNING AND CONSTRUCTION OF All granite-work to be thoroughly anchored and clamped; clamps and anchors to be furnished by other par- ties, this contractor setting same. The sizes of stone, joints, cuts, etc., are fully shown upon the 4-inch scale and full-size drawings, and must be strictly followed. This contractor must provide all men necessary at the building to do all required fitting of his stonework to skele- ton frame. Also all cutting and jobbing for other me- chanics. All wood centres and uprights for openings will be fur- nished by other parties as required. This contractor will carefully cover and protect with white-pine wood all stone sills, corners, carvings, and all other exposed parts of his work from the time of erection to the completion of the building. All moulded work to be run sharp and true and axed as lor face- work. Carving will be done by skilled carvers at building from models furnished by this contractor and approved by archi- tect. All sills to have wash, drips, and lugs cut. All cor- nices and sill-courses to have wash and drips cut on same. This contractor will be required to furnish his own putty- mortar for pointing, and Lafarge cement for setting stone- work and facing up the same. ( )n the completion of the building, and immediately after the upper part of the building is cleaned down, this contrac- tor will remove all boxing and protections to his work, and clean down the granite-work, using water and steel-wire brushes, pointing the entire work, removing and replacing any broken or defective work, leaving the whole perfect on completion. flustering. We have eliminated liiuc plaster from our I-'lii. 141. Dl-.IAli. OK El.KVATuK [''ROMS, HIGH OFFICE-BUILDINGS. 333 large buildings, and instead are using improved wall plasters, such as " Acme," " Adamant," and " King's Windsor Ce- ment dry mortar." The Central Bank Building was plastered with " King's Windsor Cement." This is a dry mortar, in which certain chemicals are mixed with Xova Scotia gypsum of a superior quality to form the cement, and the mortar is made by mix- ing with the cement washed and kiln-dried pit sand and as- bestos fibre, all the materials being weighed and uniformly mixed by special machinery. The Adamant is a chemical preparation. The Acme cement plaster is produced by calcining the natural earth at a high degree of heat (about (>oo Fahr. ), which rids the material of not only the free moisture, but also the combined moisture. Their principal advantages lie in their uniformity in strength and quality, greater hardness and tenacity, freedom from pitting, less weight, saving in time required for making and drying the plaster, minimum danger from frost, and greater resistance to fire and water. For the brick walls in the Central Bank Building two coats were applied; three coats were given to ceilings, tire- proof partitions, wire lath, etc. This cement was used ex- tensively throughout the building from cellar to roof. The finishing coat and all plaster cornices were of hard-finished plaster of Paris, cornices being carried through all halls, cor- ridors, and rooms, and in many cases heavily moulded. Interior Marble }]'ork. As used in these buildings ilii- includes all marble for plumbing in toilet-rooms and for wash-basins in offices: and marble wainscoting and mosaic floors in all halls, corridors, and toilet-rooms. For the plumbing work the basin slabs in rooms are made of i j-inch pieces, with hole for I I to 14 inch to i^ to i~ inch 1>a ft. 9 in. to 7 ft. high, of i]-inch marble, capped with 1 1-inch moulded pieces. They are placed about 2 ft. 9 in. to 3 feet centres, and extend from the wall to jamb of small flap-door from 4 ft. 6 in. to 5 ft. At the back of each of these small rooms 6 inches should be allowed for the marble lining and air-pipes. Wainscoting in toilet -rooms should extend on all sides and l)e about 5 feet high; for the corridors 4 ft. 6 inches high will be sufficient, the cap member acting as a sill for the win- dows of the partitions. The tanks for each individual closet have marble cover- ings 4 inch thick. In connection with the corridors (which are generally covered with marble mosaic) there should be marble saddles to all doors opening into these rooms, and base-blocks for the door trim. The execution of the entire work should be as follows : All wainscoting, plumbing, marble partitions, base- blocks, and saddles to have exposed surfaces, edges, and mouldings rubbed and highly polished; all set in plaster of Paris and cement, with close joints, and free from stains of anv kind. The plumber and the marble contractor must work to- gether in the setting of plumbing marble and fixtures. All work to be cleaned down and any broken or damaged work removed and made good, and all parts of the work left whole and perfect on completion. Interior Trim and ]]*oodi^ork. All the stock for the in- terior trim and woodwork of the Central Hank Fuilding is i.VNK <>]' LoMMKKCK BfII.DI.NG. HIGH OFFICE-BUILDINGS. 337 of the best quality quartered oak. and includes the following: Hack lining throughout all window jambs not plastered; architrave for all windows and doors; caps on top of wooden cornices on all communicating doors between offices; base throughout all offices /',' > ^ in., with necking 4.] in. and base-mould I : J in. 'Idle interior work includes all sash, doors, chair-rail, and picture-mouldings. All communicat- ing doors have saddles 6 x ; in., moulded. The stair-rail, water-closet doors, and freight-elevator doors are also in- cluded. The work before being put in place was all prepared at the mill, framed together where practical, stained, tilled, and given one coat of white shellac before delivery. The back was also painted one coat of metallic paint. All woodwork in cellar is of white pine, painted. 1' A I. XT ING. Painting Iron and Steel. On exposure to the atmosphere all metals soon lose their lustre; they oxidize by absorbing oxygen from the air. Iron and steel become coated with a layer of hydrated sesquioxide of iron or rust. The change takes place rapidly, every drop of rain causing a rust stain, and hence only when free from rust can metal be successfully painted. \Yhen the oxidizing process has once commenced. its progress may for a time be interrupted by painting, but it progresses slowly even under the paint, the latter finally peeling off, together with a layer of rust. The principal point in painting steel or iron is the prim- ing coat, and for this to be effected the paint must be capable of drying- quickly and thoroughly, be thinly fluid and lightly applied, so that all inequalities of the surface to be painted may be covered. For ordinary purposes we believe there is no better paint to apply than red lend mixed with linseed-oil. 338 THE P LA XX IXC, AXD CONSTRUCTION OF one coat to be put on at the works and another when the iron is erected, riveted, and bolted up complete at the build- ing. Red lead or litharge is protoxide of lead produced by ex- posing' melted lead to a current of air. It fuses readily, and on cooling forms a mass consisting of glistering, semi- transparent, yellow or reddish-yellow scales. It generally contains more or less red lead, whence the variation in color. Red lead has density, weight, body. To get the heavv pigment thoroughly incorporated with the lighter raw lin- seed-oil, for the second coat, put in considerable red lead and comparatively little oil. By so doing the particles of red lead will not settle out of the vehicle either in the pot or on the surface, and greater covering will be had than in a thin mixture. For the priming coat, and to sustain the heavy particles of red lead, the introduction of a small quantity of japan made with raw linseed-oil, or the substitution of boiled oil for the raw oil, is desirable to prevent running. From prac- tical test it seems that to each gallon of linseed-oil 20 to 30 Ibs. of pure red lead should be used. There seems to be no par- ticular formula for mixing. This is generally governed by the temperature, moisture, mode of mixing, and skill of the painter. The use of lampblack introduces a new element in the color, giving it a chocolate shade: and some of the railroads in their specifications state that the " paint used should be of the best grade of pure red lead and linseed-oil. Last coat red lead, linseed-oil, and lampblack; one ounce of lampblack to the pound of red lead, mixed fresh every day." Lampblack retards the natural drying properties of red lead, and a small quantity of japan is recommended as a dryer and as a binder for materials of such diverse specific gravity. H1C.H OFFICE~BL'ILDL\'GS. 339 At the present day there is an unlimited number of manu- factured or patent paints put upon the market for painting- iron. \Ve are able to give the analyses of a few, furnished by a competent person, with the percentages of the various in- gredients. An Asfhaltum faint contained Volatile thinner (turpentine) 4-5^ Saponifiable oil (probably linseed) Pigment . The pigment contained ( )xide of iron 05. i 5 Sulphate of lime 34-^5 Sample contained no asphalt. A Carbon l\ii^t contained White lead i />3 Sulphate of lime io.;i Carbonate of lime '4-5- Insoluble matter consisting largelv <">f oxide of iron 7,v4 An .Inti-Rusl I\tint contained Volatile thinner (turpentine) 33-77 Saponifiable oil (probably linseed, con- taining lead and mangane-e soaps).'. . . 37-73 Pigment jS.;o 100.00 34O THE PLANNING AND CONSTRUCTION OF The pigment contained: Lead compounds 4.92 per cent, sulphate of lime 4.50, Venetian red 90.48=100. The Venetian red contained oxide of iron 40.82 per cent, silica 44.45, and water 5.21. These oil-paints, as will be seen, consist of some pow- dered pigment, are fairly durable, and some of them very lasting on wood; but on iron they have not proved to be so. and experience has shown that the metallic oxide acts as a carrier of oxygen to the underlying iron, causing it to rust instead of protecting it. In many buildings where the frame is of steel and iron, asphalt put on hot is frequently used; but from o.ur little experience in that line we believe in the course of time it be- comes hard and useless, and in many cases the asphalt is nothing but coal-tar. Painting of the Interior IVork. The following painting specifications for the Central Bank Building cover all the re- quirements for the interior of an office-building. All materials to be the best of their respective kinds, and at all times subject to inspection for approval or rejec- tion. The workmanship to be of the best and most substantial quality of each of its respective kinds, and will be held under this contract to include the service of all materia.1, tools, labor, scaffolding, etc., and everything requisite to complete entirely the building; also all and adequate protectio.il to life and limb. All interior doors and windows on all floors will have moulded trim and caps where shown. jambs to all doors and interior windows. Windows in outside walls throughout will have a moulded trim, apron, and stool (but no back-lining) except where shown on plans. HIGH OFFICE-BUILDINGS. 34! Base throughout offices 10] in. high with a j;'-mch base- mould. Base in all corridors and lavatories will he of marble. The cellar woodwork, also all window-frames and sash in outside walls throughout building on all floors, will be of white pine (except sash on first story, Broadway and Pearl Street fronts). First-story hall, corridor, vestibule, front doors and sash, also banking-room will be of mahogany. Trim in banking-room, hall, and corridor on first floor will be of marble. The remaining portion of woodwork throughout build- ing, except where otherwise mentioned, will be of quartered i >ak. The exterior parts of white-pine woodwork on all win- daw-frames and sashes throughout the building on street fronts, from cellar to fifteenth story inclusive, also on party- walls and two light-courts, to be painted three (3) coats of color as will be selected by owner or his representative. The pulley-stiles of all window-frames to be given one good coat of raw linsce.d-oil. The galvanixcd-iron work, such as louvres, the top and under side of skylights over stairs and elevators, also ven- tila.tors and vertical covering of bulkheads over stairs, ele- vators, and tank-house, all to be given two (_>) coats of color as directed. ILvtci'ior Ironwork. All the iron beams of the vault and sidewalk construction exposed to view, including the under side of patent lights, coal-covers, tank, door to elevator, tank-house, and stairs on root; also area stairs, area railing, fascias. sills and jambs to basement windows and door: also shutters to eleven windows on sixth floor on rartv-wall lines. 34 2 THE PLA AWY<\ ~G AXD COXSTK L'CTIOX OF and beam bracing across light-courts on eleventh, thirteenth, and fifteenth floor-levels ; also cast-iron work in connec- tion with window-jambs, mullions, fascias, and sills on first story in the two light-courts. Above list of iron and metal work to be painted two (2) coats of color as will be directed. Interior Ironwork. The main stairs from basement to roof, and bank stairs from basement to mezzanine floor; also elevator-enclosure for five passenger-elevators from first rloor to fifteenth story inclusive, wdl be in electro-bronze tinder another contract, with these exceptions : That back of mullions and transoms and fascias on ele- vator sides of the five passenger-elevators will be painted: also the store stairs from cellar to first floor and main stairs from cellar to basement floor: also ironwork on both sides of floor-lights in basement and first floor. All interior ironwork in five passenger-elevators and one freight-elevator, such as beams, gtiides, i'ascias, back of mul- lions and transoms, saddles, overhead way and beams, grat- ing, counterweight, guides, elevator-pits, and iambs, etc., to freight-elevator: also cast-plate to shipping entrance; door to boiler-flue and coal-vault: also all cylinders and all pipes connecting with elevator machinery in shafts. The iron jambs of freight-elevator in corridor side to be of grained oak. Above list of interior ironwork to be painted on all ex- posed surfaces with two ( 2} coats of color as will be directed. ll'oodeu (iitidcs. The wooden guides to elevators to be given two coats of paint. Xote: This contract to cover the painting of all exposed plumbing pipes, leader-pipe-, and tire-lines; all to have two ( j) coats < f rHors <'^ \vill be directed. Interior / ; /'v ll'oodisnrk. All interior exposed parts of window-frames aiid white-pine sashes in outside walls on ///(/// OFFICE-BUILDINGS. 343 each floor (except pulley-stiles) to be Drained to correspond with finish of rooms and two (2) coats of Crockett's or other approved varnish applied, the last coat to be rubbed as speci- fied herein. In cellar the pine woodwork to be painted three (3) coats of color as will be directed. Paint. All paint used in this work to be of pure Atlantic white lead, mixed with pure linseed-oil in such colors as will be directed. I lardi^'ood. All oak and mahogany used in this building will arrive at site tilled, stained, and have one coat of white shellac and the back of all woodwork painted one coat. This contract is to cover the proper protections until hard and drv. also clean and sandpaper where required and when so directed before varnishing. The painter to touch up with staining coat all surface which has been planed ott at building; also putty-stop all nail-holes and defects. All hardwood work herein specified to be used in building to be given three (3) coats of Crock- ett's varnish or equally as good, the last coat to be rubbed down with pumice-stone and crude oil to a dead finish. Stair-rail. All stairs will have a moulded hand-rail. Toilet-room doors, i - ( X in number, located on the different floors. Chair-rail, picture-mould around walls of all offices. Hardwood saddles to all doors except corridors. The above to receive same finish as tor hardwood herein specified. Safct\ ]\'indo-^' Appliances. We are informed by the I'olice Hoard that in \ew York Citv alone the number ot deaths resulting" from accidents incidental to window-clean- ing during the period 1885 to i8 ( ;j> averaged fifty per year. On account of the great height ot office-buildings, the opera- tion of cleanmir becomes at times verv ha/ardous. To rein- 344 THE PLANNING AND CONSTRUCTION OF ccly this several contrivances are now in use; among them is one which should be generally adopted, by which the sash is swung into the room. Revolving Entrance-doors, The revolving entrance-doors which are supplied to some tall buildings must now be con- sidered a factor in their equipment. Of the many merits claimed, one in particular is the complete exclusion of all wind, rain, snow, and dust during storms while persons are passing in and out; also the prevention of cold draughts in winter. In warm weather the doors are folded and pushed to one side. Roofing. Under this heading, if not already under sheet- metal work, the roofer will supply the Hashing, which is of copper and is set around all walls, bulkheads, etc. The under-flashing should be I 5 inches wide, that is, 6 inches on roof and 9 inches turned up on walls, and secured to the walls with drive-hooks. Cap-flashing' should be 10 inches wide, turned in wall 3 inches, and / inches down the wall over the under-flashing. Where copper flashing comes in contact with any galvan- ized-iron work it should be connected in such a manner as to prevent any galvanic action taking place. The roofing con- tractor will also furnish copper pans about 16 inches square at the head of all leaders. After the finished concrete is set on roof, a layer of tar should be applied, then three-ply tarred felt-paper, laid with two thirds lap and one third exposed, each layer cemented to the one underneath; then cover with another coat of tar. When all other mechanics are finished on the roof, apply a final covering ( ^f three layers of similar felt with large lap. properly cemented and connected with flashing. Cover the above felting with f> x 9 x i in. red vitrified tile, laid to grades of roof, and bedded in Portland cement and grouted with HIGH OFFICE-BUILDINGS. 345 the cement in a liquid form. Tiles to break joints laid in a line and straight, the joints not to exceed { inch. The tank-house to he prepared as the main roof and cov- ered with :',' inch of asphalt. Hardware. The introduction of locks with tlat sheet- metal keys has revolutionized the lock industry of the L'nited States to such an extent that every lock-maker is now producing flat-keyed locks, and it is an exception to see a high office-building having anything but the latest im- proved hardware throughout. The handbooks of the vari- ous hardware companies show, in the most effective modern methods of illustration, numbers of artistic designs and prac- tical details of their wares. Many of the patterns shown in their books are designed by the artists of the companies, and are offered to the public in an open market. IN coxci.rsrox we wish to state that a few items have been omitted as being immaterial to our subject, and with respect to these we refer the reader to books on Building: Construction. . Is lite class of work put /;/ ///;'// office-building's is of the first order, requiring specially skilled workmen, we hare inserted, for tlie be tie fit of those /or whom I his book is infolded, and for all concerned, cards of a few of the business firms w-Jio hare been identified with the con - st ruction of the various buildings illustrated. ENGINES, DYNAMOS, AND ELECTRIC WIRING, The Brooklyn Electric Equipment ELECTRIC AI, CONTRACTORS. 164-166 MONTAGUE STREET. CENTRAL NATIONAL BANK BUILDING. - JOHN T. WILLIAMS, Architect. BROOKLYN INSTITUTE OF ARTS, McKiM, MEAD & WHITE, Architects. LORD S COURT BUILDING, - JNO. T. WILLIAMS. Architect. HUDSON BUILDING, - - - CLINTON & RUSSELL. Architects. NEW YORK WOOL WARIHOUSE, - - W. B. TUBBY, Architect. T. P. GALLIGAN & SON, House Movers and Contractors, OFF in: IVINS SYNDICATE BUILDING. _~ o _ . ASTORIA HOTEL. 528 Bust \ 7th Street, MANHATTAN HOTEL. EMPIRE BUILDING. NEW YORK NEW YORK LIFE INSURANCE CO. CENTRAL BANK BUILDING. Telephone Call, im-iSth St. Etc . etc. Night 1828-381)1 St. JOHN MCMILLAN, PLUMBER AND GAS-FITTER, .u>s I.KXIXC ; r< >x AVKXUK, NEW YORK. EST1MA y'A'.V REFhRKNCHS: Central Bank Building. Lord's Court Building. EXAMINATIONS. Silk Exchange Building. HECLA IRON-WORKS (Formerly POULSON & EGER), Iron Stairs, Elevator Enclosures and Cars, CAST AND GALl/ANO BRONZE, BOWER-BARFF AND ELECTROPLATE FINISHES IRON STAIRWAY IN THE NEW YORK CLEARING-HOUSE. OFFICE, WORKS, AND EXHIBIT ROOMS: . 10th, llth, and 12th Sts., bet. Wythe Ave. and Berry St. BROOKLYN, NEW YORK. JOHN BOYLAND, PLASTERER, 487 BROADWAY, corner of BROOME STREET, NEW YORK. TELEPHONE CONNECTION. References : CENTRAL BANK BUILDING, ARISTON BUILDING, Etc., etc. Applicable io old or new, Power Pldnts For ddvantd$es send for pamp/i/ets. WARREN WEBSTER &co. CHICAGO. CAMDEN.N.J. ' " ^V This system is in use in the CENTRAL BANK BUILD- ING (see pages 260 to 264 ot this book) and many other tall buildings in the principal cities of the United States. A list of references furnished on ap- plication. ELECTRIC ELEVATOR SIGNALS, New York Telephone Building. Standard Oil Building, Commercial Cable Building, Hotel Royalton, ELEVATOR SUPPLY AND REPAIR COMPANY. 136 Liberty Street. .'I'f lincrifition rt CI-MC;AOO : 36 West Monroe Street. -j? \ cf thh Awi. MULTIPLEX STEEL-PLATE FIRE-PROOF CONSTRUCTION tt H M H M MH H I For Floors, Ceilings, Roofs, and Partitions, Striiit'st Jiu1 nio^t economical srstt'ni in /<><. S,\' /Vfiy i =,* of //'/* book. S( )I K M \NTKAi: I I'KKKS : THE BERGER MANUFACTURING CO.. Caitun. Ohio. NEW YORK OFFICE' 210 BAST 23d STREET. Telephone, No. 2632 i8tn Street. CHICAGO A&tr.CV. ILLINOIS ROOFING AND SUPPLY CO., 2O3 1..AKK S I KKK r. Telephone, Main 3880. "A System of Fireproofing that is FIRE-PROOF." 1 he recent severe fire and water tests made by the New York Building and Fire Departments have proved conclusively that the Roebling Fire=Proof Floors are absolutely fire=piroof. The superiority of concrete over hollow tile as a fire- and water-resisting material has been established by practical tests, and fully confirmed by a comparative test of the two materials made by the Building Department of New York City on November 19 1897. The Roebling Standard Wire Lathing with the solid woven-in rib is used exclusively in the Roebling System of Fireproofing. Estimates for Floors. Ceilings, Partitions, etc., and for furring and applying wire lathing- to Columns and Girders, and for Cornice Cove' and Ornamental Plaster work, furnished promptly on application. Contracts made for the erection of all work of this character. Send for illustrated circu lar on tire-proof construction, tire and water tests, etc. (See pages 138-142 for detailed description of the Roebling System, i JOHN A. ROEBLING S SONS CO., 117-119 Liberty St.. New York City. TDPMTnv V I 171-173 Lake St.. Chicago, III. IKtlMtNN, >. J. 25-27 Fremont St.. San Francisco. Cal. The Johnson System of Temperature Regulation. Extensively used in the United States in public- and office buildings, libraries, colleges, schools, and residences, for regulating automatically the temperature of rooms warmed by all systems of heating. Over 30,000 Thermostats have been installed, and fully 60,000 diaphragm steam- valves. Correspondence solicited and descriptive cata- logue furnished upon application. (See pages 273-277 of this book.) JOHNSON TEMPERATURE REGULATING CO., 240 KOLJKTM . \VKXl IK, NEW YORK. PENCOYD IRON WORKS. PKRCIVAI. RDHERTS, /Vv.wV/Vw/. I'ERIMVAI. ROHERTS, Jr., /"/-/'>-<.> /',/,/. P. W. RoHERTS, Treasurer. FREDERICK SNARE, Secretary. A. & P. ROBERTS COMPANY. M ANU FACT TREKS OF Open=Hearth Steel Bars and Structural Shapes, Car and Engine Axles. DKSKiNKRS AM) HflLDF.RS OF BRIDGES, VIADUCTS, TRAIN=SHEDS, ELEVATED RAILROADS, ALL STEEL STRUCTURES. 01 I If /..S ; 261 South Fourth Street, - Philadelphia, Pa. American Surety Building, New York. 27 State Street, - - - Boston, Mass. TERRY & TENCH CONSTRUCTION CO., 1945 SEVENTH AVENUE, NEW YORK, Contractors for and Kreetors of STRUCTURAL STEEL. THE FOLLOWING STRUC'l I'RES HAVE BEEN ERECTED BY US: NY C. & H. R. R. Four-track Drawbridge crossing Harlem River; Central Bank Building ; MiUs House No. i ; Hudson Building, 32 and 34 Broadway ; Anderson Building, 12, 14, and 16 John Street; Grand Central Depot ; and many others. LONG DISTANCE TELEPHONE. SHOP, 117 HARLEM. OFFICE AND RESIDENCE. 113 HARLEM TELEPHONE, 840 SPRING. 13LAKE & WILLIAMS, STEAM AND ELECTRICAL ENGINEERS AND CONTRACTORS, 362 AND 364 WEST BROADWAY, NEW YORK. ELECTKIC, I'OH'KIt, HK.ITIXG, A \ /> l'I.\TI LITI \re placed correctly and quickly. The following illustration is our Directory in the Central Hank Building. It is enclosed by a simple and effective marble frame, furnished by owners. Manhattan Life Ins. Building. New York. Fisher Building, Chicago. Bowling Green " " " Reliance " St. Paul Masonic Temple, Lord's Court Old Colony Building. Queen's Insurance " Stock Exchange And Fifty-four other Buildings in And Fifty-eight other Bui/dings in New York. Chicago. Also, to Thirty-five Buildings in ot^or Cities. rJ Catalogue and full information mailed mi rf<|ne*t. TABLET AND TICKET CO., 381 BROADWAY, NEW YORK. 87 89 FRANKLIN ST., CHICAGO, ILL. The name of is a guarantee Light and Power for OKics-Buildirgs Westingfnouse Compactness, perfect ventilation, lowest tem- pi- , perature, highest efficiency, type and Kodak Generators Save Space and Money. Fewest parts, least wear, least attention. Light and power from one circuit. Westinghouse Electric Apparatus the standard everywhere. Electric Elevators, Cranes, Hoists. Westinghouse Electric and Mfg. Co. Pittsburgh, New York, and all principal cities. JAMES BMGGS & COMPANY, 9 DEY STREET, NEW YORK, MAM'KAf I L'UKKs i >V I UK McClave Shaking, Dumping, and Cut-off Grate-Bar, FOR BURNING CHEAP FUEL 5U CCESSFL'LLY. By its use you can clean your fires from the bottom and without opening the fire-doors MCCLAVE GRATE COMPLETE IN TWO SECTIONS. Sprague Electric Company. GENERAL OFFICE: WORKS: 20-22 BROAD STREET, WATSESSING, N. J. Q>mmcrcial Cable Building. Builders of twelve sizes and types of ELECTRIC ELEVATORS, both Drum and Multiple Sheave, Single, Double and Triple Deck. These machines are manufactured to meet all commercial elevator requirements, from the lowest to the highest Among the equipments m buildings from 5 Also representative buildings throughout the to 21 stories in height and *mh from 2 to 22 United States and Canada , viz . . machines each, are the following in New York Boon/ of Trade Building, Chicago. Postal Telegraph Building, Guarantee Buffalo. Commercial Cable Building, Canada Life Insurance Bldg., Montreal. Astoria Hotel, City Hall & Court House. Salt Lake City. Astor Court Building, City Hall & Court House. Minneapolis. Manhattan Hotel, State Mutual Life Assur. Bldg. .Worcester. New York Telephone Company's Building, Union Trust Building, Detroit. Queen Insurance Company' ' s Building, Majestic Lord's Court Building, Currier Bank " - Los Angeles, Syndicate Building, Wilcox Wadsworth Building, Homer Laugh/in Building, Exchange Court Building, Parrott " San Francisco. R. G Dun Building. Examiner Young Men ' s Christian Association Bldg. , Academy of Music, Park Row Syndicate Building, Safe Deposit Gerken Building, Hotel Walton, - Philadefyhia. Siegel Cooper Department Store, Senate Wing U. S Capitol, Washington. W. W. Beebe s Warehouses, Public Printer s Building, Cushman Building, State House, Albany. Gill Building. Boston Globe, Boston. During the past year many automatically controlled Electric House Elevators have been installed, among them being one in the Executive Mansion, Washington. D C.. also ; n the residences of J. Pierpont Morgan. - New York City. Geo. S. Bowdin - - New York City. William Waldorf Astor, " " " Mrs Almeric Paget. Dr. Francis Kinmcutt. ' Dr. James. - George R. Reed. W. E. Bliss. William A. Reed, Joseph Eastman, R. Fulton Cutting, - A. M. Byers. - Pittsburgh. Pa. fiobt. Olyphant. Wm. Flinn, Western National Bank Building, New York City Harmome Club KING'S WINDSOR ASBESTOS CEMENT AND CEMENT DRY MORTAR, BOTH FOR PLASTERING WALLS AND CEILINGS. The former to be used with sand. The latter, being already mixed with sand, requires but the addition of water. Our Cement Dry Mortar cont'dins only Washed Silicious Sand. J. B. KING & CO., Sole Patentees and Manufacturers, 21-24 STATE STREET, NEW YORK, N. Y. The practical Testimony of the great merits and appreciation of our WINDSOR CKMENT is that leading architects throughout the country have called for it on their best and most costly structures, while architects generally have specified it for all kinds and grades of buildings, expensive and inexpensive, as extra cost does not debar its use on even the humblest cottage. Millions of barrels of it have been used within the last three years. We improve this opportunity to tender our thanks to all patrons, and to invite ail AHCIUTKCTS everywhere m send fur our complete treatise on the subject of "Needed Im- provement in Plaster :or Walls and Ceilings," and also our " Practical Evidence of Superiority," an octavo pamphlet of 64 pages, containing about 4000 of the buildings on which our material has been used the buildings being classified and indexed as follows : Office. Insurance, and Bank Buildings. Federal. State, County, and Town Buildings. Hospitals, Asylums. Sanitariums, etc. Theatres, Opera Houses, Halls, etc. Colleges, Seminaries, Libraries, I.aborato- Hotels. res, etc. Apartment Hotels, Apartment Houses, ai d Public School Buildings. Flats. Churches and Rectories. Business Buildings, Store.-.. I locks, etc. Young Men's and Young Women's Christian Railroad Iiepots and Stations. Association and Women's Christian Tem- Mills. Factories. Breweries, etc. perance Union Buildings. Miscellaneous Buildings. Masonic Temples, etc. Residences. Plar.er Beard: aad TV K A /^"^ T T* T~7 Elevate: and lust-waiter Bli:. 1V1/\^"1 I tL. Chart: a Gpe:ia:t7. LAID LAW & MACDONALD, Fire-proofing, 2- and 3-inch Fire-proof Partitions, 81 PINE ST. and 128 WATER ST., NEW YORK. BARNARD COLLEGE. New York . . LAMB A; RICH. Architects. WOOUBRIDGE BUILDING ..... CLINTON A: RUSSELL. FAHY'S .... And refer to man Large Elevator Plants NOW UNDER CONSTRUCTION KY OTIS BROTHERS & Co. 38 Park Row, New York ARCHITKCTS ARCHITECTS Tower Building 4 James B. Baker University Club Henry Corn - 2 Robert Maynicke House - - 4 McKim, Mead & White Hospital for Rup- Empire Building - 10 Kimball & Thompson tured & Crippled 2 Charles C. Haight Isaac V. Brokaw Singer Building 3 Krnest KlagK (Sherry's) - - 14 McKim. Mead \ White F. ri. Mela - 2 Cleverdon & Putzel N. Y Athletic Club 4 \V. A. Cable Jos. H. Bauland Standard Oil Co. - 10 Kimball & Thompson Co. - - 3 Alfred K Partitt Appraisers' Stores 14 Supervising Architect Hudson Building 4 Clinton & Russell Tri-asurv l)r|>!. Washington Life Joseph Home & Co. 7 Peabody : Stearns Building- - 9 C. I.. W. Ki.ilit/. Mutual Building Co. 2 Bradford I.. Giibi-rt The Otis Elevator the Standard for 40 years S-e iiesc' ptmn of Central Fank Plant, pages ^45-249 o' ( s r-rok SKELETON CONSTRUCTION AS APPLIED IN BUILDINGS. By \VM. H. OIRKMIRE. Fully Illustrated with Enyravinys front Practical Ejc of Hiyh litiiMinfjfi. Svo, C otli. FVic^, S3. CO. This work includes the description and practical working- details of Cast Iron, Wrought Iron, and Steel Columns in the construction of the skeleton frame, and their connections with the Floor and Curtain Wall Girders; Stability of the Structure; Wind Bracing, i.e., Knee and Lateral Bracing 1 ; Construction of Joints; Experiments on the Strength of Cast Iron, Wrought Iron, and Steel Columns, such as Z Bar Columns, Phoenix Columns, Plate and Angle Columns, and various commercial rolled shape columns ; Floor Framing in the Skeleton Construction. New York Building Law of 1892 in relation to the Skeleton Frame and Curtain Walls. The same law in relation to the strength of Cast Iron, Wrought. Iron, and Steel Columns. Illustration and Calculation of the Columns, Floor Plans, Tables of Material, Specification, Stairways, Elevators, and Roofs in buildings using Cast Iron, Wrought Iron, and Steel Columns as a skeleton frame, such as "The New Netherlands," a seventeen-story building with nineteen tiers of beams; the Home Life Insurance Building, and others. FOR SALE BY JOHN WILEY & SONS, 53 East Tenth Street, New York Remington & Sherman Co., MANUFACTURERS OF THE BEST SAFES AND VAULTS. 23 FAI*K; FMLACE, XEW PLANS AND ESTIMATES SUBMITTED WITHOUT COST. THE PASSAIC ROLLING MILL CO., N. J., MANUFACTURE ALL STRUCTURAL STEEL SHAPES FOR FIRE-PROOF CONSTRUCTION. New York Office: No. 45 Broadway. correspondence solicited. ESTABLISHED \870. LLE PHONE CALL, SPRING 1051. K. RIJT^LER, CONTRACTOR FOF STEAM AND HOT-WATER HEATING APPARATUS, Complete Boiler and Power Plants, No. 178 CENTRE STREET, NEW YORK. ARCHITECTURAL IRON AND STEEL AND ITS APPLICATION IN THE CONSTRUCTION OF BUILDINGS. WILLIAM H. BIRKMIRE. To the architect or builder who does not care to go into the study of details and construction, and yet desires to avail himself of the practice and experience of others who have made the use of iron and steel their special study, this work is of great value. It treats of Beams and Girders in Floor Construction, Rolled- iron Struts, Wrought and Cast Iron Columns, Fire-proof Columns, Column Connections, Cast-iron Lintels, Roof-trusses, Stairways, Elevator Enclosures, Ornamental Iron, Floor-lights and Skylights, Vault-lights, Doors and Shutters, Window-guards and Grilles, etc., etc., with Specification of Ironwork; and selected papers in rela- tion to ironwork, from a revision of the present law before the legislature affecting public interests in the City of New York, in so far as the same regulates the construction of buildings in said city. With Tables, selected expressly for this work, of the properties of Beams, Channels, Tees and Angles, used as Beams, Struts and Columns, Weights of Iron and Steel Bars, Capacity of Tanks, Areas of Circles, Weights of Circular and Square Cast-iron Columns, Weights of Substances, Tables of Squares, Cubes, etc., Weights of Sheet Copper, Brass and Iron, etc. 8vo, cloth. Price, $3.5O FOR SALK BY JOHN WILEY & SONS, 53 EAST TENTH ST.. NEW YORK. THE REVOLVING DOOR excludes all wind, snow, rain and dust while persons are passing in and out. Adopted and recommended by :' ( " owners of largest buildings in United States and Canada. IV 'rite for Descriptive Cinular. VAN KANNEL REVOLVING DOOR CO., 253 Broadway, New York. Wings revolving. '' always closed.'' Wings folded, and fastened centrally. Wings folded, and moved aside. Wings folded, and locked. AMES IRONWORKS, OiSWKOO, X. V. Branch Offices and Salesrooms : NEW YORK : 38 COHTLA\DT STREET CHIC^G'): 18 SOUTH CA\AL STREET. BOSTON: 50 OLIV-R STREET. PHILADELPHIA: 1026 FILBERT STREET Automatic Engines for High Office-Buildings, See description 011 pages 236-238 of this book. '/ /' Empire Building, New York.Woodbridge Eldg.. New York. Warren Chambers Bldg.. Boston. Potter " Exchange Court. " " City Hall. Philadelphia. Central Bank Bldg." " Hotel Brunswick. Boston. Art Club Building. Lord's Court ' Homoeopathic Hospital. Boston. S. S. White " Board of Trade Building. Chicago. s thrcn^hou: tht llest. COMPOUND RIVETED GIRDERS FOR BUILDINGS. WILLIAM H. BIRKMIRE In order to facilitate the calculation attending the construction of wrought-iron and steel riveted girders, the author has in this book endeavored to supply the link which separates theory from practice. A riveted girder is to be designed; the span, depth, and loads are known ; the strains are calculated by the well-known bending-moment formula;, and largely by the graphic method ; lastly, the details of construction are fully illustrated. The time consumed in wading through a complicated series of equations to reach a few measurements is objectionable at least when such measurements can at once be had by the graphic method; and any one who can draw accurately will be able to calculate and design girders with any number of concentrated loads, arrange plates, place rivets, etc., at once. 8vo. Price, $2.OO. JOHN WILEY & SONS, 53 EAST TENTH ST., NEW YORK. McADAM & CARTWRIGHT ELEVATOR CO., MANUFACTURERS OF Hydraulic, Steam, and Electric Passenger and Freight Elevators HIGH orncn-in Y 258 and 26O Eleventh Ave., NEW YORK CITY. We refer to a few of the buildings in which our elevators are used American Surety Bui ding, Lorsch Bui ding, Grand Central Station, - J. T. Williams Building, Br ad way and White St., Equitable Building, American Lithograph Co Bldg., New York. Ayer Building, - - New York. M tropolitan Street Railroad Company Building, County Court House, Si. Paul, .Mo. The Equitable Buildings of Boston and St. P.. ul. CASSIDY & SON MFG. CO., MAM'KACI TKKKS OK Gas, Electric, and Combination Fixtures, 733 & 135 W. 23d St. and 124. 126 & 128 W. 24th St.. NEW YORK:. Special attention given to High Office-build i MCJ Work. A . S H A H I R O, HOUSE AND FRESCO PAINTER AND HARDWOOD FINISHER, Paper Hanging Kalsomining. Graining, and Marbling. NO. 7O liKOOMK. iS-rKl-.KT, XK \V V()RK. Lord's Court Building. New York. Hartford Building. New York Silk Exchange Arb .eklc American Society of Civil Engineers' Building And several public schools of New York THE PLANNING AND CONSTRUCTION OF AMERICAN THEATRES. WILLIAM H. B1RKMIRE. For general and practical information, upon theatres we refer architects, builders, and others to this book, in which figured plans and views are given of a few of the best known and most popular theatres of this country. The illustrations are of the highest order, embracing complete views of the Castle Square and Gaiety Theatres of Boston; the Fifth Avenue Theatre, the American Theatre, Hammerstein's Olympia, the Abbey Theatre, the Empire, and other theatres of New York; with their main floors, galleries, and complete sections. The book also describes and details the stage and its appurte- nances, and treats of acoustics and sighting. 8vo, cloth. Price, $3.OO, (JR SALE BY JOHN WILEY & SONS, 53 EAST TENTH ST., NEW YORK. Central Fire-proofing Co* HENRY M. KEASBEY, President. Manufacturers of Porous and Dense Ferra-Cotta .... and contractors for the erection of Terra-Cotta Fire-proofing throughout the United States and Canada. This company has five factories and can therefore fill large orders expeditiously. 874 Broadway, cor. isth street. New York. This company supplied the fire-proofing in most of the large buildings illustrated in this book, and refers to the following not included in the book : N, Y..rk AtM-tif Clu)., " * The company did the UCLA-Art Library NA 6230 B5 L 006 222 293 A 001 386 880 University of California SOUTHERN REGIONAL LIBRARY FACILITY 405 Hilgard Avenue, Los Angeles, CA 90024-1388 Return this material to the library from which it was borrowed. : ''