Part 6

In Jersey City, the proportions of the materials are much as in Staten Island. The selection of the dark trap from the Heights behind the city, for the construction of many fronts or entire buildings, is a local feature of interest.

In Hoboken, the same general features prevail as in Jersey City.

The annual reports of the Committee on Fire Patrol of the New York Board of Fire Underwriters, for the years 1881 and 1882, have yielded the following statistics, which, so far as they go, closely approximate my own:

Number of buildings. South of Canal Street 10,553 Between Canal and Fourteenth Streets 26,700 Between Fourteenth and Fifty-ninth Streets 33,815 Between Fifty-ninth Street and Harlem River 18,746 ------ Total 89,814

The materials of construction for this district, which does not include the 23d and 24th Wards, north of the Harlem River, are reported as follows:

Brick, with stone trimmings, and, in part, with stone facings 64,783 Brick and frame 3,616 Frame 21,415

II. THE BUILDING STONES, THEIR VARIETIES, LOCALITIES, AND EDIFICES CONSTRUCTED OF EACH.

An exceedingly rich and varied series is brought to our docks, and the number and variety are constantly increasing. A few of the more important may be here mentioned.

Freestones (Carboniferous sandstone), commonly styled "Nova Scotia stone," or "Dorchester stone," in various shades of buff, olive-yellow, etc., from Hopewell and Mary's Point, Albert, N. B., and from Wood Point, Sackville, Harvey, and Weston, N. B., Kennetcook, N. S., etc. A very large number of private residences in New York and Brooklyn, etc., the fences, bridges, etc., in Central and Prospect Parks, many churches, banks, etc.

Freestone (Mesozoic sandstone), commonly styled "brownstone," from East Longmeadow and Springfield, Mass., but chiefly from Portland, Conn., in dark shades of reddish-brown, inclining to chocolate. This is the most common stone used in the fronts of private residences, many churches, Academy of Design in Brooklyn, etc.

Freestone (Mesozoic sandstone), "brownstone," from Middletown, Conn., Trinity Church, Brooklyn, etc.

Red sandstone (Potsdam sandstone), Potsdam, N. Y. Several residences, buildings of Columbia College, etc.

Freestone (Potsdam sandstone), "brownstone," Oswego, N. Y. Part of Masonic Temple in 23d Street.

Freestone (Mesozoic sandstone), "brownstone," in several shades of light reddish-brown, orange-brown, etc., and generally fine-grained, from Belleville, N. J. Very many of the best residences and churches, _e. g._, cor. 60th and 64th Streets, and Madison Avenue, etc.

Also, varieties of the same "brownstone" from Little Falls, N. J. (Trinity Church, New York), from the base of the Palisades (part of the wall around Central Park), etc.

Freestone (Lower Carboniferous sandstone), commonly styled "Ohio stone," from Amherst, East Cleveland, Independence, Berea, Portsmouth, Waverly, etc., Ohio, in various shades of buff, white, drab, dove-colored, etc. Many private residences and stores, the Boreel building, Williamsburgh Savings Bank, Rossmore Hotel, etc.

Freestone (Mesozoic sandstone), often styled "Carlisle stone," from the English shipping port, or "Scotch stone," from Corsehill, Ballochmile and Gatelaw Bridge, Scotland; in shades of dark red to bright pink. Fronts of several residences, trimmings of Murray Hill Hotel, the "Berkshire" building, etc.

Also, varieties from Frankfort-on-the-Main, Germany, etc.

Blue sandstone (Devonian sandstone), commonly styled "bluestone," from many quarries in Albany, Greene, Ulster, and Delaware counties, N. Y., and Pike county, Penn. The trimmings of many private residences and business buildings, walls and bridges in the parks, part of Academy of Design in 23d Street, Penitentiary on Blackwell's Island, house at 72d Street and Madison Avenue, etc.

Freestone (Oolite limestone), "Caenstone," from Caen, France. Fronts of several residences in 9th Street, trimmings of Trinity Chapel, the reredos in Trinity Church, New York, etc.

Limestone (Niagara limestone), Lockport, N. Y., Lenox Library, trimmings of Presbyterian Hospital, etc.

Limestone (Lower Carboniferous), styled "Oolitic limestone," from Ellitsville, Ind. Several private residences (_e. g._, cor. 52d Street and Fifth Avenue), trimmings of business buildings, etc.

Also, varieties of limestone from Kingston and Rondout, N. Y., Isle La Motte, Lake Champlain, Mott Haven, and Greenwich, Conn., etc. Part of the anchorages of the Brooklyn Bridge, walls in Central Park, etc.

Granyte, Bay of Fundy, N. S. Columns in Stock Exchange, etc.

Red granyte, Blue Hills, Me. U. S. Barge Office.

Gray granyte, East Blue Hills, Me. Part of towers and approaches of New York and Brooklyn Bridge, etc.

Granyte, Spruce Head, Me. Part of towers of Brooklyn Bridge, bridges of Fourth Avenue Improvement, Jersey City Reservoir, etc.

Gray granyte, Hurricane Island, Me. Part of New York Post Office and of towers and approaches of Brooklyn Bridge, etc.

Granyte, Fox Island, Me. Basement of Stock Exchange, etc.

Granyte, Hallowell, Me. Trimmings in St. Patrick's Cathedral, Jersey City Heights, etc.

Granyte, Round Point, Me. Seventh Regiment Armory, etc.

Granyte, Jonesborough, Me. Welles' building, panels in Williamsburgh Savings Bank, etc.

Granyte, Frankfort, Me. Part of towers and approaches of Brooklyn Bridge, etc.

Granyte, Dix Island, Me. New York Post Office, part of _Staats Zeitung_ building, etc.

Also, varieties from Calais, Red Beach, East Boston, Clark's Island, Mt. Waldo, Mosquito Mountain, Mt. Desert, Ratcliff's Island, etc., Me.

Granyte, Concord, N. H. Booth's Theater, German Savings Bank, etc.

Granyte, Cape Ann, Mass. Dark base-stone and spandrel stones of towers and approaches of Brooklyn Bridge, etc.

Granyte, Quincy, Mass. Astor House, Custom House, etc.

Granyte, Westerly, R. I. Part of Brooklyn anchorage of Brooklyn Bridge.

Granyte, Stony Creek, Conn. Part of New York anchorage of Brooklyn Bridge.

Also, varieties from St. Johnsville, Vt., Millstone Point, Conn., Cornwall, N. Y., Charlottesburgh, N. J., Rubislaw, and Peterhead, Scotland, etc.

Gray gneiss, New York Island, and Westchester county, N. Y. A large number of churches, Bellevue Hospital, the Reservoir at 42d Street, etc., and the foundations of most of the buildings throughout the city.

Gray gneiss, Willett's Point, and Hallett's Point, Kings county, N. Y. Many churches in Brooklyn, the Naval Hospital, etc.

Marble, Manchester, Vt. Drexel & Morgan's building, church cor. 29th Street and Fifth Avenue, etc.

Also, many varieties from Swanton, West Rutland, Burlington, Isle La Motte, etc., Vt. The "Sutherland" building at 63d Street and Madison Avenue, residences at 58th Street and Fifth Avenue, etc.

Marble, Lee, Mass. Turrets of St. Patrick's Cathedral, etc.

Marble, Stockbridge, Mass. Part of old City Hall, New York.

Marble, Hastings, N. Y. The University building, etc.

Marble, Tuckahoe, N. Y. Part of St. Patrick's Cathedral, residence on the cor. of 34th Street and Fifth Avenue, etc.

Marble, Pleasantville, N. Y., styled "Snowflake marble." Greater part of St. Patrick's Cathedral, Union Dime Savings Bank, many residences and stores, etc.

Also, many varieties from Canaan, Conn., Williamsport, Penn., Knoxville, Tenn., Carrara and Sienna, Italy, etc.; used generally, especially for interior decoration, etc.

Trap (Mesozoic diabase), from many quarries along the "Palisades," at Jersey City Heights, Weehawken, etc. Stevens Institute, Hoboken, N. J., Court House on Jersey City Heights, old rubble work buildings at New Utrecht, etc., on the outskirts of Brooklyn, etc.

Trap (Mesozoic diabase), styled "Norwood stone," from Closter, N. J. Grace Episcopal Church, Harlem.

Also, varieties from Graniteville, Staten Island, N. Y., and Weehawken, N. J.

Serpentine, Hoboken, N. J. Many private residences, masonry, etc., in Hoboken. Also, varieties from Chester, Pa.

In addition to the edifices referred to above, many public buildings of importance are constructed of stone, _e. g._: Prisons in the city and on the islands, bridges in the parks and over the Harlem River, in which sandstone, limestone, granyte, and gneiss are used.

The sewers are constructed of gneiss from New York Island and vicinity, as well as of bowlders of trap, granyte, etc., from excavations.

The Croton Aqueduct, the High Bridge, the Reservoirs in the Central and Prospect Parks and at 42d Street, in which gneiss from the vicinity and granyte from New England were used.

The walls, buildings, bridges, and general masonry in the parks are constructed of the following varieties of stone:

Freestone (sandstone), from Albert, Dorchester, and Weston, N. B.

Brownstone, from Belleville and the base of the Palisades, N. J.

Bluestone and "mountain graywacke," from the Hudson River.

Limestone, from Mott Haven and Greenwich, Conn.

Granyte, from Radcliffe's Island, etc., Me.

Gneiss, from New York, Westchester, and Kings counties, N. Y.

Marble, from Westchester county, N. Y.

The fortifications in the harbor and entrance to the sound, constructed of granyte from Dix Island, Spruce Head, etc., Me., gneiss from the vicinity, brownstone from Conn., etc.

The stonework of the New York and Brooklyn Bridge, as I am kindly informed by Mr. F. Collingwood, the engineer in charge of the New York approach, is constructed of the following materials:

Granyte, from Frankfort, Spruce Head, Hurricane Island, East Blue Hill and Mt. Desert, Me., Concord, N. H., Cape Ann, Mass., Westerly, R. I., Stony Creek, Conn., and Charlottesburg, N. J.

Limestone, from Rondout and Kingston, N. Y., also from Isle La Motte and Willsboro Point, Lake Champlain, and vicinity of Catskill, N. Y.

In the anchorages, the corner stones, exterior of the cornice and coping, and the stones resting on anchor plates, consist of granyte from Charlottesburg and Stony Creek, in the New York anchorage, and from Westerly, in the Brooklyn anchorage. The rest of the material is entirely limestone, mainly from Rondout, largely from Lake Champlain. In the towers, limestone was chiefly employed below the water line, and, above, granyte from all the localities named, except Charlottesburg, Westerly, and Stony Creek. In the approaches the materials were arranged in about the same way as in the towers. Additional particulars are given concerning the quantity, prices, tests of strength, and reasons for selection of the varieties of stone.

For roofing, slate is largely employed throughout these cities, being mainly derived from Poultney, Castleton, Fairhaven, etc., Vt., and Slatington, Lynnport, Bethlehem, etc., Penn.

For pavements, the bowlders of trap and granyte from excavations have been widely used in the "cobblestone" pavements. The trap (or diabase) of the Palisades across the Hudson, immediately opposite New York city, and from Graniteville, Staten Island, is used in the "Russ" and Belgian pavement; also, granyte from the Highlands of the Hudson, from Maine, etc, in the "granite block" pavement in both New York and Brooklyn; large quantities of crushed trap from Weehawken and Graniteville, for the macadamized streets and roads in the parks and outskirts; and also wood, concrete, and asphalt in various combinations.

For sidewalks and curbstones, the material generally employed is the flagstone, a thinly bedded blue sandstone or graywacke from the interior of the State, the Catskill Mountains, and from Pennsylvania; also, granyte, chiefly from Maine. In the older streets, a mica slate from Bolton, Conn., and micaceous slaty gneiss from Haddam, Conn., were once largely used, and may still be occasionally observed in scattered slabs.

Additional facts were given concerning the ruling prices for the varieties of stone, tables presenting all the determinations obtainable in reference to the crushing strength of the varieties used in New York, lists of the dealers in building and ornamental stones, etc.

III. DURABILITY OF BUILDING STONES, IN NEW CITY AND VICINITY.

All varieties of soft, porous, and untested stones are being hurried into the masonry of the buildings of New York city and its vicinity. On many of them the ravages of the weather and the need of the repairer are apparent within five years after their erection, and a resistance to much decay for twenty or thirty years is usually considered wonderful and perfectly satisfactory.

Notwithstanding the general injury to the appearance of the rotten stone, and the enormous losses annually involved in the extensive repairs, painting, or demolition, little concern is yet manifested by either architects, builders, or house owners. Hardly any department of technical science is so much neglected as that which embraces the study of the nature of stone, and all the varied resources of lithology in chemical, microscopical, and physical methods of investigation, wonderfully developed within the last quarter century, have never yet been properly applied to the selection and protection of stone, as used for building purposes. Much alarm has been caused abroad in the rapid decay and fast approaching ruin of the most important monuments, cathedrals, and public buildings, but in many instances the means have been found for their artificial protection, _e. g._, the Louvre, and many palaces in and near Paris, France, St. Charles Church in Vienna, Austria, the Houses of Parliament, etc., in London, England, etc.

In New York, the Commissioners of the Croton Aqueduct Department complained, twenty years ago, of the crumbling away of varieties of the gneiss used in embankments; the marbles of Italy, Vermont, and of Westchester county soon become discolored, are now all more or less pitted or softened upon the surface (_e. g._, the U. S. Treasury), and are not likely to last a century in satisfactory condition (_e. g._, the U. S. Hotel); the coarser brown sandstones are exfoliating in the most offensive way throughout all of our older streets and in many of the newer (_e. g._, the old City Hall); the few limestones yet brought into use are beginning to lose their dressed surfaces and to be traversed by cracks (_e. g._, the Lenox Library); and even the granytes, within a half century, show both discoloration, pitting (_e. g._, the Custom House), or exfoliation (_e. g._, the Tombs). To meet and properly cope with this destructive action, requires, first, a clear recognition of the hostile external agencies concerned in the process. These belong to three classes: chemical, physical, and organic.

The chemical agencies discussed were the following: sulphurous and sulphuric acids, discharged in vast quantities into the air of the city, by the combustion of coal and gas, the decomposition of street refuse and sewer gas, etc.; carbonic, nitric, and hydrochloric acids; carbolic, hippuric, and many other organic acids derived from smoke, street dust, sewer vapors, etc.; oxygen and ozone, ammonia, and sea salt.

The mechanical and physical agencies discussed were the following: frost; extreme variations in temperature, amounting in our climate to 120° F. in a year, and even 70° in a single day; wind and rain, most efficient on fronts facing the north, northeast, and east; crystallization by efflorescence; pressure of superincumbent masonry; friction; and fire.

The organic agencies consist of vegetable growths, mostly confervæ, etc., within the city, and lichens and mosses without, and of boring mollusks, sponges, etc.

The internal elements of durability in a stone depend, first, upon the chemical composition of its constituent minerals and of their cement. This involves a consideration of their solubility in atmospheric waters, _e. g._, the calcium-carbonate of a marble or limestone, the ferric oxide of certain sandstones, etc.; their tendency to oxidation, hydration, and decomposition, _e. g._, of the sulphides (especially marcasite) in a roofing slate or marble, the biotite and ferruginous orthoclase in a granyte or sandstone, etc.; the inclosure of fluids and moisture, _e. g._, as "quarry-sap," in chemical combination, as hydrated silicates (chlorite, kaolin, etc.), and iron oxides, and as fluid cavities locked up in quartz, etc.

The durability of a stone depends again upon its physical structure, in regard to which the following points were discussed: the size, form, and position of its constituent minerals; _e. g._, an excess of mica plates in parallel position may serve as an element of weakness; the porosity of the rock permitting the percolation of water through its interstices, especially important in the case of the soft freestones, and leading to varieties of discoloration upon the light-colored stones, which were described in detail; the hardness and toughness, particularly in relation to use for pavements, sidewalks, and stoops; the crystalline structure, which, if well-developed, increases the strength of its resistance; the tension of the grains, which appears to explain especially the disruption of many crystalline marbles; the contiguity of the grains and the proportion of cement in their interstices; and the homogeneity of the rock.

Again, the durability of a rock may depend upon the character of its surface, whether polished, smoothly dressed, or rough hewn, since upon this circumstance may rest the rapidity with which atmospheric waters are shed, or with which the deposition of soot, street dust, etc., may be favored; also upon the inclination and position of the surface, as affecting the retention of rainwater and moisture, exposure to northeast gales and to burning sun, etc.

IV. METHODS OF TRIAL OF BUILDING STONE.

In such methods, two classes may be distinguished, the natural and the artificial.

The former embrace, first, the examination of quarry outcrops, where the exposure of the surface of the rock during ages may give some indication of its power of resistance to decomposition, _e. g._, the dolomitic marbles of New York and Westchester counties, some of which present a surface crumbling into sand; and, secondly, the examination of old masonry. Few old buildings have survived the changes in our restless city, but many observations were presented in regard to the condition of many materials, usually after an exposure of less than half a century.

Another source of information, in this regard, was found in the study of the stones erected in our oldest cemeteries, _e. g._, that of Trinity Church. There could hardly be devised a superior method for thoroughly testing by natural means the durability of the stone than by its erection in this way, with partial insertion in the moist earth, complete exposure to the winds, rain, and sun on every side, its bedding lamination standing on edge, and several of its surfaces smoothed and polished and sharply incised with dates, inscriptions, and carvings, by which to detect and to measure the character and extent of its decay. In Trinity Churchyard, the stones are vertical, and stand facing the east. The most common material is a red sandstone, probably from Little Falls, N. J., whose erection dates back as far as 1681, and which remains, in most cases, in very fair condition. Its dark color, however, has led to a frequent tendency to splitting on the western side of the slabs, _i. e._, that which faces the afternoon sun. Other materials studied consisted of bluestone, probably from the Catskills, black slate, gray slate, green hydromicaceous schist, and white oolitic limestone, all in good condition, and white marble, in a decided state of decay.

The artificial methods of trial of stone, now occasionally in vogue, whenever some extraordinary pressure is brought upon architects to pay a little attention to the durability of the material they propose to employ, are, from their obsolete antiquity, imperfection, or absolute inaccuracy, unworthy of the age and of so honorable a profession. They usually consist of trials of solubility in acids, of absorptive power for water, of resistance to frost, tested by the efflorescence of sodium-sulphate, and of resistance to crushing. The latter may have the remotest relationship to the elements of durability in many rocks, and yet is one on which much reliance of the architectural world is now placed. Sooner or later a wide departure will take place from these incomplete and antique methods, in the light of modern discovery.

Reference was made to certain experiments by Professor J. C. Draper on the brownstone and Nova Scotia stone used in this city, by Dr. Page, on a series of the building stones, and by Professors J. Henry and W. R. Johnson on American marbles, in some cases with conflicting results, which were probably due to the limited number and methods of the experiments.

V. MEANS OF PROTECTION AND PRESERVATION OF STONE.

We have here to consider certain natural principles of construction, and then the methods for the artificial preservation of the stone used in buildings. Under the first head, there are four divisions.

_Selection of Stone._--As it is universally agreed that the utmost importance rests upon the original selection of the building material, it is here that all the resources of lithological science should be called in. Only one investigation, aiming at thorough work, has ever been carried through, that of the Royal Commission appointed for the selection of stone for the Houses of Parliament. But the efforts of these able men were restricted by the little progress made at that time in the general study of rocks, and were afterward completely thwarted by the discharge of the committee and by the delivery of the execution of the work of selection to incompetent hands. There will be hereafter, from investigations made in the light of modern researches, no excuse for such annoying results and enormous expenses as those which attended the endless repairs which have been required, since a period of four or five years after the completion of the great building referred to.

_Seasoning._--The recommendations of Vitruvius 2,000 years ago have been observed at times down to the day of Sir Christopher Wren, who would not accept the stone which he proposed to use in the erection of St. Paul's Cathedral, in London, until it had laid for three years, seasoning upon the seashore. Since then little or no attention appears to have been paid to this important requirement by modern architects, in the heedless haste of the energy of the times. Building stone, even for many notable edifices, is hurried from the quarries into its position in masonry, long before the "quarry-sap" has been permitted, by its evaporation to produce solid cementation in the interstices of the stone.

_Position._--The danger of setting up any laminated material on edge, rather than on its natural bedding-plane, has been widely acknowledged; yet it is of the rarest occurrence, in New York city, to observe any attention paid to this rule, except where, from the small size or square form of the blocks of stone employed, it has been really cheapest and most convenient to pile them up on their flat sides.