FKANCIS C. FRARY HE oldest recorded use aluminum. Hall’s process was directly of a l u m i n u m in the responsible for the present low price of Aluminum Company of America, architectural field i s aluminum. New Kensington, Pa. the capstone c a s t i n g on the tip of the Washington Monument, placed there as AS SOON as it was possible to produce a lightning arrestor in 1884. Because of its unprecedented aluminum inexpensively, its use in a variety of fields was imservice, i t has become the crown jewel for architectural mediately studied. The field of architecture was no exception. aluminum. In 1891, only five years after Hall’s discovery, the Venetian Building was erected in Chicago. Its elevator enclosures on Made by a chemical process from South Carolina corundum, it has successfully resisted the attacks of the elements for the first floor, the stair rail between first and second floors, the mail box, and the kick and push plates of the doors were more than fifty years. Metallurgists of the United States made of aluminum. Bureau of Standards and Aluminum Company of America, who made an examination of the casting during the recondiAn almost identical installation was made a year later in the erection of the Monadnock Building, Chicago; and in tioning of the monument in the fall of 1934, found it to have been substantially unaffected and predicted that it would 1893, when the Isabella Building was constructed in the be found in the same state after another fifty years. same city, the elevator enclosures on the first and second The cap was cast by Colonel William Frishmuth, a Philafloors, the grille work in the elevator cabs, and the stair delphia chemist, from metal made by a process of his own. railing from the first to the second floors were made of As a result of this process, he hoped to reduce the price of the aluminum. metal eventually to $1.25 a pound. But before Frishmuth In the same year a statue of Eros, by Sir Alfred Gilbert, was erected in London. This statue, cast of aluminum, was was through he found that his price was even higher than recently inspected and found to be in excellent condition Deville’s ! Heavy consumption of aluminum a t this price was imdespite forty-two years of London’s smoke and grime. possible. It was not until Hall invented his process of elecThe cornice of the Canada Life Building, Montreal, erected in 1896, was fabricated from aluminum sheet. Antrolytic reduction in 1886 that impetus was given to the use of 1128
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other cornice was erected when the Canadian Xational Office Building was constructed in Montreal in 1900, and a year later eighteen exterior beam castings of aluminum were placed in service in the Frick Building, Pittsburgh. The Citizen Building, of Ottawa, Canada, erected in 1904 and 1905, boasted an aluminum cornice.
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sible to produce complicated shapes for this purpose a t a minimum expense and in any desired length. -4s a matter of fact, many of the shapes manufactured by extrusion could have been made only Tyith great difficulty and expense if formed from sheet or cast in a mold. Painting aluminum is optional. The metal is fully protected from the attacks of the atmosphere by a thin but durable oxide coating which forms as soon as the metal comes in contact with air. Where painting is desired, however, for decorative effect, aluminum takes paint easily and holds it well. Freedom from the requirement of frequent painting reduces maintenance cost. Cornices, railings, mullions, and other ornamental parts of building facades have also proved their worth. The uniform weathering to an even gray, and the fact that aluminum does not stain adjoining masonry, have helped to make it attractive to the architect and builder. For certain special parts of a fapade, such as store fronts, street doors, and molding, metallic luster is desired. In such cases the metal, highly polished, should be suitably protected in order to obtain and to retain the best effects. The most permanent protection is given to aluminum by a glassy coat of aluminum oxide, anodically produced on the aluminum surface in a sulfuric acid bath (Alumilite process) and thoroughly sealed to render it nonabsorptive. Such oxide coatings can also be colored with adsorbed mineral pigments if desired. Plain and corrugated aluminum sheet has been successfully used for roofs and walls of factory-type buildings where corrosive fumes, such as sulfur dioxide, are present, or where salt spray exists.
THE years around the turn of the century were the years of red metal, and the progress of aluminum in the field of architecture was slow. Considerations of style demanded other materials. But when contemporary design demanded a revaluation of style and materials some ten years ago, new products of lighter colors came into vogue. The virtues of aluminum were by this time well known, and its color, which could be made either to contrast or to blend with adjacent walls, was especially desirable. The impetus for the use of aluminum was so great that in a few short years i t has been definitely established as one of the leading architectural metals. An impressive list of large buildings might be compiled in which aluminum plays a prominent part. For purposes of illustration, it will suffice to mention the Empire State Building, the Chrysler Building, Rockefeller Center, The Chicago Board of Trade Building, Marshall Field 8L Company, and the Research and Engineering Building of the A. 0. Smith Corporation, Milwaukee, whose fapades were entirely of aluminum and glass. One of the most important presentrday uses of architectural aluminum has been in the manufacture of spandrels. Inserted between the bottom of each window and the top of the one below it in a building, they enhance its artistic impression by relieving the flatness of the masonry expanse. Since the color may be made either to blend with that of the windows, 137 T H E interior of buildings aluminum has been used for when seen a t a distance, or to form a contrast, many pleasing doors, partitions, mop strips, ornamental grilles, door and effects may be obtained. cabinet hardware, electric conduit, and fixtures. Elevator A wide variety of surfaces may be produced on architectural doors and grilles and other moving parts have been made of aluminum in order to achieve desired color effects. It may aluminum because of its lightness and adequate stiffness. be etched, sandblasted, scratch-brushed, buffed, or polished; The ability to reproduce fine lines and relief on surfaces accordingly, any color from black through gray into bright accurately by the casting process has enabled the artist to metal may be produced. The lightness of aluminum produce beautiful cast-aluminum panels for decorating doors, spandrels makes them economical to erect, and their malleawalls, etc., and figures of all kinds, from statuettes to monubility facilitates attachment to the supporting steel work and ments of heroic size. Hand forging, especially with the use masonry openings, even though the contours of the latter may of dies t o give fine, be slightly irregular. sharp patterns, proALUMIXJMSPIKDRELS IS PLWEUP TO THE ELEVENTH STORY IY THE The p o s s i b i l i t y of CONSTRUCTIOK OF ROCKEFELLER CENTER,NEWYORK; STOSEWORK duces artistic decoraproducing various COMPLETE TO THE FOURTH STORY tive effects in ornatypes of ornamental mental metal work. designs and the ability to introduce ventilaT h e high thermal tion through alumii n s u l a t i n g power of num s p a n d r e l s o r aluminum foil is beobtain extra space for ing used in the conradiation or air-condis t r u c t i o n of frame tioning are additional buildings where sevreasons why they have e r a l l a y e r s of foil appealed to the archiplaced between the tect. clapboards a n d t h e plaster help to keep SPAXDRELS are t h e h o u s e cool in only one of the many summer and warm in a r c h i t ec t u r a l items win t e r . Aluminum which have been made paint on the outside of aluminum. Winof wooden buildings, dows, either casefor priming and top ment or double-hung, coats, preserves lumand window f r a m e s ber because it seals made of a l u m i n u m the surface and h a v e been w i d e l y helps to p r e v e n t used. The extrusion warping and checkprocess makes it posing. Lumber for
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home building is now often painted on all six sides before it leaves the lumber mill. Aluminum paint is also extensively used on brick walls and steel factory buildings, to brighten and protect them. I n all of these uses one is reminded of the versatility of aluminum and the ability to manufacture it by various methods. It can be cast, rolled, formed, spun, drawn, ex-
VOL. 27, NO. 10
truded, and welded. It is therefore possible to adhere to a uniform artistic scheme, whether aluminum is used for buildings large or small, new or old. Aluminum is not only a metal for modern buildings, it is also used extensively in structures which rely on period architecture for their effectiveness. RECEIVED d p r i 1 2 7 , 1915
Nickel Alloys in the Architectural Field
T
H E nickel silver a r e well classified b y Nickel alloys are finding considerable use silvers (alloys designating the nickel content, in the architectural field, particularly for such as 8 per cent nickel silver, in which t h e hardware, plumbing fixtures, architec10 per cent nickel silver, 13 per p r i n c i p a l c o n s t i t u e n t s are tural trim, and roofing. A study has corcent nickel silver, 18 per cent copper, zinc, and nickel) have related the compositions of certain nickel nickel silver, 20 per cent nickel been developed, t h r o u g h imsilver, and 30 per cent nickel proved metallurgical t e c h n i c , alloys with their colors, and has estabsilver. from the ancient Chinese alloy lished a basis for intelligent color matchMO~VEL METAL. Except as Pnktong to the numerous coming with these alloys. The compositions it appears in U. S. Government p o s i t i o n s w h i c h are available and physical properties of important specifications a s “ a c o p p e r today. During the period 221 nickel alloys are discussed. nickel alloy,” t h i s p r o d u c t B. C. to 25 -4. D. many beautiful is known o n l y b y t h i s t r a d e “white copper,”or Paktong, ornaname. G. F. GEIGER AKD R . E. CASE ments were Droduced in China, but it was n i t until late in the The International Nickel Company Inc., STAINLESS STEEL. The type eighteenth century that the alloy of nickel-chromium-iron alloy New York, N. 1. used in the architectural field is was introduced in England and c o m m o n l y known as 18-8 or Germany. The attractiveness of KA2S. In S a v y specifications it is referred to as corrosionthe product led to efforts to identify and duplicate the alresisting steel. This alloy is also covered by a large number of loy, Some fifty years later we find the almost simultaneous trade names. Of the many different types of stainless steel on appearance of Merry’s Metal Blanc (in England) and Argentan the market this 18 per cent chromium-8 per cent nickel, or German silver (in Germany). These and variations of with 0.08 to 0.20 per cent carbon, is of especial interest to the original composition are known today as nickel silvers. the architect. This type of stainless steel has a diversified Twenty-nine years ago the ores of the Creighton Mine were applicationin building construction. It is particularly adapted found to contain about twice as much nickel as copper. Colofor out-of-door metal trim, since it is highly resistant to atnel ,Vonell conceived the plan of producing a natural alloy by mospheric corrosion. refining the copper and nickel together, eliminating the separation process heretofore employed. The experiments met with successful results and the product developed was called Color and Color Matches “monel metal.” -4third group of nickel-alloyed white metals is the stainless The demand for alloys in the white range that can be used by architects in developing mild color contrasts or matches steel group, The element chromium was isolated in 1789. has led to a study (1) of the relation between color and comThe corrosion-resisting properties of the chromium-iron alloys position of a series of copper-nickel-zinc alloys in which the were appreciated in the early part of the nineteenth century nickel content ranged from 1.5 to 25 per cent and the zinc (about 1821), but not until about twenty years ago were there from 0 to 50 per cent. The effects of tin up to 8 per cent any appreciable commercial developments. Since that time and lead up to 10 per cent were also studied on certain zinc many steel manufacturers have entered the stainless field, levels. making claims for their particular analysis. These, however, are now clearly and well-defined products, with application In order to cover this range of alloys, it was necessary to compare alloys produced by the and l i m i t a t i o n well e s t a b 30 three commercial m e t h o d slished. extruded, rolled, and cast. Figu r e 1 show s the approximate Terminology ranges of nickel and zinc in the SICKEL SILVERS. This group LO cold-working, hot-working, and i s c o m m o n l y called “white casting alloys. In the cold-working alloys the metal..” I n the metal market nickel may range from 10 to 30 these are sold in the cast and /O per cent and the zinc from 5 to r o l l e d f o r m s under the trade 30 per cent, depending upon the n a m e s of R e n e d i c t M e t a l , R Ambrac A, Ambrac R, White desired physical p r o p e r t i e s , color, and tarnish resistance. B r o n z e , a n d Nickel Bronze. 0 0 /O 20 30 40 64 There are two hot-working or The latter two are chiefly used by the hardware men. zi - h C e x t r u d i n g ranges: (1) nickel zinc The various grades of nickel FIGURE1. COMPOSITIOZ~ RANGESOF NICKELSILVERS from 12 to 28 per:cent:and
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