1869.] Outcalfs Patent Elastic Joint Iron Hoof. 537 OUTCALT'S PATENT ELASTIC-JOINT IRON ROOF. TT7E present, in this number, a view VV of the new Skating Kink, at the S. E. corner of Twenty-first and Race streets, in this city, which extensive structure is covered with the material called Outcalt's Patent Elastic Joint Iron, of which Mr. William S. Irwin, the agent, ]S T o. 406 Library street, and Reed street, below Tenth, Philadelphia, has kindly given us all desirable in- formation as to its employment and ap- plication. The extensive use made by Civil Engineers, as well as Architects, of metal roofing for depots, markets, and all buildings requiring extensive cover- ings, gives this new invention a pre- eminent claim on the notice of all con- cerned in building, not alone for such extensive public structures as the great Skating Rink here illustrated, as well as all other places of vast capacity, but likewise as an admirable material for the roofing of all dwellings, as well as public buildings, civil and ecclesiastic. The serious defect in metal roofs, hitherto, was the tendency to leakage, owing to the effects of contraction and expansion. This the present invention completely overcomes, as may be at once seen on reference to the accompanying cuts : Fig. 1 represents a single sheet of the metal, ready for application. It is shaped, for the purpose, by scrolling cylindrical tubes on the two outer longi- tudinal edges of the sheet, of which the one tube is formed by an upward, and the other by an inverted, roll of the edge. All the sheets being alike, the upward edge-roll of any one sheet fits, somewhat loosely, in underneath the in- verted edge-roll of any other sheet ; and, by thus hooking one edge-roll inside another, all is rendered complete, when considered from gable to gable. If taken from eaves to ridge, the end connection of the sheets is obtained by inter-fitting flat, erect and inverted hooks, formed at the respective tops and bottoms of the sheets ; and represented, in section, at Fig. 2. Fig. 3 shows a transverse section of the sheets, and the manner in which Fij. 3 their edge-rolls are locked together. The scroll, or partly open tube, on each edge, is about three-fourths of an inch in diameter ; and it will at once be ob- served, that it is perfectly water-proof. i ¥ i
