78 Transactions of the American Institute. 



two and a half j^ears, and from the well known fact that the 

 atmosphere does oxidize the compound, the undersigned are unwil- 

 ling to advise the American Institute to give it the indorsement of 

 a first premium; yet in viewing the great industry, perseverance 

 and laudable ambition of the promoters of this roofing, to meet a 

 great public want, would advise all the encouragement that justice 

 to the Institute and a fair, impartial dealing with the whole public, 

 that a premium of the third degree be awarded. Nothing in the 

 whole range of contributions to the public wants is so difiicult to 

 supply as a plastic or flexible roofing, at a cheap rate. With a very 

 few exceptions, all good buildings have been covered with tin, 

 copper, slate or tile. All these will wear over ten years. Next 

 in value and durability, is asphaltum, over saturated paper and 

 covered with gravel, and judging from the experience of the past, 

 the plastic slate is next, but this article has been onh-- about two 

 years before the public, and where its application has been in three 

 coats on tin, it is found to be oxidized, and all its adhesive property 

 destroyed, and to flake off in brittle friable particles. This is the 

 case on a roof recommended as a sample roof by Vannorden & 

 Co., foot of Nineteenth street, at Ne well's saw mill. On one of 

 the sheds, the roof looks well, but has not "turned into slate." 

 Where the roof is applied in winter, the roof does not harden, and 

 always where applied in tliick coats, retains its soft pitchy charac- 

 ter, except on the surface. 



No. 254. (Smith & Speth.) A sample of bricks for the con- 

 struction of chimneys. This is an admirable invention, a decided 

 improvement in the forming of an ordinary flue. There is but one 

 joint upon each layer of brick, while the next layer laps, maldng 

 great security against fire, and a decided improvement in draft, by 

 reason of the smooth inside and rounded substitute for corners. 

 This invention will simplify the construction of chimneys, and 

 without adding to the cost, will also lessen the size of the jamb a^id 

 space in the room. It should have a premium aAvarded, to cnccillr- 

 age its author. 



No. 40, from Bishop Gutta Percha Co., large assortment of gutta 

 percha articles, principally adapted to marine telegraphing, worthy 

 of premium. It is a fact that no other known substance has been 

 found as a substitute for use in forming submarine ca])les, and until 

 the discovery of this curious substance by Dr. Montgomery in 

 1843, no submarine could have been worked. This simple tact is 

 worthy of entry into the managers' report, if reference is made to 



