114 I Assembly 



of water, and in this solution he soaks eighty-four pounds of 

 gypsum calcined in small lumps. He exposes these lumps in 

 the open air for about eight days, till they become apparently 

 dry, and then calcines them in an oven at a dull red heat. These 

 lumps being ground and sifted, afford a fine powder, which when 

 made up into a paste with a proper quantity of water, forms the 

 petrifying ground. The mass soon concretes, and after being 

 brushed over with a thin layer of the petrifying paste, may be 

 polished with pumice, &c., in the usual way. It then affords a 

 body of great compactness and durability. If half a pound of 

 copperas be added to the solution of alum, the gypsum paste, 

 treated as above, has a fine cream or yellow color." 



We have made the above statements introductory to a notice of 

 the exhibitions in tliis department of art which were made at our 

 last fair. The principal exhibition was made by Mr. Alexander 

 Young, of the city of New- York. It consisted of the entire trim- 

 mings of a door, somewhat elaborately finished, with a variety of 

 architectural and garden ornaments. Mr. Young has been en- 

 gaged in this manufacture about two years, endeavoring to intro- 

 duce it for building purposes ; he refers to several buildings 

 which have been trimmed with it, here and elsewhere, as a sub- 

 stitute for stone, particularly to the St. Denis Hotel, a large 

 building on the corner of Broadway and Eleventh-street. 



It is claimed for Terra Cotta that, it is as strong and as endu- 

 ring as brown stone or marble ; it can be elaborately finished at 

 half the cost of eitlier ; its natural color, although it may not 

 suit the taste of every one, is far from being objectionable ; it will 

 stand the fire better than any stone used for the same purposes ; 

 paint adheres to it with great tenacity, consequently it can be 

 made to imitate other substances very closely. Mr. Young in- 

 forms us that pulverized pottery is not used in his composition, 

 but all the materials are abundant and at hand. The Gold 

 Medal was awarded to Mr. Youus?. 



'o- 



Mr. Edward Roach, of New- York, also made a good display of 

 this material, in vases, ornamented capitals, garden ornaments, &c. 



