REPORT OF THE DIRECTOR AND STATE GEOLOGIST 1903 123 



old lime plaster is being largely driven from use. The slightly 

 gray color of some of the ^NTew York State plaster was long 

 urged as an insuperable objection to its use, but, when mixed 

 with sand and fiber, it makes a superior wall plaster. 



The advantages of cement plaster over lime plasters are, first, 

 it sets more rapidly and dries out more rapidly than lime plaster, 

 so that there is less delay in finishing buildings, second, as a 

 nonconductor of heat, it is valuable as a fireproofing material, 

 third, any desired tint can be given the plaster by mixing it with 

 coloring material at the time the plaster is prepared for putting 

 on the wall, fourth^ less mortar is required to cover the sanle 

 amount of wall space, fiftli, it may be used in large slabs in 

 wainscotings, as a substitute for marble and other ornamental 

 stones, sixth, it is less liable to shrinkage than other plasters, 

 so that few cracks are to be seen in the walls covered with this 

 material. 



Among the objections to the use of this plaster are its greater 

 cost and the facility with which sounds are conveyed through 

 walls of this material. 



As just stated, the cement plasters have certain fireproof 

 qualities, and these are increased by certain admixtures. Mixed 

 with asbestos, it has been used in plastering the inside of fire- 

 pots in stoves; in the walls and fioors of fireproof buildings it 

 has been used mixed with ashes and asbestos. In some cases 

 the plaster of paris is mixed with wood fiber and other ma/terial 

 and molded into blocks which resemble in form and appearance 

 the hollow terra cotta fireproofing material. These are of 

 coarse used in exactly the same way as the terra cotta. 



The use of plaster of paris and the cement plasters in making 

 ornamental ceilings and stucco work in general is becoming very 

 widespread with the regulation of the set of the plaster. For 

 this purpose, instead of laying the plaster on lath surfaces, the 

 stucco is molded in the shop of the artist and is nailed or other- 

 wise fastened to the timbers or girders of the walls or ceiling. 

 The separate pieces are made in specially prepared molds of 



