678 Transactions of the American Institute. 



machines, especially devised for the purpose ; and it has been found that 

 a combined pressing and rolling motion secures the best results. 



To speak of the application of hydraulic cements, they are especially 

 useful for the manufacture of building stone. In Europe, especially 

 in England, numerous buildings of the kind have been erected ; in 

 London, for instance, the celebrated College of Surgeons, in Lincoln's 

 Inn Fields. In this country, buildings constructed of cement stone 

 made by the process of George A. Frear, have been erected in Brook- 

 lyn, Toledo, Buffalo, Chicago and New Orleans. In the various 

 cities of the west upwards of 300 buildings have been constructed of 

 this stone during the last three years, and they have satisfactorily 

 stood the test of the severe climate which is more severe in the west 

 than on the Atlantic coast. In Brooklyn fifty-nine buildings are in 

 process of erection at the present time. We are informed that in the 

 great fire in Chicago the Frear stone stood the test better than any 

 other building material in that city. Every stone left standing in tho 

 walls was found to be in perfect condition, and builders are now draw- 

 ing away the blocks to be used in the re-erection of other structures. 



Messrs. Bandman and Jaffe in New York are about going to erect 

 entire buildings with chimneys and cooking place of beton or concrete, 

 by which name an aggregate of gravel or broken stone, lime and 

 hydraulic mortar is commonly designated. A building of this kind 

 was first constructed in 1830 by the architect Lebrun in Alby 

 (Department du Tarn, France), and since then thousands of small 

 and large houses have been constructed of beton in England and on 

 the continent. According to Mr. Joseph Tall, of London, the prin- 

 cipal advantages of this system of building seem to consist in the 

 following : 



1. The cost is only half of the construction in brick and mortar. 



2. The walls are impervious both to wet and damp. 



3. The chimney flues being round and smooth, internally, smoking 

 chimneys and defective draught will be effectually prevented. 



4. No bond timber is required for joists ; no wood lintels nor brick 

 arches over doors, windows or other openings. 



5. The walls can be increased in thickness every inch, instead of 

 being obliged to be made of four and a half, nine or thirteen, and a 

 half inches, as in brickwork. 



6. The doors and windows are built into the wall and have a light 

 and neat appearance, as any moulding may be moulded thereon while 

 the work is progressing. 



