1 00 Composition to set 



and elaborate apparatus, and one which would allow of the 

 article being furnished at a reasonable rate, will be requisite, 

 and, no doubt, easily found. 



Dr. Motherwell's Report. 

 The different experiments were made on graduated pro- 

 portions af lime and clay, as under : — 



5 parts lime with 1 part clay. 



2 



3 



4 



., 5 



n .... 1 



JO .... 1 



The proportions which appear to me to answer best after 

 immersion in water for eight days are the two last, and 

 particularly the 10 with 1. In making these experiments, 

 the manipulation is conducted in a way which could not 

 be followed on a larger scale, as the operation would be 

 both too tedious and expensive : I give, however, the exact 

 manipulation, and shall point out the most economical way 

 to proceed on the large scale. 



Having neither stone-lime nor chalk, I used shell-lime 

 fresh burnt and slaked. The clay which I used was first well 

 dried, pulverized, and sifted ; the clay and lime were then 

 mixed in the proportions mentioned above, and well 

 triturated with pestle and mortar, first in the dry way, and 

 then with a gradual addition of water till made into a stiff 

 paste ; the compound was next made into balls and calcined 

 at a strong heat, in a manner similar to the burning of 

 bricks. These balls were then again pulverized and sifted 

 through a fine hair sieve, in order to bring the powder to a 

 degree of fineness equal to that of Koman cement. The 

 composition was at this stage of the process fit for use. 



