The writer points out the importance of selection of grits in artificial stone, and reports on the new stone improved at the Tomakomai work.
Points of improvements are as follows :
1. Adoption of mechanical stamping method with the sandrammer, instead of the present hand stamping,
2. Practice of reinforced concrete with iron rings in place of iron frames. He, then, claims the following merits thereof :
a) Increase of uniformity, hardness, and mechanical strength of stone,
b) Decrease of untimely stone breaks,
c) Betterness of properties of groundwood,
d) Increased output, etc.
