抄録
The characters of Sima-Sand and Tsu-Sand which the author discovered were inspected. The results obtained were as follows : Sima sand No. 1 is uniform in grain and has the best characters, which is, if added Bentnite etc., improved to become a remarkable material of synthetic sand. Grains of Sima-sand No. 2 and 3 are not uniform a little. Sima-sand No. 2 is coarser in grain but No. 3 is more fine. Tsu-sand is worse than Sima-sand. Tsu-sand No. 1 is too fine in grain to use and Tsu-sand No. 2 is generally available. The difference of grain distribution was recognized by the position of the sand stratum, and has a certain tendency, by which uniform sand in grain can be obtained. (M. I.)
