Note 8 — Chapter I
Reading edition
Silicate Roll Blackboards, which are perfectly flexible and can be rolled tightly, like a map, without injury, may be obtained from the New York Silicate Book Slate Co., 20 Vesey St., New York. They are made in various sizes, about the most convenient for use in noncommissioned officers' schools is No. 3, three by four feet—price $2.