Technical paper issued by the Bureau of Mines over gas masks developed for gasoline and petroleum vapors. Descriptions of different types of gas masks developed are presented. This paper includes tables, photographs, and illustrations.

Technical paper issued by the Bureau of Mines over the development of gas masks designed for fighting fires. The characteristics of the different types of masks in development are presented. This paper includes tables, illustrations, and photographs.

Report issued by the Bureau of Mines discussing fuel recovery from uncondensed vapors. As stated in the introduction, "this paper aims to show the possibility of increasing the gasoline yield from the crude by the recovery of considerable gasoline that is now lost by remaining uncondensed" (p. 1). This report includes tables, illustrations, and photographs.

From introduction: The production of gypsum is one of the oldest industries in Canada, and in point of gypsum output Canada ranks third among the countries of the world. Gypsum was discovered in the Maritime Provinces at a very early date, but there is no authentic record..of production until about 1822, when gypsum was mined on a small scale in Ontario. Since.then the production has grown slowly but steadily to more than a million tons. In 1928 the output was 1,205,846 short tons, valued at $3,622,007.