A topical, alphabetically arranged index to volumes 26-40 including experiment station records, publications reviewed, and foreign publications. In has a 'Consolidated Table of Contents' which lists all editorial notes and publications of the experiment stations and Department of Agriculture from the referenced volumes.

Technical paper issued by the Bureau of Mines over the Bowie-Gavin process. As stated in the introduction, "this paper describes a process and an apparatus designed to recover oil from such deposits" (p. 1). The results of experiments conducted using this process are discussed. This paper includes tables, illustrations, and photographs.

Technical paper issued by the Bureau of Mines over studies on low-temperature carbonization of coal. Methods and equipment used during the studies are discussed. This paper includes tables, illustrations, and photographs.

Map of roadways of the region surrounding the Great Lakes, including Iowa, Kentucky, Wisconsin, New York, and the Canadian provinces Quebec and Ontario. The map includes major towns, bodies of water, and boundaries. The map also includes an inset map of the four Canadian road map sheets in this series bottom-center of the map. Scale [ca. 1,077,120] (17 miles to the inch).

Map of roadways in the Midwestern United States and southern portions of the Saskatchewan, Manitoba, and Ontario provinces of Canada. The map includes major towns and cities; bodies of water, including the Great Lakes; and boundaries. The map also includes an inset map of the four Canadian road map sheets in this series near the upper-right corner. Scale [ca. 1:2,217,600] (35 miles to the inch).