Precision gage measures ultrahigh vacuum levels

Ionization gage in which internally generated X rays are minimized is described. This gage permits the measurement of gas pressures in ultrahigh systems of micro-pico torr /10-18/

The Insect Galls of Cedar Point and Vicinity

The following list is based on rather careful collections made during the summer of 1914. Since the list contains many forms common throughout Ohio, I have aimed to make the synonymy fairly complete to date, as an aid to students, while the bibliography has been limited to original description (where possible) and some more recent notice which should be helpful. In the course of this work I have become deeply indebted to Mr. W. J. Kostir, of Ohio State University, while Prof. Herbert Osborn, Prof. B. W. Wells, Prof. Myron Swenk, Miss Edith Patch, Mr. Nathan Banks and others have shown me various kindnesses