The same, with pencil attachment (old style), $24.00.
Aneroid Barometer (for meteorological work), $14.00-$16.00.
Note.—Much cheaper aneroids can be purchased, and may be used to some advantage in the simpler observations in schools.
Mercurial Barometer (Standard United States Weather Bureau pattern), complete with attached thermometer, vernier, etc., $30.00-$33.00.
Note.—The above instruments, as used by the United States Weather Bureau, are made by H. J. Green, 1191 Bedford Avenue, Brooklyn, N. Y. The prices are those given in Green’s latest catalogue.
Mercurial Barometer. New improved form, especially designed for school use. Mounted on mahogany back. Scale engraved on aluminum. Divisions of scale on metric and English systems. No vernier, $5.75.
(L. E. Knott Apparatus Co., 14 Ashburton Place, Boston, Mass.)
Thermograph (designed by Dr. Daniel Draper, of New York). Consists of a bimetallic thermometer in a case which carries a disk, with a chart upon its axle instead of hands like the ordinary clock. A pen (resting on the face of the disk) registers the fluctuations of temperature as the chart is carried around. Sizes, 14 × 20 inches, $30.00; 10 × 14 inches, $15.00. This instrument may be purchased of H. J. Green.
Thermograph. Self-recording thermometer (as adopted by the United States Weather Bureau), made by Richard Frères, of Paris. Records continuously on a sheet of paper wound around a revolving drum, which is driven by clock-work inside. Standard size (without duty), $30.00.
Barograph. Self-recording barometer (as adopted by the United States Weather Bureau), made by Richard Frères, of Paris. Similar in general arrangement to the thermograph. Standard size (without duty), $27.60.