Abstract
The author constructed a newly designed hair hygrograph. Although this instrument is seemingly similar to the F. Richard's one, but has two cranks and one connecting bar in place of cams (see Fig. 1 and Fig. 2), and it can also record the relative humidity in uniform scale on a recording chart Excellence of this instrument is in the simplicity of the construction and in the smooth action due to small friction, therefore it may be made more easily than the old one.
