On the permeability of oil paper

We measured the permeability of 60 different oilpaper. For the measurement of permeability of visible ray, we used the Matsuda's permeability meter; for insolation energy, the Robitzsch pyrheliograph and for ultra-violet rays the ultra-violet ray meter of C. M. O. type. The result of measurement is shown as the table No. 1 C (A is permeability of visible ray, B is that of insolation energy, C is that of ultra-violet ray). The permeability of visible ray depend upon quantity of oil which is applied for the paper, and thickness of paper chiefly; and sort of oil and manufacturing method have not big effect upon them. The permeability of insolation energy (P) depend upon the altitude of sun (h). P=a+bh There are highly correlation between permeability of visible ray (x) and that of insolation energy (y). γ=+0.776 (P