39 
Ordinary Meeting, December 24th, 1878. 
J„ P. Joule, D.C.L., LL.D., F.RS., President, in the Chair. 
“ Note on the Intensity of Moonlight,” by Harry Grim- 
SHAW, F.C.S. 
At the meeting of this Society held on the 26th of 
November of the present year, some remarks were made 
upon the relative intensity of moonlight, daylight during a 
thick fog, and the diffused light of the electric arc. 
The opinion was then expressed by some members that it 
was very doubtful whether it was possible to read printed 
type of anything like a small size by the brightest moon- 
light in this country. 
The light of the moon on the 8th of the present month 
(December) being of considerable intensity, I took the 
opportunity of making the experiment, which I have pre- 
viously, at different times, performed more roughly, with 
sufficient accuracy to form some standard of comparison. 
The result was that I found it possible to read with cer- 
tainty a still smaller type than I had previously known it 
possible to peruse. 
The types on which I experimented were those of a 
newspaper, and known technically by the printers as 
“ minion,” “bourgeois,” and “nonpareil.” These are all 
smaller than the letters of the “Proceedings” of the Society, 
which I believe is called “small pica.” The two first are 
what are ordinarily used for such printing as that of news- 
papers and the cheaper periodicals, whilst the last (“non- 
pareil”) is a very small letter indeed. The last paragraph 
of this note is printed in the type in question. The printed 
matter in the “minion” and “bourgeois” letter was read with 
Peoceedings— Lit. & Phil. Soc.— Yol. XYIII — No. 5.— Session 1878-9. 
