190 
Mean. 
Grains. 
Maximum. 
Grains. 
Edisto Sea Island 
142-5 
Sea Island (good quality) 
900 ... 
1320 
Benquella 
218-8 
Sea Island Cotton 
102-6 ... 
203 0 
L T plauds 
10T5 .... 
212-6 
Surat (fair Dhollerah) 
105-8 ... 
215-5 
Maranham 
107-1 ... 
187-2 
Egyptian (fair) 
108-0 ... 
157-9 
Mobile 
118-8 ... 
172-3 
Egyptian 
127-2 .... 
191-0 
Orleans 
139-7 ... 
289-4 
Pernambuco 
140-2 .... 
..... 2511 
Surat (Dhollerah) 
141-9 .... 
236-6 
Maranham (good middling) 
142-9 .... 
242-4 
Queensland 
147-6 .... 
246-2 
Orleans (good middling) 
147-7 
264 0 
Surat (middling Comptah) 
163-7 .... 
280-2 
PHYSICAL AND MATHEMATICAL SECTION. 
November 12th, 1863. 
E. W. Binnky, F.R.S., F.G.S., Vice-President of the 
Section, in the Chair. 
A Paper was read by Mr. J. Atkinson, F.G.S., “ On the 
Construction of Bi-focal Lenses for Spectacles.” 
The author stated that he had for many years been obliged 
to wear concave glasses to remedy what is called “ short- 
sight.” About seven years ago lie found that from some 
change in his eyes he could no longer read with the concave 
glasses which he used for looking at distant objects. Not 
being able to see things distinctly at the distance of even a 
few feet without spectacles, and at the same time being 
obliged to take off his glasses to read or to look at any thing 
close at hand, was such an inconvenience that he sought to 
