

Measures of glasses for condenser plates 297 



{From MS. N. 13.} 



592] M. r*. List of Plate glasses. 



First got. 



Made into trial plates and cased in cem[ent] of a 

 greenish colour inclining to blue with a great want 

 O f transparency. 



not used. 



coated, comp. pow. = 46. 



Same sort of glass as A and B, but from their greater 



length and breadth I could not so well judge of their 



... , 

 colour. Made up into trial plates. 



Same kind as C and D. Remains not approp. 



H is marked on side with single scratchof file, I with 2, 



and so on to L. 



Made into trial plates and broke except L. 

 More transparent than the thick plates, 

 not used. 



The thickness was measured in the middle of each side, beginning with that 

 side to right of letter, the letter being held towards eye. 



Thickness Diam. coating Comp. power 



Double plate ground glass A -3 1-82 11-04 



B -31 1-855 "'I 



I st got from Nairne. 



2 thickish plates of 8 inc. made into trial plates for 2 nd sort, called S and L. 

 Another cut into 4 pieces for trying effect of different varnishes. 

 A 4 th not used. 



2 thin ones of bluish glass coated in order to serve for trial plates to largest 

 plate, and called L and S, but not used. 



2 thick plates and i thin one rough. 



2 white glass plates from Nairne. 



4 pieces out of same piece with different sorts of surface. 



A large piece of whitish plate glass divided into 3 pieces, one used for sliding 

 trial plate. 



4 irregular shaped pieces called N, O, P, Q. [Art. 459.] 



2 thinnish pieces 5 inches square with very thin plate rosin between. 



M. 2. i piece of much the same kind fastened to piece of crown glass with 

 cement between, used for sliding plate. 



* [Here follows another series of measures oil loose leaves of different sizes.] 



