242 Journal of Experiments^ Nov. 4, 1772 



N 6 closed and sep. almost immediately, 7 closed and sep. almost immed. 

 but did not sep. wide. 5 closed and sep. again in 5" or 7". N 8 washed with 

 sp ta of wine did not close so soon as before. 



N 8 & E 4 were washed with sp. wine & a little ros. varnish & then varnished 

 with rosin. 



Sun. eve. Th. 60. Com. - 20. N. 16. 

 E. 4 did not close in i'. 

 N. 8 closed in 2 or 3". 

 N. 3 closed and sep. again immed. 



N. 8 & E. 4 were then cased in soft cement. The plates N. i & .3 were 

 varnished with lac varnish, & the plates N. 2 & E. 2 with a mixture of 6 parts 

 of varnish & i of vermilion, & afterwards baked for about 5 hours with a heat 

 part of the time up to 200, and most of the time above 150, & N. 3 & E. 5 

 were varnished in the same manner, and then cased in a cement composed of 

 14 of rosin to 12 of brick dust. N.B. E. 5 was heated in drying the varnish to 

 a great degree, so as to make it smoke violently. 

 Wed. Nov. 4 [1772]. Th. 59. N. i6J. C. - 18. 

 E. 4 closed in about 4". 

 E. 5 in 3" or 4". 



N. 8 closed and sep. again in 3 or 4". 

 N. 3 seemed to do the same rather sooner. 



Fr. Nov. 6 [1772], the plates E. i and N. 4 were varnished with rosin and 

 the plates E. 2 & N. 2 varnished with a mixture of 4 parts of rosin varnish to i 

 of vermilion & afterwards baked. They were a good deal heated both in 

 varnishing and baking, so as to be somewhat blistered. 



The plates E. 3 & N. i were also varnished before then and dried before fire. 



Sat. Nov. 7 [1772]. N. 5 and E. 8 were varnished with rosin, and N. 6 and 



E. 6 varnished with 8 parts of solut. rosin & 3 of vermilion, and then baked for 



about 2 hours with heat which part of the time rose to 146, but commonly did 



not exceed 130. 



Sun. Nov. 7 [1773*]. Th. 63. Com. 2. N. 22 J. 

 N. 3 closed and sep. wide immed. 

 N. 8 closed & sep. again in 2" or 3". 

 N. 6 rather slower. 

 N. 5 closed and sep. wide immed. 

 N. 4 more so. 

 N. 2 DO. 

 N. i D. 



E. 6 closed in 3 or 4". 



E. 8 closed and sep. again in 2 or 3" about i inch. 

 E. 3 closed and sep. wide immed. 

 E. 2 DO. 

 E. i closed and sep. again in about i'. 



* [Probably Nov. 8, 1772. See note to Art. 502.] 



