The spark passed through garden wire seemed rather redder than that through the silk wire, but the difference was not remarkable. The spark passed through garden wire seemed about as strong as that through about 8 of an inch of saturated solution, but sensibly redder. 644] The reel was altered, and some copper wire silvered stretched upon it. The mean circumference of reel = 44·05 × 2 √2. There were 12 rows of glass bars and 42 rounds of wire on each row, therefore whole length of wire = 88·1 × √2 × 12 × 42 = 62790 inches. This weighed 5747 grains. Consequently there are 10.93 inches to 1 grain. The shock received through this wire felt vastly stronger than the simple shock; the shock of tube 2 received through the wire with electrometer at 14 seeming little less strong than the simple shock with the same tube and the electrometer at 13, but considerably stronger than with electrometer at 11. 645] The above-mentioned wire compared with sat. sol. by sound. 1:46. Seemed more brisk. The light of salt water white, the other very red. 1.7 Do 9.5 I believe rather less, certainly a sharper sound, but I believe rather 646] 74 of sat. sol. in tube 17 is equivalent to 29623 inches of copper wire, 9.984 inches of which = 1 grain. 7.25 of sat. sol. in do. = 62790 of copper wire, 10.93 of which grain*. = 1 RESULT. 647] 1773, p. 92 [Art. 557]. The connecting wire to the two plates of 9-3 inches contains 14 inc. el. The connecting wire to the rosin plates of p. 86 [Art. 554], should contain rather more in proportion to its length than this, id est, rather more than 28. By p. 93 [Art. 557], the 4 rosin plates seemed to contain about inc. el. less when placed close together than at dist. Let us therefore suppose that the charge of 2 rosin plates placed close together with connecting wire between them exceeds twice the charge of 1 plate by 28 inc. el., and that the charge of 4 plates exceeds 4 times the charge of 1 by 2 times that quantity, or 7 inc. el. Let us suppose, too, that the charge of the 2 double plates A & B with connecting wire exceeds twice the charge of 1 by 28. N.B. By inc. el. is meant circular inches of electricity. [These logarithms are correct only to three places of decimals, they should be 0.1875 and 9-8122. See Note 35.] 650] [Results of Art. 649.] By Mar. 13. [Art. 553.] Double plate = circ. 18+ 11 sq. inc., or 12 inc. el. 2 doub. +2.67 inc. el. without allowance for com 651] All the following are with allowance. 1 ros. circ. 9.3+ ·85. circ. 1812 ros. 63 = = = 4 ros. + 1.44 circ. 9·3 × 2 + 1·07. 652] *If charge circle is greater than it would be if placed at a great distance from any other body in ratio of a: a − - 36, charge circ. of 18 should exceed in ratio of a: a- 18 and so on. Therefore, if we suppose a = 167, (36 (9.89 charge circ. 18 should exceed its true charge by 2-31 |