Quantity of electricity communicated to whole battery'† by 584] M. 6. Electricity of 1st row of old battery was reduced to by touching 11 times by crown glass of 10 inches square. Therefore charge of 1st row to that of crown glass as 153 to 1. The first row of new battery appeared by that means to contain 107, the 2nd row 11, and the 3rd 11.4 times the charge of the same plate. The mean area of the convex coating of each jar seemed to be 14 × 121 = 175 inches, to which adding 5, id est of area of bottom, whole coating may be estimated at 180 square inches of same thickness as sides. st 10 Elect. 2 row of new battery was reduced to by touching 101 (10 (13.94 times by jar 1, therefore charge = jar 1 × 14.66, and charge mean row = jar 1 × 14·18 = 45149 inc. el. *[See Art. 506.] (13.94 [Here A seems to be the charge of one of the first 4 jars taken as unit, B that of one of the others taken as 4, and R that of the row taken as 22, the battery being 151, as in M. 2.] 585] M. 7. Whether shock of battery is sensibly diminished by imperfect conduction of the salt water in the jars. An uncoated glass jar like the coated ones was filled with fresh water and put into a glass jar of fresh water, a brass wire with knob being put into it, and a slip of tinfoil into the outer jar, it was charged till straw electrometer separated to 8 and tried by shock melter* filled [with] sea water, wires about 3 inc. dist. The water in inner jar was then changed for sat. sol. s. s.† and that in outer for about equal parts of D° and fresh water, and tried in the same manner. The shock seemed rather greater, but was plainly less when electrometer was at 7. When shock was taken without shock melter it was as strong with el. at 5 as with D° at 8. Jar 2 being charged to 8 and its electricity communicated to jar, the electrometer separated to 41. 586] M. 8. Feb. 28, 1775. Specific gravity bottle filled with salt water from torpedo trough weighed 8.4.18 by ingraved weights. Th. at 49. Specific gravity 1.0254. Being mixed with 7073525 its weight of rain water, specific gravity bottle weighed 8. 4. 1, Th. at 491, specific gravity 1.0190. Excess of specific gravity above unity of stronger is to that of weaker as 1.335 to 1. The quantity of salt in them is as 1.3524 [to 1]. Therefore the excess of specific gravity above 1 differs pretty nearly, but not quite, in as great a ratio as the quantity of salt in them. M. 9. April 1. D° Specific gravity bottle with water from torpedo trough weighed 8. 4. 22 by D° weights. April 29. Torpedo trough filled with water to within 1 inch of top, and 58 oz. salt added. Specific gravity bottle filled therewith, Th. at 70°, weighed 8.4. 12. At 54 same water weighed 8.4.161. One bottle of sea water weighed 8.4.11, Th. at 67. Another bottle weighed 8. 4. 19, Th. Do. Specific gravity bottle with rain water weighs 8.1.221. [M. 10 blank]. [This word occurs also in Arts. 622 and 637. See facsimile at Art. 622.] + [Saturated solution of sea salt.] M. 11. Rule for finding the quantity of salt in water by its specific gravity. Let the specific gravity of the solution at 46 S, and = quantity of salt solution 587. In 2nd Lane's electrometer or 1st detached do. 40 threads screw = 11⁄2 inches, or 1 division of plate = 1300 inch. Weight of the unsalted ones on June 18, and number of vibrations of a pendulum inches long, in which the electricity of 1 row of the battery was reduced from 2 to 1 by pith balls by touching with them, the ends being wrapt round with tinfoil fastened on with gum. [Mr Vernon Harcourt, in his Address to the British Association (B.A. Report, 1839, p. 48), has given extracts from Cavendish's MS. on Heat, p. 1 to p. 50, but he does not mention any page 98.] + [Art. 609.] + [So in MS. M. 13. The salted ones taken out of water two or three hours weighed June 19th. Bits of tinfoil were fastened round the ends of these pieces of wood with gum. 2B being electrified to 14 and its electricity communicated to the whole battery gave a slight shock when received through the Lime, Alder, Ash and Beech, but most through the Lime. 1R + 3B through wainscot and 2R+ 3B through deal gave much the same shock, and 3R was just sensible through Mahogany. 589] M. 14. Dimensions of coatings made to pieces of glass D, E, F, G; A, B, C, I, K, L, M, H. [See Art. 324.] M. 15. Bluish-green ground glass from Nairne called R and S. M. 16. Logarithms for calculations of these plates. M. 18. Straight piece of elect[rifying] wire, thickness 15, length 30. Increase of quantity of electricity in wire of that thickness by increasing its length from 33 to 53 inches = 4.53 inches, therefore increase of quantity of electricity in wire increase length x 226. = The two trial plates of white plate glass, which contain together 66 inches of computed power, or 66 x 16 inches of electricity, were balanced by twice the sum of the double plates A and B + 48 of additional wire 73.4+ 10·85 84.2 inc. el., therefore 10.7 inc. el. is to be allowed for the usual length of the wire. [Rules for making trial plates.] M. 19. By P. 21 [Art. 459] it should seem that the difference between two trial plates ought to be to their sum as L+S+ 20 inc. of 20 × 226 wire to L+S, or as 3.6 + The plates diameter. to 66, or as 32: 330. 1.6 (2.16 E of Nairne are to be coated with circles 2.16 in (2.19 The mean quantity of electricity in the trial plates should be 47.4 inc. if nothing is allowed for additional wire, therefore if this is A 20 increased by to allow for uncertainty, and the plate is used for B Quantity of electricity in small thin plates to be 110·1, computed power = 67.8, diameter of circles to be The trial plates to them to be made of plates I and L of that glass supposed = 1.95. = quant. el. comp. power Computed power of mean between the two plates to be 68 = = a square of 1933, the thickness of the glass being '07, therefore Small = L 1.933 long and (2.126 11. 74 broad. |