M. 13. The salted ones taken out of water two or three hours

June 19th Bits of tinfoil were fastened round the ends of these pieces of wood with gum.

2B being electrified to 1

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.
Logarithms for calculations of these plates.
Do.

M. 16.

M. 17.

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 +

1.6

to 66, or as 32 : 330.

(2.16

The plates E of Nairne are to be coated with circles 2.16 in (2.19

diameter.

F

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

is used for

increased by to allow for uncertainty, and the plate B

20

В

Quantity of electricity in small thin plates to be 1101, 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

= a square of 1933, the thickness of the glass being 07, therefore

=

68:

Small = L)
Large = IS

= 1.933 long and

(2.126

broad.

1.74

[From this table it appears that D is supposed to contain 36 "inc. el." Now, by Art. 655, D contains 26-3 "globular inches," which is equal to 41 "circular inches," or 36.7 "square inches".]

[Specimen of Measurements of thickness by dividing engine.]

590] 2nd rosin plate, [Art. 371, 500] mean diameter 5.6.

591] M. 32. Measures of thickness of crown glass [Arts. 370, 500] measured in the middle of each 16th square part, the numbers being placed in the same situation as the squares.

C. At 1.881 the knobs coincided.

1.944 48 51 48

48 52 52 44

53 53 46 38

53 46 40 34

mean 1.947, thickness 066.

•184

8.04

Н

•062

4.35)

⚫066

4.36

К

⚫063

4.34

L

⚫068

4:37)

*055

8.68

GHIKIM

First got.

Made into trial plates and cased in cem[ent] of a greenish colour inclining to blue with a great want of 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.

up into trial plates.

Made

Same kind as C and D. Remains not approp.
It is marked on side with single scratch of
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. Diam. coating. Comp. power.

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

Another cut into 4 pieces for trying effect of different varnishes.
A 4th 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 1 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. 1 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 on loose leaves of different sizes.]

[The weights in 1st & 2nd column are in ounces, pennyweights and grains (Troy), in the 3rd and 4th in decimals of an ounce, and the 5th is the specific gravity. The number 9-84973 is the logarithm of the number of cubic inches in an ounce of glass.]

M. 4. [Gives 1st the length of each side of each piece of glass, and the distance between the middles of opposite sides to hundredths of an inch.

2nd the thickness at each corner and middle of each side to thousandths of an inch.

3rd specific gravity and mean thickness deduced from it for plates A to M of Nairne.

[The thicknesses given in Art. 324 are those calculated from the weight in and out of water and the measurement of the sides. They are greater than the measured thicknesses in every case.]

594] M. 6. Measures of thickness & of green glass cylinder.

Longest cylinder: a mark made with file near middle.

The 1st column is the distance in inches of the point to which cylinder is immersed in water from the scratch.

[Art. 314.]