Two pairs of large corks made, one four times as heavy as the other.
Measurement of capacity of vial by touching eight or nine times
with coated plate and wire

ARTICLES

438

439

440

441

442

C, D, F close together and far asunder

Three coated plates, 1·8 diam., 18 thick

Globe and circle, 19.4 of pasteboard. Sliding plates

19 x 13

Double plate, 1.75 × 285, tried with small sliding trial plate;

Trials of wires. Single wire, 96 x 19. Two wires, 48 x 1 at 36 and 18.

Two wires, 1 x 24, at 18, 36

Coated glass compared with non-electric body with strong and weak

electricity

Coated trial plate of two plates of glass with rosin between

Real power of plate air=computed × 243 [computed is 8 times too great]

N, O, P, Q

458

459

Coated plate compared with non-electric body with strong and weak

Rosin, 3.41 x 345, compared with double B, by sliding coated plate

Side of square equivalent to trial plates

463

464

465

Results: comparison with Art. 455

Trial of spreading by machine. (Fig. 20).

Three sliding coated plates with brass sliders. Six trial plates

Feb. 4, 1772, D, E, F, G. Two double plates

E+F+G, with I, K, L, M

Feb. 5, 1772, I+K+L, with A+B+C+H, crown glass trial plates

479

480

487

488

489

490

491

492

The pages refer to the MS., the numbers of the Articles to the present edition.

PAGE OF MS.

INDEX TO ELECTRICAL EXPERIMENTS, 1773.

1-10. Spreading of electricity on the surface of glass

ARTICLES

494

11. List of thickness and coatings of some plates, see p. 27

12. Quantity of electricity in thick rosin compared with double

plate B, and in 2nd rosin with D, E and G of Nairne

500

501

PAGE OF MS.

ARTICLES

13. Q and P compared with M and K of Nairne, also green

cylinder 4, and white cylinder compared with plates of

Nairne by means of sliding trial plates

14. 1st and 2nd green and white cylinder and white jar, com-

pared with H of Nairne in usual manner

15. The same in the same way, except with addition of plate M

on the negative side in some experiments

502

503

504

16. Quantity of electricity in the two coated globes, and in the

two jars used in the machine for trying plain plates

505

.

506

507

17. Quantity of electricity in the 4 jars, and in the 5th and 6th

sliding trial plates

18. Thick rosin compared with double plate A and B, and thick

white and 2nd rosin with D, E, F and G of Nairne.

19. Thick white, 2nd rosin, D and F of Nairne and the two

double plates together, compared together; also thin white

with D and E, and D and F.

20. Whitish plate, P, Q, O, old G and thin rosin compared

with M

21. Crown A and C compared with A, B and C of Nairne

23. Whether the shock from the plate [of] air was diminished

by changing the air between them' by moving them hori-

zontally

25. Whether globe included within hollow globe is overcharged

by electrifying outer globe

26. The same thing tried by a better machine

27. Note to list of plates in p. 11.

28.

1st and 2nd sliding plates compared with double plate B;

also Q, P, O and thin rosin; old G and whitish plate com-

pared with D, E, F and M

30. Whether the charge of plate air is diminished by changing

the air between them by lifting up the upper plate

31. Trials of plate air 1, 2, 3 and 4

35. Lac plate and 4th rosin compared with D+E+F, also thin

wax with E+F, also thick wax and plate air 5 with D

36. Lac and 4th rosin with D+E+F, also thin wax with D + E,

38. Breaking of electricity through thin plates of lac, experi-

mental rosin, and dephlegmated bees wax

also thick wax, 2nd rosin and first made rosin and plate

air 5 with F

39. The quantity of electricity in a Florence flask tried with

and without a magazine

521

41. Computed power of above flask

522

42.

As it appeared by the foregoing experiment that the Flo-

rence flask contained more electricity when it continued

The two flat conductors between which the plate of air lies, or, in modern

language, the electrodes.

CONTENTS.

xvii

PAGE OF MS.

43.

47.

ARTICLES

charged a good while than when charged and discharged

immediately, it was tried whether the case was the same

with the coated globes

Diminution of shock by passing through different liquors

Whether force with which bodies repel is as square of re-

dundant fluid tried by pith balls hung by threads

523

524

525

51.

Whether the charge of plate E bears the same proportion

to that of another body, whether the electrification is strong

or weak, tried by machine for Leyden vials.

526

53.

Plain wax and 3rd dephlegmated wax with E+F, and 5th

rosin with double plate A and B. Also small ground crown

with D +E+F, and large do. with C

527

54.

55.

K, L and M, compared with D+E+ F at distance and close

together; also large ground crown with C and small one

with D+E+F; also 3rd dephlegmated wax and plain wax

with E+F; also 5th rosin with double B

K+L+M compared with A, B and C ; also A+B+C with H

56. K+L+M compared with B, with electrification of different

strength

57. K+L+M with A, B, and C ; also D+E+F with K, L

and M; also small ground crown with K, L and M, and

D+E+F, and large ground crown with A, B and C, and

K+L+M

On the light visible round the edges of coated plates on

charging them

59. Crown A and C and large ground crown with C; also 3rd

dephlegmated wax, plain wax and sliding plate 3 with E+ F;

also 2 double plates with E, F and D

60. Charge of the triple plate, the three plates A, B and C

placed over each other with bits of lead between coat-

Whether the charge of plate D bears the same proportion to

that of another body whether the charge is strong or weak,

tried with machine for Leyden vials .

535

62. H with slits and a crown glass with oblong coating, com-

pared with white cylinder, also A and C with slits compared

with B

536

65. Crown with slits and H with do. compared with white

cylinder, and A and C with oblongs compared with B

537

67. Experiment of p. 61, tried with small ball blown to the end

of a thermometer tube; also fringed rings on plate of

crown glass, &c.

69. Whether charge of Leyden vial bears the same proportion

to that of another body when the electrification is very

weak as when it is strong; tried by communicating the

electricity of small pieces of wire to tin cylinder and to

D and E

538

539

ARTICLES

PAGE OF MS.

70. Lane's electrometer compared with straw and paper electro-

meter.

71. Crown and H with slits compared with white cylinder;

also on the excitation of electricity by separating a brass

plate from a glass one

540

541

73. Whether the middle of three parallel plates communicating
together is much overcharged on electrifying the plates

74. Charge of A, B and C laid on each other without any

coatings between; also charge of 1st thermometer tube

75. Lane's electrometer compared with straw and paper electro-

meter; also charge of plate rosin with brass coating made

to prevent spreading of electricity

542

543

544

76. Second thermometer tube; also comparison of charge of

cylinder used in p. 69 with D + E

545

77. Charge of second thermometer tube; also that of rosin

plate with brass coating; also that of A, B and C laid on

each other without coatings between

78. Quantity of electricity in plate D compared with that of tin

circle of 36" and one of 30", by machine for trying simple

plates.

79. Charge of plate of experimental rosin designed for com-

paring plate of glass and rosin, tried both when warm and

when cold

546

547

548

80. Whether charge of glass plate is the same when warm as

when cold

549

81. Crown with slit coatings and H with oblong compared

with white cylinder; also second thermometer tube with

D+E+F

550

82. Quantity of electricity in plate D, and rosin with brass

coatings, compared with that of tin circle of 36", and one of

30" by machine for trying simple plates with different de-

grees of electrification

83. Charge of compound plate of glass and rosin

551

552

85. Circle of 18" compared with double plates; also plate D,

plate air, and the two double plates compared with circles

of 36" and 30′′

86, 90 & 91. The same with addit. four small rosin plates

554

87. Whether the four rosin plates contain same quantity of

electricity when close together as when at a distance, tried

by machine for Leyden vials.

555

89. Whether charge of white glass thermometer tube is the

same when hot as when cold

556

92. Allowance for connecting wires in p. 86, &c.

557

93. Whether charge of the four rosin plates is the same when

close together as when at a distance. Also on excitation of

electricity by separating brass plate from glass one.

558

94. Comparison of Henly's, Lane's, and straw electrometer

559