of Domien, an Electrician and Traveller. — Con-

jectures respecting the Pores of Glass. — Origin of

the Author's Idea of drawing down Lightning. -

No satisfactory Hypothesis respecting the Manner

in which Clouds become electrified. Six Men

knocked down at once by an Electrical Shock.

Reflections on the Spirit of Invention

347

To M. DALIBARD. 29 June, 1755.

Beccaria's Work on Electricity. - Sentiments of

Franklin on pointed Rods, not fully understood in

Europe. - Effect of Lightning on the Church of

Newbury, in New England. — Remarks on the

Subject

355

To John Pringle. 21 December, 1757.

On the Effects of Electricity in Paralytic Cases 359

To Thomas HUBBARD. 28 April, 1758.

Electrical Apparatus. — Description of a Battery · 361

To William HEBERDEN. 7 June, 1759.

On the Electricity of the Tourmalin

363

E. KINNERSLEY TO B. FRANKLIN. 12 March, 1761.

Experiments on boiling Water, and Glass heated by

boiling Water. - Doctrine of Repulsion in elec-

trized Bodies doubted. — Electricity of the Atmo-

sphere at different Heights. - Electrical Horse-

race.- Electrical Thermometer. — In what Cases

the Electrical Fire produces Heat. — Wire length-

ened by Electricity. - Good Effect of a Rod on

the House of Mr. West, of Philadelphia ,

367

To E. KINNERSLEY. 20 February, 1762.

Answer to some of the foregoing Subjects. — How

long the Leyden Bottle may be kept charged. —

Heated Glass rendered permeable by the Electric

Fluid. - Electrical Attraction and Repulsion. -

Reply to other Subjects in the preceding Paper.

Numerous Ways of kindling Fire. — Explosion of

Water. - Knobs and Points

. 378

Accounts from Carolina (mentioned in the foregoing

Letter) of the Effects of Lightning on two of the

.

395

396

.

398

403

403

.

405

406

407

Rods commonly affixed to Houses there, for secur-

ing them against Lightning. 1 November, 1760

Mr. William Maine's Account of the Effects of the

Lightning on his Rod, dated at Indian Land, in

South Carolina, August 28th, 1760.

Remarks by Benjamin Franklin

To Miss MARY STEVENSON. 22 March, 1762.

Concerning the Leyden Bottle

Electrical Experiments on Amber. 3 July, 1762 .

JOHN WINTHROP TO B. FRANKLIN. 29 Sept., 1762.

New Observation relating to Electricity in the At-

mosphere

ALEXANDER SMALL TO B. FRANKLIN.

Flash of Lightning that struck St. Bride's Steeple

To PETER FRANKLIN.

Best Method of securing a Powder Magazine from

Lightning

To Thomas Ronayne. 20 April, 1766.

On the Electricity of the Fogs in Ireland

Mode of ascertaining whether the Power, giving a Shock

to those who touch either the Surinam Eel or the

Torpedo, be Electrical

Addition, 12 August, 1772, in Consequence of the Ex-

periments and Discoveries made in France by Mr.

Walsh, and communicated by him to Dr. Franklin

Of Lightning, and the Methods (now used in America)

of securing Buildings and Persons from its mis-

chievous Effects. September, 1767

John WINTHROP TO B. FRANKLIN. 6 January, 1768.

St. Bride's Steeple

To John WINTHROP. 2 July, 1768.

On Conductors for protecting Houses from Light-

ning. — Singular Kind of Glass Tube

E. KINNERSLEY TO B. FRANKLIN. 13 October, 1770.

On some Electrical Experiments made with Char-

coal

409

412

413

414

.

419

419

.

426

tricity

To Major Dawson, ENGINEER. 29 May, 1772.

On the Security of the Powder Magazines at Pur-

fleet.

427

Report on Lightning Conductors for the Powder Maga-

zines at Purfleet. 21 August, 1772

430

Experiments, Observations, and Facts, tending to sup-

port the Opinion of the Utility of long, pointed

Rods, for securing Buildings from Damage by

Strokes of Lightning

435

Description of a Portable Apparatus, invented by Mr.

John Canton, for the Purpose of easily demonstrat-

ing Dr. Franklin's fundamental Principles of Elec-

446

To M. DUBOURG. 10 March, 1773.

On the Analogy between Magnetism and Electricity 450

M. DUBOURG TO B. FRANKLIN. 25 March, 1773.

On the Choice of Glass for the Leyden Experiment 453

To Messrs. DUBOURG AND DALIBARD.

Concerning the Mode of rendering Meat tender by

Electricity

456

To M. DUBOURG. 1 June, 1773.

In Answer to some Queries concerning the Choice

of Glass for the Leyden Experiment

459

To John WINTHROP. 25 July, 1773.

On Conductors of Lightning

461

Queries on Electricity, from Dr. Ingenhousz ; with An-

swers by Dr. Franklin

462

T. JOHN INGENHOUSZ.

An Attempt to explain the Effects of Lightning on

the Vane of the Steeple of a Church in Cremona,

August, 1777

467

The Leyden Phial, and M. Volta's Experiment

476

T. JOHN INGENHOUSZ. 16 May, 1783.

On an Electrical Experiment

477

On the Shock by the Electric Bottle, and the Density

of Glass.

478

479

To EDWARD NAIRNE. 18 October, 1783.

On his patent Electrical Machine, and the Effects of

Lightning on the Eyes of Animals killed by it

To John INGENHOUSZ. 29 April, 1785.

Effect of an Electrical Shock

To PROFESSOR LANDRIANI. 14 October, 1787.

On the Utility of Electrical Conductors

480

482

APPENDIX TO THE PAPERS ON ELECTRICITY.

No. I. Watson's Abstract of Franklin's Electrical Experi-

ments and Observations

487

No. II. Letter from the Abbé Nollet to Benjamin Franklin 493

No. III. Speech of the Earl of Macclesfield, President of

the Royal Society, on the Occasion of awarding to

Franklin a Medal for his Discoveries in Electricity . 499

No. IV. Letter from John Baptist Beccaria to Benjamin

Franklin.

505

No. V. Letter from Professor Thorbern Bergman, of Up-

sal, to Benjamin Wilson

513

No. VI. Letter from M. Dubourg to M. de Lor. Parallel

between the Theories of Franklin and Nollet.

514