TO MAJOR DAWSON, ENGINEER. 29 May, 1772.

On the Security of the Powder Magazines at Pur-

fleet.

Report on Lightning Conductors for the Powder Maga-

zines at Purfleet. 21 August, 1772

427

430

435

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

Description of a Portable Apparatus, invented by Mr.

John Canton, for the Purpose of easily demonstrat-

ing Dr. Franklin's fundamental Principles of Elec-

tricity

To M. DUBOURG. 10 March, 1773.

446

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

To M. DUBOURG. 1 June, 1773.

In Answer to some Queries concerning the Choice

of Glass for the Leyden Experiment

456

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

TO JOHN INGENHOUSZ.

An Attempt to explain the Effects of Lightning on

the Vane of the Steeple of a Church in Cremona,

August, 1777

The Leyden Phial, and M. Volta's Experiment

On the Shock by the Electric Bottle, and the Density

of Glass .

478

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 .

APPENDIX TO THE PAPERS ON ELECTRICITY.

479

480

482

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.

No. IV. Letter from John Baptist Beccaria to Benjamin

Franklin

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

sal, to Benjamin Wilson

499

505

513

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

between the Theories of Franklin and Nollet

POLITICAL PAPERS

DURING AND AFTER

THE AMERICAN REVOLUTION.