.

.

.

.

On Ventilation

307

TO MISS MARY STEVENSON.

Method of contracting Chimneys. Modesty in

Disputation

324

John Ewing to B. Franklin. 4 January, 1770.

Transmitting Observations of the Transits of Venus

and Mercury. - Proposal for an Observatory in

Philadelphia

326

To Nevil MASKELYNE. 12 February, 1770.

Containing an Account of Professor Winthrop's Ob-

servation of the Transit of Mercury over the Sun,

November 9th, 1769

328

To MICHAEL HILLEGAS. 17 March, 1770.

Respecting covering Houses with Copper 329

JOHN EWING TO B. FRANKLIN. 14 June, 1770

330

To SAMUEL RHOADS. 26 June, 1770.

On securing Houses from Fire

332

To THOMAS PERCIVAL.

On the different Quantities of Rain which fell at

different Heights over the same Ground

336

W. SMALL TO B. FRANKLIN. 10 August, 1771.

Opinions of the Ancient Physicians respecting Ca-

tarrhs or Colds

339

To M. Le Roy. 20 April, 1772.

Intended French Voyage to the North Pole. - Mr.

West, President of the Royal Society. - Messrs.

Banks and Solander

341

To Joseph Priestley. 4 May, 1772.

Electrical Experiments.— Imperfection of the Abbé

Nollet's Electrical Machine. - One on an improv-

ed Construction sent to M. Le Roy

:: 342

Joseph PRIESTLEY TO B. FRANKLIN. 3 June, 1772.

Experiments on Air

344

Joseph PriestLEY TO B. FRANKLIN. 1 July, 1772.

Curious Experiments on Air, and Discoveries of

various Properties

346

VOL. VI.

.

.

.

.

.

.

JOHN WALSH TO B. FRANKLIN. 12 July, 1772.

Experiments for ascertaining the Electrical Proper-

ties of the Torpedo

348

J. B. TODERINI TO B. FRANKLIN. 15 August, 1772.

Giving an Account of a Work published by him,

entitled “ Filosofia Frankliniana"

351

Answer to M. Dubourg's Queries respecting the Armonica.

8 December, 1772

352

Some Directions for drawing out the Tones from the Glass-

es of the Armonica

353

On the Stilling of Waves by Means of Oil

355

To HUMPHRY MARSHALL. 14 February, 1773.

On the Spots in the Sun; Dr. Wilson's New Hy-

pothesis

368

M. DE SAUSSURE TO B. FRANKLIN. 23 February, 1773.

Conductors of Lightning. — Project of the Royal

Society to ascertain the Attraction of Mountains.

Volcanic Eruptions. - Experiments on the Torpedo 371

JOHN WINTHROP TO B. FRANKLIN. 4 March, 1773.

Dr. Priestley. — Effects of Lightning

375

To M. DUBOURG. 10 March, 1773.

On the Causes of Colds

378

To M. Le Roy. 30 March, 1773.

Mr. Wilson's Opposition to Pointed Conductors. -

M. Le Roy chosen a Member of the American

Philosophical Society .

379

To M. DUBOURG.

Observations on the prevailing Doctrines of Life

and Death

381

To William DEANE. 11 April, 1773.

• A new-invented Carriage Wheel. — Explosion of

Melted Iron and Glass Drops in Water. - Stove

for consuming the Smoke .

383

To M. DUBOURG. 4 May, 1773.

Concerning Dr. Stark

385

To M. LE Roy. 22 June, 1773.

Hospitals.—Effect of Cold Air on Diseases 385

LI

C

.

.

.

.

387

387

397

399

402

404

.

406

TO M. DUBOURG. 29 June, 1773.

Inquiries on the Causes of Taking Cold

Preparatory Notes and Hints for writing a Paper concern-

ing what is called Catching Cold

To SAMUEL COOPER. 7 July, 1773.

Stoves for Public Buildings

To BENJAMIN Rush. 14 July, 1773.

Colds produced by Contagion.

- Various Causes

of Colds

To Thomas PERCIVAL. 25 September, 1773.

Unwholesomeness of Manufacturing Establishments.

- Moist Air not unhealthy

Joseph PRIESTLEY TO B. FRANKLIN. 26 Sept. 1773.

New Experiments on Air

To John INGENHOUSZ. 30 September, 1773.

Torpedo. - Magnetic Needle. - Nairne's Electri-

-

cal Machine. - Magazines at Purfleet

Joseph PriesTLEY TO B. FRANKLIN. 14 Oct. 1773.

Experiments on Alkaline Air

ERASMUS DARWIN TO B. FRANKLIN. 24 Jan. 1774.

Communicating a Philosophical Paper

TO THE MARQUIS DE CONDORCET, 20 March, 1774.

Answers to Questions on Philosophical Subjects

To John BAPTIST BECCARIA. 20 March, 1774.

English Translation of Beccaria's Book. - Ex-

-

periment to show that Electricity does not pass

through a perfect Vacuum

To JOSEPH PRIESTLEY.

Effect of Vegetation on Noxious Air

To Joseph PRIESTLEY. 10 April, 1774.

On the Inflammability of the Surface of certain

Rivers in America

On the Aurora Borealis

Joseph PRIESTLEY TO B. FRANKLIN. 27 Sept. 1779.

Vegetation of Plants in Water

PIETRO TURINI To B. FRANKLIN. 18 Sept. 1780.

Communicating Intelligence of a new Work on

409

.

.

410

411

413

414

.

.

.

.

.

the Method of Erecting Conductors of Lightning 424

To EDWARD NAIRNE. 13 November, 1780.

Proposing a slowly sensible Hygrometer for cer-

tain Purposes

426

TO THE MARQUIS TURGOT. 1 May, 1781.

On a new-invented Stove

432

To Felix Vice d'Azyn. 20 July, 1781.

On the Long Retention of Infection in Dead

Bodies after Sepulture

433

Felix Vice d’Azer to B. FRANKLIN. 23 Aug. 1781 437

To John INGENHOUSZ. 2 October, 1781.

On Conductors of Heat

438

An Account of Toads found enclosed in Solid Stone 441

To the ABBÉ SOULAVIE. 22 September, 1782.

On the Theory of the Earth

443

John INGENHOUSZ to B. FRANKLIN. 29 Nov. 1782.

Experiment for burning Wire

448

EDWARD NAIRNE TO B. FRANKLIN. 2 Dec. 1783.

A Hygrometer on a New Construction. — M. De

Luc's Hygrometer

449

To David RITTENHOUSE. 15 December, 1783.

On the Comet seen in Yorkshire

451

To John INGENHOUSZ. 16 January, 1784.

On Balloons, and their probable Importance 452

To BENJAMIN VAUGHAN. 29 April, 1784.

Fire supposed to exist in the State of a Subtile

Fluid

454

Meteorological Imaginations and Conjectures. May, 1784 455

Loose Thoughts on a Universal Fluid. 25 June, 1784 458

To John INGENHOUSZ. 29 April, 1785.

Clock with three Wheels.- Gravitation of Bodies 461

To David Le Roy. August, 1785.

Improvements in Navigation. – Observations on

the Sails and Cables of Vessels; the Models for

their Construction; Means of preserving them

from Accidents at Sea; Methods of giving Mo-

tion to Boats. Gulf Stream. Precautions to

.

.

those who are about to take a Voyage at Sea.

- General Reflections on Navigation

463

Appendix to the above Letter. Remarks upon the Nav-

igation from Newfoundland to New York

496

To John INGENHOUSZ. 28 August, 1785.

On the Causes and Cure of Smoky Chimneys 505

Description of a new Stove for burning Pitcoal, and con-

suming all its Smoke

543

Description of an Instrument for taking down Books from

bigh Shelves. January, 1786

562

To BENJAMIN Vaughan. 31 July, 1786.

On the Effects of Lead upon the Human Con-

stitution

564

On Thermometers. 13 September, 1786

567

WILLIAM HERSCHEL TO B. FRANKLIN. 19 Feb. 1787.

With a Catalogue of new Nebulæ and Clusters

of Stars

569

To M. Le Roy. 18 April, 1787.

On Balloons. - Pigeons killed by Lightning

-

570

NEVIL MASKELYNE TO B. FRANKLIN. 3 March, 1788.

Concerning Churchman's Theory of the Varia-

ation of the Magnetic Needle

571

To JAMES BOWDOIN. 31 May, 1788.

Queries and Conjectures relating to Magnetism

and the Theory of the Earth.

. 574

Description of the Process to be observed 'in making

large Sheets of Paper in the Chinese Manner,

with one smooth Surface

577

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.

VOL. VI.

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