.

.

To CADWALLADER COLDEN.

Conjecture as to the Cause why Ships in crossing

the Atlantic have longer Passages in sailing west-

ward than in sailing eastward .

74

CADWALLADER COLDEN TO B. FRANKLIN.

Answer to the foregoing Letter respecting the

Sailing of Ships across the Atlantic

76

To JARED Eliot. 16 July, 1747.

Linseed Oil. Northeast Storins. Origin of

Springs in Mountains. — Petrified Shells in the

Appalachian Mountains.- Observations on a Tariff

Law

79

To JARED Eliot.

Experiments in the Culture of Grass in Meadows 83

To THOMAS HOPKINSON. 1747.

On the Vis Inertiæ of Matter

87

To CADWALLADER COLDEN. 6 August, 1747.

Baxter's Book on the Vis Inertiæ of Matter.

Manufacture of Electrical Apparatus. - Colden's

Philosophical Treatise

93

A Conjecture as to the Cause of the Heat of the Blood

in Health, and of the Cold and Hot Fits of some

97

To PETER COLLINSON.

Magical Square of Squares

100

To PETER COLLINSON.

Magical Circle

104

To JARED ELIOT. 13 February, 1749 - 50.

Northeast Storms begin at the South. — Account

-

of a Copper Mine.- Subscriptions for an Acad-

emy in Philadelphia

105

To CADWALLADER COLDEN. 28 June, 1750.

Electrical Papers and Experiments. - James Logan 109

To JARED Eliot. 25 October, 1750.

Inquiries respecting the Mode of Planting Hedges 111

TO JARED ELIOT. 10 December, 1751.

Remarks on Husbandry

112

Fevers

-

114

118

120

121

.

123

127

136

CADWALLADER COLDEN TO B. FRANKLIN. 20 May, 1752.

Concerning Theories of Light

JOHN PERKINS TO B. FRANKLIN. 3 August, 1752.

Respecting the Number of Deaths in Boston by

Inoculation

To John PERKINS. 13 August, 1752.

Concerning the Smallpox in Philadelphia

To CADWALLADER COLDEN. 14 September, 1752.

Remarks on Mr. Colden's Theory of Light.

Translation of Electrical Papers into French

CADWALLADER COLDEN TO B. FRANKLIN. 24 Oct. 1752.

Cause of the Cohesion of the Particles of Matter. -

Concerning a Translation of a German Writer's Re-

marks on Mr. Colden's Philosophical Principles

Physical and Meteorological Observations, Conjectures, and

Suppositions

JOHN PERKINS TO B. FRANKLIN. 16 October, 1752.

On Water-Spouts

JOHN PERKINS TO B. FRANKLIN. 23 October, 1752.

Further Remarks on Water-Spouts

W. MERCER TO B. FRANKLIN. 11 November, 1752.

Description of a Water-Spout at Antigua

To John PERKINS. 4 February, 1753.

Water-Spouts and Whirlwinds compared

TO JAMES Bowdown. 28 February, 1753.

Relating to the Transit of Mercury in 1753

To JARED Eliot. 12 April, 1753.

Properties of Water. Notice of the Author's

Writings in France

John PERKINS TO B. FRANKLIN. 14 May, 1753.

Shooting Stars

John PERKINS TO B. FRANKLIN.

Water-Spouts and Whirlwinds .

Observations on the Meteorological Paper; by a Gentleman

in Connecticut

Observations in Answer to the Foregoing; by B. Franklin

138

.

.

a

143

145

.

Observations on the Meteorological Paper; sent by Cad-

wallader Colden to B. Franklin

177

Answer to the foregoing Observations; by B. Franklin . 180

Extracts from Dampier's Voyages, relating to Water-Spouts 183

WILLIAM SHERVINGTON TO B. FRANKLIN. 20 June, 1753.

On the Transit of Mercury across the Sun, May

6th, 1753, observed at Antigua

187

To Thomas Clap. 8 November, 1753.

On Smeaton's Air Pump

188

JAMES BOWDOIN TO B. FRANKLIN. 12 November, 1753.

Concerning the Light in Sea-Water

190

M. DALIBARD TO B. FRANKLIN. 31 March, 1754.

Intelligence on Philosophical Subjects

193

CADWALLADER COLDEN TO B. FRANKLIN. 2 April, 1754.

Water-Spouts. — Wind generated by Fermenta-

tion.- Winds blowing in contrary Directions 195

CADWALLADER COLDEN TO B. FRANKLIN. 2 April, 1754.

New Theory of the Motion of the Planets best

suited for calculating Astronomical Tables.-Abbé

Nollet's Book

197

CADWALLADER COLDEN TO P. Collinson. 28 May, 1754.

On Water-Spouts

199

To PETER COLLINSON. 25 August, 1755.

Account of a Whirlwind in Maryland

201

To John LINING. 14 April, 1757.

On Cold produced by Evaporation

203

JOHN BARTRAM TO B. FRANKLIN. 12 Noveinber, 1757.

Relating to a remarkable Aurora Borealis

211

To John PringLE. 6 January, 1758.

On the different Strata of the Earth

212

To John LINING. 17 June, 1758.

Experiment with Ether for producing Cold by

Evaporation.- Water kept cool in hot Countries.

- The human Body cooled by Evaporation.

The Surface of the Earth and Vegetation cooled

in the same Manner

213

.

218

219

222

225

.

231

232

234

239

To PETER FRANKLIN. 7 May, 1760.

On the Saltness of Sea Water

To ALEXANDER SMALL 12 May, 1760.

On the Northeast Storms in North America

To Miss MARY STEVENSON. 11 June, 1760.

On the Effect of Air on the Barometer, and the

Benefits derived from the Study of Insects

To Miss MARY STEVENSON. 13 September, 1760.

On the Bristol Waters, and the Tide in Rivers

To Miss MARY STEVENSON. 30 March, 1761.

Tides in Rivers

To Miss MARY STEVENSON. 10 August, 1761.

Salt Water rendered fresh by Distillation. --- Meth-

od of relieving Thirst by Sea Water

To Miss MARY STEVENSON. 20 September, 1761.

Tendency of Rivers to the Sea. - Effect of the

Sun's Rays on Cloths of different Colors

On Fire. 1762

To David Hume. 24 January, 1762.

On the Method of securing Houses from the Ef-

fects of Lightning

DAVID HUME TO B. FRANKLIN. 10 May, 1762.

Remarks on the Mode of constructing Lightning-

Rods. - Compliment to Dr. Franklin as a Philo-

sopher and a Man of Letters

To John Baptist BECCARIA. 13 July, 1762.

Describing a new Musical Instrument composed of

Glasses

To OLIVER Neave. 20 July, 1762.

Respecting the best Mediums for conveying Sound

To JOHN PRINGLE. 1 December, 1762.

Relating a curious Instance of the Effect of Oil

on Water

Congelation of Quicksilver.-Cold produced by Evapora-

tion. 26 February, 1763 ·

JOHN CANTON TO B. FRANKLIN. 29 June, 1764.

The Melting of Metals by Lightning not a cold Fu-

241

.

243

245

250

253

256

260

.

263

269

273

275

277

278

.

sion. - Compressibility of Water and other Fluids

EZRA STILES TO B. FRANKLIN. 20 February, 1765.

Thermometrical Experiments

To LORD KAMES. 2 June, 1765.

On the Harmony and Melody of the old Scotch

Tunes

To PETER FRANKLIN.

On the Defects of Modern Music

Joseph PRIESTLEY TO B. FRANKLIN. 21 September, 1766.

Relating to a History of Electricity. — Curious

Experiments with an Electrified Chain

To George CROGHAN. 5 August, 1767.

Conjecture as to Elephants being Natives of Amer-

ica

To M. DALIBARD. 31 January, 1768

To CADWALLADER Evans. 20 February, 1768.

On the Colica Pictonum, and Pernicious Use of

Lead in Distilleries

To LORD KAMES. 28 February, 1768.

.

On Chimneys

To Sir John PRINGLE. 10 May, 1768.

On the Difference of Navigation in Shoal and Deep

Water

To OLIVER NEAVE.

On the Art of Swimming

To M. DUBOURG.

Modes of Swimming. - Answer to Inquiries. —

Swimming with a Kite

To M. DUBOURG. 28 July, 1768.

On the free Use of Air

A Scheme of a New Alphabet and Reformed Mode of

Spelling, with Remarks and Examples

Petition of the Letter Z

TO JOHN WINTHROP. 11 March, 1769.

Telescope and Books for Harvard College

To M. DUBOURG. 30 August, 1769.

Introducing Dr. Lettsom

280

283

286

290

294

295

304