Of the UNIVERSE, and the feveral SYSTEMS of

the WORLD,

DIALOGUE III.

7.

Of the fallacious Reafoning on which the PTOLO-

MAIC HYPOTHESIS depends,

II.

A View of the demonftrative Proofs of the FALSITY

of the PTOLOMAIC HYPOTHESIS, as reprefented

in a NEW PLANETARIUM,

DIALOGUE V.

A Brief Account of the SOLAR SYSTEM,

DIALOGUE VI.

16.

21.

DIALOGUE X.

Of the EARTH; confidered as a PLANET, 55.

Of the PLANET MARS,

DIALOGUE XI.

Of the PLANET JUPITER,

DIALOGUE XII.

Of the PLANET SATURN,

VOL. I.

A

65.

72.

78.

DIALOGUE

XIII.

On the Ufe of the GEOCENTRIC PLANETARIUM

by Means of an Ephemeris,

DIALOGUE XIV.

85.

On the Ufe of the STELLATED PLANETARIUM, 95,

DIALOGUE XV.

Of the COMETS,

On the Use of the COMETARIUM,

99:

DIALOGUE XVI.

107.

PART II.

The Speculation of the STARS continued,

DIALOGUE V.

124:

131.

DIALOGUE IV.

Of an ECLIPSE of the SUN,

DIALOGUE VI.

Of an ECLIPSE of the MOON,

DIALOGUE VII.

Of the Boundaries, and Number of Eclipfes,

Times of the Year when they happen,

DIALOGUE

VIII

Reflections on the Immenfity of the Universe, and of

the Plurality of Worlds,

162.

PART III.

The Doctrine of the SPHERE; or, a general

Defcription of the Circles thereof,

DIALOGUE

II.

Of the HORIZON, and its Various Ufes,

168.

173.

DIALOGUE III.

Of the GENERAL MERIDIAN, and the Degrees of

Latitude,

DIALOGUE IV.

177.

Of the EQUINOCTIAL, and the DEGREES of LON-

GITUDE,

DIALOGUE V..

180.

Of the ECLIPTIC, and the Longitude and Latitude,

of the Heavenly Bodies,

184.

Of the COLURES, TROPICS, POLAR-CIRCLES, and

DIALOGUE VI.

The Seafons of the Year explained by the ORRERY:

And first the SPRING,

DIALOGUE X.

Of SUMMER,

215.

222.

On the Nature, Form, and Magnitude of the

ATMOSPHERE, or Body of AIR,

249.

DIALOGUE II.

Of EXPERIMENTS to fhew the natural Production

of AIR,

DIALOGUE III.

256.

Of the Doctrine of WIND. Its Nature, Ufe, and

Causes,

DIALOGUE IV.

265.

Of the Nature and Generation of METEORS, 273.

DIALOGUE V.

The Nature and Generation of METEORS continued.

Of SNOW, HAIL, LIGHTNING, THUNDER,

Aurora Borealis, &c,

283.

DIALOGUE VI.

On the Nature, Phænomena, and Experiments of

ELECTRICITY,

DIALOGUE VII.

294.

The Experiments on ELECTRICITY continued, 314.

DIALOGUE VIII.

Of the Nature, Conftruction, and Use of the

BAROMETER,

321.

DIALOGUE IX.

Of the Nature and Ufe of THERMOMETERS, and

their Variety of different Conftructions,

DIALOGUE X.

332.

Of the Nature and Ufe of HYGROMETERS, 347.

DIALOGUE XI.

Of the INVENTION and CONSTRUCTION of the

AIR-PUMP,

DIALOGUE XII.

353.

The Experiments on the AIR-PUMP continued, 380.

DIALOGUE XIII.

The Experiments on the AIR-PUMP continued, 394.

DIALOGUE XIV.

The Nature, Structure and Ufe of the CONDENSER,

MERCURIAL GAGE, AIR-GUN, and VENTI-

LATOR,

404.

THE

THE

YOUNG GENTLEMAN AND LADY's

PHILOSOPHY.

DIALOGUE I.

INTRODUCTION.

Euphrofyne.

pleafing Difcourfe you entertained us with last Night, that I know not which is greateft, my Joy in feeing fo near a Relation after so long Abfence at College, or the Happiness I conceive will redound to me, and the Family, from the great Abilities and Improvements you've there acquired.

Cleonicus. Dear Euphrofyne, as I have been very induftrious in improving my Time and Talents at College; fo if any Satisfaction or Happiness refult from thence to any Perfon, and especially to yourself, dear Sifter, I fhall think myself highly compenfated. Your remarkable Difpofition to reading, I fee, with the greatest Pleasure, has given you an elegant Tafte, and rendered you capable of understanding, and converfing with Perfons on fuch Subjects as come but too rarely on the Carpet in any Converfation, especially that of your Sex.

Euphrof. I fuppofe, Brother, you intend to make me a Compliment: Indeed I love reading very much, but wifh I were more capable of improving by it. Philofophy, I mean the Knowledge of natural Things in general, is what I fhould be greatly pleafed in the Study of, were it VOL. I.

B

2

not