INTENDED FOR THE

INSTRUCTION AND ENTERTAINMENT

* OF

1

PRINTED

VOL. IV. OF PNEUMATICS.

"Conversation, with the habit of explaining the meaning of words,
"and the structure of common domestic implements to children, is the
sure and effectual method of preparing the mind for the acquirement of
⚫science." EDGEWORTH'S PRACTICAL EDUCATION.

76

FOR BALDWIN, CRADOCK, AND JOY,
PATERNOSTER ROW; AND R. HUNTER (SUCCESSOR
TO J. JOHNSON), ST. PAUL'S CHURCH-YARD,

Conversation

CONTENTS

TO

VOL. IV.

I. Of the nature of Air: Wind, Air in Mo-

tion: how Fish swim.......

.......................

II. Of the air-pump: Dr. Darwin's Descrip-
tion; Barometer-gauge; Resistance of
the Air; Philosophical Hammer........

III. Of the Torricellian Experiment: Experi-

.............

Page

.་......་.. ........

ments......

............................. ******....

IV. Of the Pressure of the Air: No such

principle as Suction

V. The same Subject continued: The Trans-

ferrer; Hemispherical Cups; Fountain

in Vacuo; Bottle broken by the Pres-

sure of the Air; Mercury passes

through the Pores of Wood............................... 37

VI. Of the Weight of Air.....

46

VII. Of the Elasticity of Air: Experiments:

Cupping...........

22

29

-56

Conversation

VIII. Of the Compression of Air: Artificial

fountains: Condensing Syringe and

common Squirt compared................. 69,

IX. Miscellaneous Experiments on the Air-

pump: why Sinoke and Vapours ascend:

Lungs glass, &c...

87,

X. Of the Air gun and Sound: Air-guns ille-

gal; Magazine Wind-gun; Air, the

medium of Sound; Conductors of

Sound; Striking Experiment.........

XI. Of Sound: Thunder; Gunpowder; Musi-

cal Chords; how far Sound can be heard;

Velocity of Sound and Light; Uses to

which this Knowledge may be applied.. 97

XII. Of the Speaking Trumpet: Speaking

Figures, &c...................

XIII. Of the Echo: Line of Incidence and Re-

flection; Principle of the Echo.......... 118

XIV. The same Subject continued: Echoes at

Glasgow, Brussels, Thornbury Castle,

Milan, &c.; Echo applied to measuring

inaccessible Distances; Whispering Gal-

lery at St. Paul's; Musical Glasses.... 130

XV. Of the Winds: Smoke-jack, Trade Winds,

&c.; Experiments; Storms; Velocity

of Wind; Table............

Page

..........

79

111

140

XVI. Of the Steam-engine: when and by whom

invented; Mr. Watt's Improvement.... 156

XVII. The same subject continued................ 169

A

Conversation

XVIII. The same Subject, and Papin's Digester:

Whitbread's Brewery; Accidents by

Steam

................ 178

XIX. Of the Barometer: Fluctuation of the

Mercury; the Vernier: Rules for pre-

dicting the changes of the Weather..... 189

XX. Application of the Barometer to the

measuring of Altitudes........

201

XXI. Of the Thermometer: Fahrenheit's Scale 211

XXII. The same subject; Wedgewood's Scale
of Heat; Fahrenheit and Reaumur's
Thermometers compared..........

....... .....

...........

Page

221

XXIII. Of the Pyrometer and Hygrometer....... 230

XXIV. Of the Rain-gauge, and Rules for judging

of the Weather............

APPENDIX.

Of Air, as a Vehicle of Heat and Moisture. Of

Rain-Dew-Meteoric Stones......

...........

242

253