Transcriber’s note: Table of Contents added by Transcriber.

CONTENTS

[The Modern Occult]449
[Birds As Flying Machines]473
[Electric Automobiles]479
[The Human Body As an Engine]491
[Chapters on the Stars]500
[The Psychology of Red. (II.)]517
[The Expenditure of the Working Classes]527
[The Conquest of the Tropics]540
[Discussion and Correspondence]546
[Scientific Literature]550
[The Progress of Science]555

THE
POPULAR SCIENCE
MONTHLY

EDITED BY
J. McKEEN CATTELL

VOL. LVII
MAY TO OCTOBER, 1900

NEW YORK AND LONDON
McCLURE, PHILLIPS AND COMPANY
1900

Copyright, 1900,
By McCLURE, PHILLIPS AND COMPANY.