THE TECHNICAL WORLD MAGAZINE, published the seventeenth of each

month preceding the date of issue, is a popular, illustrated record of progress in science,

invention and industry.

PRICE: $1.50 per year, in advance; single copies, 15 cents. Fifty cents additional for

points in Canada, except Newfoundland, which requires foreign postage. Foreign postage is

$1.00 a year additional.

HOW TO REMIT: Send money by draft on Chicago, express or postoffice. money

order.

THE EDITORS invite the submission of photographs and articles on subjects of modern
engineering, scientific, and popular interest. Prompt decision will be rendered and payment
will be made on acceptance. Unaccepted material will be returned if accompanied by
stamps. While the utmost care will be exercised, the editors disclaim all responsibility for
manuscripts submitted.

THE TECHNICAL WORLD MAGAZINE, published the seventeenth of each

month preceding the date of issue, is a popular, illustrated record of progress in science,

invention and industry.

PRICE: $1.50 per year, in advance; single copies, 15 cents. Fifty cents additional for
points in Canada, except Newfoundland, which requires foreign postage. Foreign postage is
$1.00 a year additional. Send money by draft, express or postoffice money order.

THE EDITORS invite the submission of photographs and articles on subjects of modern
engineering, scientific, and popular interest. Prompt decision will be rendered and payment
will be made on acceptance. Unaccepted material will be returned if accompanied by
stamps. While the utmost care will be exercised, the editors disclaim all responsibility for
manuscripts submitted.