OF THE

FRANKLIN INSTITUTE

OF THE

State of Pennsylvania

AND

MECHANICS' REGISTER.

DEVOTED TO

MECHANICAL AND PHYSICAL SCIENCE,

CIVIL ENGINEERING, THE ARTS AND MANUFACTURES,

AND THE RECORDING OF

AMERICAN AND OTHER PATENTED INVENTIONS.

EDITED

BY THOMAS P. JONES, M. D.

KEMBER OF THE AMERICAN PHILOSOPHICAL SOCIETY, OF THE ACADEMY OF NATURAL
SCIENCES, PHILADELPHIA, THE AMERICAN ACADEMY OF ARTS AND SCIENCES,
MASSACHUSETTS, THE NATIONAL INSTITUTION FOR THE PROMOTION

OF SCIENCE, WASHINGTON, CORRESPONDING MEMBER OF THE
POLYTECHNIC SOCIETY OF PARIS, AND OF THE CHILIAN
AGRICULTURAL SOCIETY, SANTIAGO.

NEW SERIES.

VOL. XXV.

PHILADELPHIA:

PUBLISHED BY THE FRANKLIN INSTITUTE, AT THEIR HALL,
F. TAYLOR, WASHINGTON CITY; G.' CARVILL

& CO., NEW YORK; AND JOSEPH H.

FRANCIS, BOSTON.

1840

NUS

JOURNAL

OF THE

FRANKLIN INSTITUTE

OF THE

State of Pennsylvania,

AND

MECHANICS' REGISTER.

JANUARY, 1840.

Practical and Theoretical Mechanics and Chemistry.

Reply to the Remarks of Dr. Hare, on the Essay of Wm. Gries, M. D., relating to the supply of rooms with heated air.

TO THE EDITOR OF THE JOURNAL OF THE FRANKLIN INSTITUTE.

SIR,-I owe it to myself, and to the cause of science, that I should reply to Professor Hare's remarks, published in the October number of your Journal, on my essay, published in the August No. of the same Journal. The reason that I have not attended to this sooner is, that I was absent from my home for two months, and did not see his paper till the last week in Decem. ber.

When I prepared my essay I wished to occupy as little space in your valuable Journal as possible. The principle appeared to my mind so very plain and simple, that I expected the merely indicating it, to men of science, would be sufficient: but I must have been exceedingly obscure in my language, when such a scientific mind, as the learned professor's, has entirely mistaken my views.

When I first saw his communication, my idea was to leave it, without further comment, to the scientific public, to compare our papers, and to decide upon them; but the public is so much governed by the authority of great names (not having sufficient leisure to examine for themselves) and the professor's being so deservedly established, by his many claims to priority of discovery, that I fear my humble essay would be entirely overlooked; for I have no other ground than the soundness of my position, and the strength of my arguments to sustain it.

The opinion generally entertained, with regard to introducing heated air into apartments, was that it is immaterial in what direction we bring it in, so that it is near the floor-that it would then diffuse itself as well with one mode of introduction as another, and this opinion I attempted to combat in VOL. XXV.-No. 1-JANUARY, 1840..

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