15~ Monthly Meetin~ o f the Frankl in Znslilute.

red hot iron at 117~ degrees, has heat enough to convert one cubic inch of water into 1700 cubic inches of steam.

tIence it appears extremely easy to produce explosl.ons fl'om . . . . . " toyed b,~ t)er kms steam throwing water on not iron, as ntoeeu ~s p" d ';,

, . . • . . . . ~ - r o n ~ r e r I n a n ~,I gun. If that ~,entleman s generators nan oven no o~ ~ . "- dinarv boilers, the would have been destroyed by one-tlm'd of the power winch he produced by throwing water on thetr red hot n on. and strong even as they were, they would have exploded had he pumped in a sufficient uantit of water, without ivin~, vent to the steam q Y g o produced,

A cubic foot of hot iron by being reduced to $~2 degrees, would furnish heat suft~eient to convert a cubic foot of" ice cold water into lS,600 gallons of steam, at atmospheric pressure: and a single square toot of boiler-iron, ~ of an inch thick, if only at a bright red heat, has caloric enough to make 88 gallons of steam. I t is probably not very uncommon tot boilers to become so destitute of water, that 10 or 15 square feet become red hot. This surface, by losing only half its heat, would produce steam enough in addition to that already ex!sting, to explode almost any boiler. •

£he sudden coolin~ of a part of the boiler, no doubt weakens it very much, and henc~we find some boilers in their rupture follow. ing the water line, which line was probably made by a fresh supply

" " " " ,~ I water u on the of water, or by a motion of the steam boat ratsm~, t ~e p heated iron of one side.

The explosions which have occurred about the period of coming to, or leaving a w!lart, may be attributed to the boztt's being' throwil partly on one side, either in turning, in striking the wharf~ or under the wc'ight of passengers shifting their position, so that the water is thrown ,q)on hot iron of the boiler.

The co,c/u~ion to which I come~ i% that a considerable proportion of the explosions which occur, is occasioned by water being thrown on highly heated iron. The proper preventives~ are, care in engi. neers, and such construction of boilers, that the part exposed to the greatest heat will not be soonest laid hare, nor a large surface either suddenly laid bare, or suddenly covered by water: also to throw the water into tl~e bottom of the boiler, rather than b y a jet into the up. per part.

F R A N K L I N I N S T I T U T E .

2~lonthb] Meeting. THE stated monthlymeeting of the Institute was held at their Hall

on Thursday evening, February ~4, 18:31.

The Mechanics' dournal, or ,qrtisans' Miscellan~ of Inven- tions, E:vperiments, Projects~ and Improvements in the ~se.

ful Jt,'ts.

~ o n t M y Meeting o f the Frank l ln Ins t i tu te . 157

B y 1V[r. Zachariah Allen. 7trite ~denee of zllcetwaffes as applied to the present ivr6vrove-

_ m enta in the us~ul 3rts in Europe and in tire United ~tates. By M r . Josiah Copley.

Zetter from the Secretary of the Treasury, transmitting the i~.formation required by the House qf Representatives in re.

. o v - -

alton to the ~rowth and mamtfaeture of Silk, adalqted to the .. different parts of the Union. ~ - ~

By the Board of Managers of the Institute, for 18S0. 1 ~ • " , - - 1 ~ " recks, Elementa~re de Physique )Sxperementale, Tar J. thot~

Vol~. 1 and ;L By l?rofessor A. 1). Bache.

Catalogue of the O/]icers aml Students of the Untverst~. of I cn~zsylvama, January, 1831.

The corresponding secretary laid on the table the following works~ received in exchange tot the Journal of the Institute, viz.

The 2tlechanies' Magazine, and Journal of Public hffernal hn- proven~enls, for January, 2 copies.

Journal o f the Philadelphia College of Pharmacy, for January. Jtmerican dnnals of )2ducatlon a~ul Instruction, and Journal of

Literary Institutions, for February. The 2tfagazine o)2" Usefiul and J~ntertaining .lt~wwledge, for Jan-

uary. Bulletin de la SocHtg d'Encouragement pour l'lndustrie Nation.

ale, for August, 18~0. Professor A. D. Bache stated, on the part of the committee on ex-

plosions of steam boilers, that tim preparatory arrangements for ex- perl en ts had been made, and apparatus for further prosecuting the objects o f their appointment was m progress.

Professor Johnson from the same committee stated, that the e0m- mittee had taken measures to obtain specimens of American iron for the purpose of experimenting on the strength of the dift~rent kinds of that material employed in the formation of steam boilers.

Mr. 1). t[ . Mason made some remarks on the application of the power of steam engines to locomotive carriages.

Thomas Earle, Esq. read a paper "on the causes of some Explo- sions of Steam Boilers," which, after some remark% was referred to the commit tee on publications.

The following queries were proposed tbr discussion, and ordered to be en tered on the minutes.

1st. T h e subject of rapid and slow motions of boats in abrading the banks of a canal.

~nd. W h a t are the relative advantages of stationary and locomo- tive power, in propelling carriages on planes of any elevation?

$d. W h a t are the best means of securing the boilers, cylinders, and all other parts of steam engines, whether employed for stationary purposes, for navigation, or for locomotive carriages~ against loss of power by radiation and conduction?

THOMAS FLI~TCnZR~ ~e~ President. J. H. BULKT.~¥, Recording Secretary.