File:The London, Edinburgh and Dublin philosophical magazine and journal of science (1896) (14756148406).jpg

Identifier: londonedinburgh5421896lon (find matches)
Title: The London, Edinburgh and Dublin philosophical magazine and journal of science
Year: 1840 (1840s)
Authors:
Subjects: Science
Publisher: London : Taylor & Francis
Contributing Library: Smithsonian Libraries
Digitizing Sponsor: Biodiversity Heritage Library

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
k. This arrangement proved inconvenient, and more-over it rendered difficult the intended measurement of theinitial temperature of the gas. Accordingly I modified theapparatus in such a manner as to make the heater entirelyindependent of the calorimeter proper. In fig. 2 (reducedin the ratio 2-J : 1) DP R/R represents the heater (I shallcontinue to call it so, although, when used at low tempera-tures, it acts really as a cooler); S the cooler ; both are fixedto a separate support E, which stands on a heavy base E.This part of the apparatus may thus be used in conjunctionwith different calorimetric vessels. * I think that the method described here, of weighing gases in a com-pressed condition, could be advantageously employed in accurate deter-minations of the density of some gases under atmospheric pressure. Forthat purpose the weighed flasks ought to be dischnrged into an emptyreceiver of known capacity and temperature, provided with a mercurymanometer. A. W. Witkowski on the Fig. 2.
Text Appearing After Image:
Thermodynamic Properties of Air. 9 The calorimeter K—a vessel of thin sheet silver, capacityabout 250 cub. centims., weight 98*310 grammes—rests onthree pointed glass feet inside a double-walled brass enclosureZ, protected on the outside by sheets of paper and cotton-wool ; the space between the walls is filled with water.Through several openings in the double sheet-brass cover ofthe enclosure there are introduced into the calorimeter :—(1) the cooler S, (2) the stirrer M, the oscillations of whichare maintained by a heavy pendulum (not shown), (3) thethermometer T. The thermometer T, an excellent instrument furnished byG. Fontaine of Paris, was divided in 0*02 degr. (from —0o,5to +0°-6 and + ll°-5 to +22° 3). It has been standardizedwith reference to tbe hydrogen scale by the Central Office ofWeights and Measures at Vienna. The corrections provedso insignificant that it was possible to omit them altogether.Weight of glass and mercury was determined by the maker.h represent

Note About Images