5*^ EFFECrs OF CLOTHING, &i.C» 



XII. 



An Enquiry concerning the Nature of Heat and the Modes of its 

 Communication, By Benjamin Count of Ruwford, 

 V. P. R. S. Sfc. Abridged from the Philofophical Tranf 

 actions for the Year 1 804-. 



Expcrimcntson x\FTER remarking that all difcovcries on an agent of fuch 

 ^ extended operation as heat cannot fail to be eminently ufeful, 



the author proceeds to defcribe the apparatus ufed in the ex- 

 periments now to be defcribed : They were the following. 

 Inftramcnts. I. Mercurial thermometers carefully conftrufled, having 



Thermometers, cylindrical bulbs, four inches long and four tenths of an inch in 

 diameter, and their tubes from 15 to 16 inches long; the air 

 being excluded, and the graduations according to Fahrenheit, 

 exhibiting eight parts of degrees by means of a nonius. 

 Inffmments. 2. Four cylindrical veflTels of thin (heetbrafs, for afcertaining 



Cylinders to the warmth of clothing. Fig. I. Plate I. The veflel isclofed 

 water and fuf- ^t both ends; but has a neck at the top, into which hot water 

 fcred to cool with js occafionally poured, and in which one of the thermometers 

 ol' cloSiing. ^^ fitted and placed during the time of an experiment, fo that 

 its long bulb ftiall occupy the axis of the velFel, and will (liew 

 its mean temperature. Another cylindrical neck proceeds from 

 the lower furface, and is lilted upon the adjuftable part of the 

 wooden ftem beneath. The vefiels are four inches long and 

 four inches diameter, and the necks are about eight tenths of 

 an inch in diameter, the upper one being four inches long and 

 the lower three inches. When the vefTel is clothed and charged 

 with hot water, its rate of cooling by expofure to the quiet air 

 of a large room, will fhew the relative warmth of each parti- 

 cular kind of clothing. 



In fome of the experiments the ends of the inftrument were 

 permanently covered by the application of a thin wooden box 

 to each, the box being varniflied and covered with fine writing 

 paper, and filled with line eider down, and a cap of fur was 

 pulled over the box, and the projeding neck. The cloth- 

 ing of thefe cafes was applied for experiments to the cylindrical 

 furface. 



Twoof the inftruraents (No. 1 and 2.) were thus covered 

 up at the ends, and the other two (No. 3 and 4) were left in 

 the flate reprcfented Fig, 1 . without the permanent coverings* 



In 



