MAXtMtTM DENSltY Ot WATEH. . 2^7 



On one fide of this cork cup there is a fmall opening, which having in its 



• . .. , . /> . 1 1 \ -^ c*i center die bu.b of 



receives, and in which is confined the lower extremity or the 



tube of a fraall mercurial thermometer, (D). The bulb of • 

 this thermometer, which is fpherical, is juft -j^e ^^ ^" '"^^^ "^ 

 diameter, and it is fo fixed in the middle of the cup, that its 

 centre is juft | of an inch above the bottom of the cup ; con- 

 fequently it does not touch the cup any where, nor does any 

 part of it projefl above the level of its brim. 



The tube of this thermometer, which is fix inches in length, a thermometer, 

 has an elbow near its lower end, at the diftance of one inch 

 from its bulb, which elbow forms an angle of about 1 10 

 degrees, and the thermometer is fo fixed in the cup, that the 

 iliort branch of its tube, namely, that to the end of which 

 the bulb is attached, lies in an horizontal pofition, while the 

 longer branch (to which a fcale, made of ivory, andgraduated 

 according to Fahrenheit is affixed,) proje^s obliquely upwards 

 and outwards, in fuch a manner that the freezing point of the 

 fcale lies juft above the level of the top of the cylindrical 

 veflel in which the cups are placed. 



The cork cup, which was turned in the lathe, is neatly Other partlcu- 

 formed, and in order, to clofe the pores of the cork, it was '^"» 

 covered, within and without, with a thin coating of melted 

 wax ; which was polifiied after the wax was cold. 



The thermometer was fixed to the cork cup by means of 

 wax, and in doing this, care was taken to preferve the regular 

 form of the cup, both within and without. 



The vertical brafs tube which fupports this cup in the axis 

 of the brafs cup, is pierced with many holes, in order to 

 allow a free paffage into it, and through its fides, to the 

 water employed in the experiments. 



Having attached about fix ounces of lead to each of the This apparatus 

 legs of the brafs cup, in order to render it the more fteady in pan, and fur- 

 its place, it was now introduced with its contents, into the rounded with 

 cylindrical veflel, and the velfel was placed in an earthen "^' 

 bafin (E) feven inches in diameter below, 1 1 inches in dia- 

 meter at its brim, and five inches deep, and was furrounded 

 on all fides with pounded ice. 



Several flat cakes of folid ice were now put into the cy- Ice was placed 

 lindrical veflel, and faftened down upon its bottom, and utider the c M^rrdncal 

 the bottom of the brafs cup, and a circular row of other long veffei; bu^ not 

 pieces of ice were placed^ in a vertical pofition, round the ^" ,''?^ ^^?^» 



Q 2 outfide water was powed 



