at its Maximum Density. 261 



that to the end of which the bulb is attached, lies in an 

 horizontal position, while the longer branch (to which a 

 scale made of ivory and graduated according to Fahren- 

 heit is affixed) projects obliquely upwards and outwards 

 in such a manner that the freezing-point of the scale lies 

 just above the level of the top of the cylindrical vessel 

 in which the cups are placed. 



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

 formed, and in order to close the pores of the cork, it 

 was covered within and without with a thin coating of 

 melted wax, which was polished 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 preserve the 

 regular form of the cup, both within and without. 



The vertical brass tube which supports this cup in 

 the axis of the brass cup is pierced with several small 

 holes, in order to allow the water employed in the ex- 

 periments to pass freely into and through it. 



Having attached about 6 ounces of lead to each of 

 the legs of the brass cup, in order to render it the more 

 steady in its place, it was now introduced with its con- 

 tents into the cylindrical vessel, and the vessel was placed 

 in an earthen basin (E), and surrounded on all sides with 

 pounded ice. This basin was 1 1 inches in diameter at 

 its brim, 7 inches in diameter at the bottom, and 5 inches 

 deep, and was placed on a firm table in a quiet room. 



Several cakes of ice were then placed under the bottom 

 of the brass cup, and the cup was surrounded on all 

 sides by a circular row of other long pieces of ice fixed 

 in a vertical position between the outer walls of the cup 

 and the walls of the cylindrical vessel. These pieces 

 were about 4 inches long, and extended from the bottom 

 of the vessel to within a very short distance of the top. 



