290 GRAPE CULTURE AND WINE-MAKING. 



ver cylinder, filled with tliis material up to the division line a ; its 

 conical-shaped neck (i, c) fits so exactly and tightly over the end 

 (S) of the glass tube B, that it can be moved upon it to the divis- 

 ion line Z), and connected in such a manner with the inner hollow 

 of the tube B, that the contents can onhj enter from C into tube 

 B. Fig. 4 shows the cylinder also in full })rofile, as well as a small 

 angular elevator, E. 



I) is a brass cylinder of double sides, having in its upper part 

 a very sensitive thermometer (/). This cylinder fits air-tight and 

 steam-tight over a brass ring soldered to the foot-plate of the part 

 B, and, when the instrument is used, is placed over the upward- 

 tending ring. Its object is to take into its inner hollow the steam 

 rising from the vessel A, and to keep them in connection from all 

 sides with vessel C. 



The space between the double sides serves to prevent the cool- 

 ing off of the vapors that finally find an outlet through two open- 

 ings in the upper part of the inner sides, and escape by means of 

 the tube g. The thermometer / has only 5° of the 100° scale, 

 viz., from 97 to 101, subdivided into ten parts, so that the rising 

 of the quicksilver can be observed to one tenth of a degree. In 

 order to show the manner of experimenting on it, let us make a 

 trial with water. 



We first lift the brass cylinder D, with the thermometer fixed 

 to it, off from the steam boiler, and put it on one side. After this 

 we loosen the part {Fig. 2), and take it off, holding it perpendicu- 

 lar, but without taking the quicksilver cylinder C previously off. 

 Now we put our left hand underneath the foot-plate m, take hold 

 with our right of the quicksilver cylinder C, and turn the whole 

 round in such a manner that the tube-end S (in our drawing point- 

 ed upward) gets a perpendicular downward position. In this we 

 draw the cylinder off from S, and take it into our left hand, hav- 

 ing laid aside part 2. 



C is filled up to a with quicksilver. AVhen used, we fill the 

 space between a and h with the fluid we wish to prove. For this 

 purpose we have the small elevator E {Fig. 4). 



We fill now the boiler A half full of water, and light the lamp 

 (e), and while this boils rearrange the instrument. By degrees 

 steam will evaporate from the water in vessel D. This steam, 

 shut in by the cylinder C^ now presses upon the quicksilver, and 

 pushes gradually so much of it out from it into the tube BB as is 

 necessary to find room for itself. This point is indicated by the 

 division line of the scale. When the quicksilver has attained 

 this, it will not rise any more. A quantity of pure alcoJiol, equal 

 to that of water which we have put into the cylinder, requires a 

 still larger space to expand itself into steam. It drives, conse- 

 quently, the quicksilver higher than the steam of water. 



Upon this power to expand is based the applicability of the 

 vaporimetcr to determine very exactly by per cents., even one 



