218 SIMMERING OF WATER. 



Singular noife of of the waler-liammer, is that of agitating its contents. The 



^^^\'^'^'^^^*''^ ""remarkable effea it exhibits is, that the parts of the water 



firike againft the glafs and agaiiifi: each other, with the (liarp 



Another experi- noife ufually produced by the collifion of hard bodies. Another 



produced and experiment, which I alluded to, is tliat, if. the ball be held 



condenfed ^ downwards fo as to become filled with the water, and it be 



fecond '""*^*"^^*^®" (lowly railed up^ fo as to bring the tube nearer to the 



horizontal pofition, the heal of the hand which holds the 



tube will produce vapour or fieani ftrong enough to prevent 



the fluid from running down to its level from the upper fur^ 



face of the globe ; but a little farther inclination caufes it to 



defcend, and a bubble of the fleam enters the globe itlelf 



and afcends through the fluid. But it fcarcely arrives at the 



o lop before it is condenfed, and the water collapfes with a 



fmart ftroke or noife, fo as to fill the globe again. The fuc». 



jceirion of ihefe bubbles and their condenfalion take place 



fo rapidly, in a well made inltrument, that ten or twelve 



applied toexplaincollapfions occur in every fecond of time. The faft, and the 



the cfte€t ot obvious remarks 1 made upon it, convinced my friend that I 

 fimmennjr. , • ' •' 



had (uggefted the proper explanation. 



Objeftions. It was my intention however to have healed fome water 



in a veflel irt order to obferye and afcertain the progreffive 

 appearances, but 1 had not done it when I ^gain had the 

 pleafure to meet this intelligent obferver, fje complimented 

 me upon the ing,enaity of my folution, but having himleU 

 fince repeated the experiment of boiling water, it feemed 

 from his report that ingenuity was qll the value it could claim. 

 '* Take a bright tin velfeT' faid he ** and heat water in it; 

 you will hear the noife, but no bubbles are to be Teen.'' 



I took ijie earliefi opportunity of making fome experinienl?, 

 the particulars and refults of which are as follow : 



Exp. 1. Water Exp. 1, A fmall glafs retort, the body of which is about 



was heated in a ^^^^ inches in its fliortefi or horizontal diameter, was fufpended 

 glafs retort. The . ' , ' 



fimmering was fo that its neck was elevated about twenty degrees above the 



attended with level. Water was then poured in to fill the body and the 

 fteam bubbles. _ -, it.,- ■ ^,,- . i 



greateft part oi the neck. My mtention m liUmg the neck 



was, that I might be able to obfirve whether any greater or 



more fudden rife took place before the period of boiling than 



the well known expanfion of the fluid. A fmall fpirit-lamp 



was placed beneath the bulb. The coldnefs of the water in 



the veflel immediately condenfed a portion of the water whi(,h 



iil'ued 



3 



