276 DESCRIPTION OF ATKINs's HYDROMETER. 



thofe parts of the vibration to which the maintaining power may 

 be applied fo as to increafe the arc, while the time may be 

 either lengthened or fhortened according to the circumftances, 

 the general nature of the efcapement, &c. and thefe will pro- 

 bably lead to a conclufion, that the corrections of time to be 

 applied to a clock, which either in its arc of vibration or 

 otherwife gives fymptoms of irregularity, can be gained only 

 from direct: obfervation. 



W.N. 



XIII. 



Defcription of Atkins's Hydrometer for qfcertaining the fpecific 

 Gravities of fpirituous Liquors. By J. Fletcher, Efa. 

 Communicated by the Author. 



Utility of de- AMONGST the various papers which are to be found ia 



fcriptionsorphi- . , _ . r . v ' i r • n 



lofophicalin- tne works ot thole journaliits who have fo materially contn- 

 ftrumcnts. buted to the advancement of our knowledge, there are perhaps 



but few which have been more effectually conducive to this 

 end than thofe which are appropriated to the defcription of the 

 internments of fcience. It is indeed much to be lamented, 

 that the merchant, the manufacturer, and the artizan, thou Id 

 continue to be fo generally deprived of the advantages to be 

 obtained from the ufe of fuch of them as are adapted to their 

 purpofes, for want of the necefTary information with regard to 

 the mode of applying them. 



The inftrument which is here intended to be defcribed, is 

 one of thofe which Hand in a great meafure in this predica- 

 ment; and as it appears very well to deferve a defcription, it 

 is conceived that, imperfect as the following one is, it will not 

 be unacceptable. 

 Spec. gr. only It is now univerfally acknowledged, that the fpeciflc gravi- 

 ftren r 'thof fuf- ties of 'P irituous liquors afford the only tolerable criterion of 

 rits. their ftrength, and confequently of their comparative values. 



Toafcertain the fpecific gravity of a liquid with a confiderable 

 degree ofprecifion, is an operation of no great difficulty. The 

 mod accurate method of performing it is perhaps that which is 

 alfo the fimpleft : to weigh the fluid in a veflel in which its 

 bulk is capable of being nicely meafured. Much more, how- 

 ever, 



