280 DESCRIPTION OF ATKINs's HYDROMETER. 



on that part of the Aider oppofite to the thermometrical fcale 

 D, is to be fet to the degree of temperature fo found, and the 



Divifion on Aider divifion on the line C, marked "Atkins," which then corref- 



•nfwering to the ds Qn e j ther flde of the ru j e w ; t h t hat letter and divifion on 



letter on the ftera r 



gives perccn- the alphabet line A, at which the flem was cut by the furface 



t3 8 e * of the liquor, indicates the ftrength and value in commercial 



Example from terms. Thus fuppofe the temperature to be 68° (at which the 

 the plate." * * nc *ex appears fet in the plate), and the hydrometer, when 

 loaded with its weight No. 1, to float with the furface, cutting 

 the divifion I on the flem (correfponding to a fpecific gravity 

 of about 854f ), we find, on fetting the Aider of the rule to 68° 

 on the thermometer fcale, that 46 over proof correfponds to 

 that letter and divifion, and is confequently the ftrength and 

 value of the liquor. 

 Ufes of the other The lines marked " Dicas" and " Clark" on the rule, are 

 flScr 00 e ^ or £* vm S * ne appreciation of the values and ftrengths as (hewn 

 by the inftruments invented by thofe artifts, and are intended 

 for the ufe of fuch as have been in the habit of employing 

 them ; the latter being perhaps inferted principally on account 

 of the ufe of Clark's inftrument for the purpofes of the re- 

 venue. 

 Of the concen- The figures on the line marked " concentration" amongfl 

 tration-line. ^ e over .p roo f Sf indicate the diminution in volume which takes 

 place on reducing the given compound to proof; and amongft. 

 the under-proofs, the diminution which takes place on reducing 

 Concentration proof-fpirit to that ftrength. This raufl in the firft cafe be de- 

 to be deduced rfu&ed f rom the quantity marked on Atkins's line (C), in order 

 from the per , i- . «» 



centage. to obtain tne accurate per centage according to the eftimation 



Example. Di- of commercial men. For infiance, 50 over-proof on Atkins's 



roinut on of 3 line indicates, that if to 100 parts of fpirit of the ftrength which 



Soofwate^to 5 anfwers to this divifion, we add 50 of water, we (hall get 



iooof5oover- proof-fpirit, of which, however, the quantity will be only 147 



proof ' parts ; the concentration or diminution of bulk by mixture be- 



Concentration ing 3 parts. With regard to the fpirit which is under-proof, 



on mixture of ^e flor Ur es on the concentration line indicate the diminution of 

 pr •">f-ipiric and ....'* , nn 11 /• ,i • , -r r 



water. volume 10 pints for every 100 gallons ot the mixture: it, for 



inftance, 70 gallons of proof-fpirit be combined with 30 of 

 water, we get a compound whofe ftrength is that which is 

 marked on the line C, 30 under proof; but the concentration 

 being feven pints, we (hall get only 99} gallons. 



4 When 



