170 SEC. 5. MOLECULAR PHYSICS. 



651. Small Barktrometer. Dring and Page. 



The same in principle as the larger one, but it is not capable of indicating 

 over so wide a range of specific gravities. 



652. Salinometer, used on steam vessels to ascertain the 

 amount of salt in the water in the boiler. Dring and Page. 



On the stem of the instrument are the words " limit " and " blow." " Limit " 

 indicates the maximum amount of salt in the water that can be used with 

 safety, and " blow " when it is necessary to blow off a portion of the water iu 

 the boiler through there being too much salt in solution. 



653. Atkins' Saccharometer. (Obsolete.) 



Dring and Fagc. 



654. Tour-weight Hydrometer on Sykes's principle. 

 (Obsolete.) Dring and Fage. 



The stem is divided into 20 parts, and a part again divided into 2 parts, 

 each of which is equal to one-half per cent. The sliding rule accompanying 

 this instrument gives the equivalents of other hydrometers of the same 

 period. About 1817. 



656. Sykes's (Revenue) Hydrometer. For ascertaining 

 the proof-strength of spirits. Dring and Fage. 



The instrument, used by the Kevenue in collecting the duty on spirits, was 

 first established under Act of Parliament in the year 1 8 1 6 ; by this Act also proof 

 spirit (which forms the basis of estimation in this instrument, as all strengths 

 are indicated by their relation to this point) received a particular definition as 

 that which weighed twelve-thirteenths of an equal bulk of distilled water at a 

 temperature of 51 Fah. The stem of the instrument is divided into 10 parts, 

 and each part again into subdivisions, \A hich, with the nine weights (each 

 of which is a multiple of the divisions of the stem), enables the instrument 

 to measure all gravities from 67 over proof to just past distilled water at 

 60 Fah. The tables which accompany this instrument were compiled from 

 ..the experiments of Gilpin, who carried them out with such accuracy that no 

 error has ever been detected. The range of temperature given is from 30 to 

 80 Fah. These tables having been found inconvenient for use in hot climates, 

 in the year 1851, Messrs. Dring and Fage compiled an extension from 80 to 

 100, which meets all requirements for high temperatures. 



657. Clark's Export Hydrometer (obsolete). Used for 

 ascertaining the strength of spirits in the various stages of manu- 

 facture. Dring and Fage. 



The instrument used for determining the strength of spirituous liquors prior 

 to the introduction of Sykes's hydrometer. It was the first of its kind 

 established under Act of Parliament, and to which any definite kind of cor- 

 rection for temperature was applied. It is constructed to show the number of 

 gallons of water, plus or minus, necessary to reduce to proof strength a sample 

 of spirits under trial, and was only used for spirits in the various stages of 

 manufacture. 



658. Clark's Import Hydrometer (obsolete). Formerly 

 used for ascertaining the strength of spirits imported. 



Dring and Fage. 



