434 Raporl on IVeights and Measures. 



Weight of a cubic inch of distilled water \\\'\ 



a vacuum at the temp. G2", as opposed \^ , 9'4026430 



to weights in a vacuum also, 252-7'22 ( 



grains . . . . . . . . J 



Consequently a cubic foot 62'3S62 p. Ill •TOSOS'^'' 



avoirdupois . , . . . . • • J ' 



Weight of a cubic inch of distilled vvateri 



in air at ()2" of temperature with a mean vl. 24021S57 



height of the barometer . . 252'45() g'*J 

 Consequently a cubic foot 62-3206 p. avoir. 1. J-7946314 

 And an ounc'eof water l-732()8cubicinches. 1. 0-2387924 

 Culiic inches in the imperial gallon 277*276 1. 2-4429124 

 Diameter of the cylinder containing a 1 . 1-9'39112 



gallon at one inch high .. 18-78933 j 

 Specific gravity of water at different temperatures, that at 62*^ 

 being taken as unity. 



The difference of temperatures between 62^ and 39°, where 

 water attains its greatest density, will vary the bulk of a gallon 

 of water, rather less than the third of a cubic inch. 



And assuming from the mean of numerous estimates the ex- 

 jmnsion of brass 000001044 for each degree of Fahrenheit's 

 rhermometer, the difference of temperatures from 62" to 39° will 

 vary the content of a brass gallon measure just one-fifth of a t-ubie 

 indi. 



It appears that the specific gravity of clear water from the 

 Thames, exceeds that of distilled water at the mean temperature, 

 in the proportion of 1'0006 to 1, making a difference of about 

 one-sixth of a cubic inch, on a gallon. 



Rain water does not differ from distilled water, so as to re- 

 quire any allowance for common purposes. 



LXXXI. A Table of ike Reduction of the Ecliptic to the Equa- 

 tor to every Ten Minutes of the T^07igif.ude of the Points of 

 the Ecliptic. IVilh the Differences, and Variation of the 

 Reduction, for Ten Seconds Variation of the Obliquity, of the 

 Ecliptic J for Jan. 1,.IS01. {Obliquity Ecliptic 28° 27' 57".) 



Argu- 



