306 Prof. A. W. Pucker on the Density and 



The values of the constants are as follows when x=p — 61 

 (j;>=Epercentage) : — 



a=(K)10957, 

 6 = 0-0001119, 



c = 0-00006458, 

 ^ = 1-1925, 

 m = 0*00011, 



?z= ^6 = 1-348. 



Table 1. 

 (x=p — 61.) 



p- 



(«4-kr)xl0 6 . 



crZ^xlO 6 . 



xio 6 . 



ds/dp 

 (calculated). 



80-54 



13144 



-2014 





11130 



80 '04 



13088 



-1845 





11243 



79-48 



13025 



-1671 





11354 



79-12 



12985 



-1569 





11416 



■ 78-62 



12929 



-1439 





11490 



77-11 



12760 



-1101 



1 



11660 



74-98 



12521 



- 757 



2 



11766 



73-01 



12301 



- 535 



3 



11769 



71-06 



12083 



- 380 



5 



11708 



69-10 



11863 



- 269 



10 



11604 



67-12 



11642 



- 190 



17 



11469 



65-51 



11462 



- 143 



27 



11346 



65-12 



11418 



- 133 



30 



11315 



64-50 



11349 



- 120 



34 



11263 



63-08 



11190 



- 93 



46 



11143 



61-01 



10958 



- 65 



55 



10948 



58-94 



10726 



- 45 



46 



10727 



57-94 



10615 



- 38 



38 



10615 



56-89 



10497 



- 31 



30 



10496 



54-89 



10273 



- 22 



17 



10268 



5291 



10052 



- 15 



10 



10047 



50-91 



9828 



- 11 



5 



9822 



48-91 



9604 



- 8 



3 



9599 



46-94 



9384 



- 5 



2 



9381 



Before comparing these numbers with Mr. Pickering's 

 experimental results it is convenient to deduce from his 

 Table II. the values of ds/dp given by his own smoothed 

 curve. This can be done with fair accuracy for the greater 

 number of points. 



The following Table proves that for a large part of the 

 curve the " second differential " at any point is to within 5 



