DE. EVEEETT OjST THE EIGIDITY OE GLASS. 
145 
correcting factor for T is, as already shown, 1-0183, except for 1(a) (5), for which it is 
1-0119. The correcting factor for F is in every case 1-0159. 
TJncorrected. Corrected. 
T. 
P. 
T. 
E. 
!(«)(&)■ 
543-5 
444-7 
553-4 
451-8 
2 
548-5 
446-0 
558-5 
453-1 
3 (a)(b). 
546-0 
447-5 
556-0 
454-6 
I («)(*)•■ 
552-7 
441-0 
559-3 
448-0 
11(a)(5). 
547-1 
448-5 
557-1 
455-6 
Mean of corrected 
values 
. 556-9 
452-6 
We now proceed to deduce, as in our former paper, the values of t,f, n, M, and k, the 
units being the centimetre and the weight of a gramme. 
For t and f, the torsional and flexural rigidities, we have the expressions 
i= twice distance X force X arm X length x nr 8 - 8 - -r- T, 
f= twice distance X force X arm x length X F, 
where twice distance = 865-4, force =100, arm =55-77, length =23-56. Hence we have 
log f=9-65670— logT=6-91092, 
log/=9-65440-logF = 6-99869. 
The volume of the rod was 10-902, being the loss of weight in water multiplied by 
1*00111, which is the factor proper to the temperature 13-3 F. The length being 23*56, 
we find (putting r for radius of rod) Tf 2 = -46273, r=-38378. 
For Young’s modulus we have 
KQK 
for the rigidity, 
2 1 
n =— 4 =239,020,000; 
nr ’ 5 
for the resistance to compression, 
l = ,=353,264,000; 
3{Sn— M) 
M n 
for Poisson’s ratio. 
<r ==— 1=^—1=^— 1 = -229. 
2 n t F 
The values found last year for another specimen of flint glass, by a different maker 
(see former Paper), were 
M=614,330,000, «=244, 170,000, 
Tc =423,010,000, <r=-258, 
the specific gravity of the present specimen being 2*935, while that of last year’s was 
2-942. 
