474 Geological Society : — 



Table IV.— Formulae for the Correction of the Linear Expansion 

 by Heat of the Alloys. 



Sn 4 Pb L t = L (1 + 10- 4 x 0-2066* + 10~ 6 x 0-0329* 2 ). 



Pb 4 Sn L t = L (1 + 10- 4 x 0-2696*+ 10- 6 X 0-0111* 2 ). 



Cd Pb L, = L (1 + 10- 4 x 0-3002*+10~ 6 x 0-0044* 2 ). 



Sn 4 Zn L,=L (1 + 10~ 4 x 0-2126*+ 10~ 6 x 0-02691* 2 ) . 



Sn 6 Zn L, = L (1 + 10~ 4 X 0-2079*+ 10" 6 x 0-0274* 2 ). 



Bi 44 Sn L t = L (1 + 10~ 4 x 0-1264*+ lO" 6 x 0-0090* 2 ). 



Bi Sn 2 L,= L (1 + 10- 4 x 0-1666*+ 10~ 6 x 0-0034* 2 ). 



Bi 24 Pb L t = L (1 + 10- 4 x 0-1293 + 10" 6 x 0-0073* 2 ). 



BiPb 2 L,=L (l + 10- 4 x 0-2821 + H)- 6 xO-0053* 2 ) 

 Cu + Zn (71 p. c. Cu) L,=L (1 + 10~ 4 x 0-1720*+10- 6 x 0-0086* 2 ). 



Au Sn 2 L, = L (1 + 10- 4 x 0-1315*+ 10" 6 x 0-0096* 2 ). 



Au 2 Sn 7 L,= L (1 + 10- 4 x 0-1388*+ 10" 6 x 0-0088* 2 ). 



AgAu L,=L (l + 10- 4 xO-l722*). 



AgAu L t =L (l + 10- 4 xO-1638*). 



Ag Au 4 L, = L (1 + 10- 4 x 0-1038*+10" 6 x 0-0395* 2 ). 

 Ag+Pt (66-6 p. c. Ag) L,= L (1 + 10" 4 x 0-1415*+ 10~ 6 x 0-0107* 2 ). 

 Au+ Cu (66-6 p. c. Au) L,= L (1 + 10~ 4 x 0-1338*+ 10" 6 x 0-0214* 2 ). 

 Ag+Cu (36-1 p. c. Ag) L,=L (1 + 10~ 4 x 0-1628* + 10- 6 x 0-0182* 2 ). 

 Ag+ Cu (71 -6 p. c. Ag) L, = L (1 + 10~ 4 x 0-1471*+ 10~ 6 x 0-0433* 2 ). 



From the above the following conclusion is drawn — namely, that 

 just as it may be said that the specific gravity of an alloy is approxi- 

 mately equal to the mean specific gravities of the component metals, 

 so also from the foregoing we may deduce that the volume which an 

 alloy will occupy at any temperature between 0° and 100° is approxi- 

 mately equal to the mean of the volumes of the component metals at 

 the same temperature, or, in other words, the cubical or linear coeffi- 

 cients of expansion by heat of an alloy between 0° and 100° are 

 approximately equal to the mean of the cubical or linear coefficients 

 of expansion by heat of the component metals. 



GEOLOGICAL SOCIETY. 



[Continued from p. 234.] 

 November 7, 1866.— Prof. A. C. Ramsay, LL.D., F.R.S., 

 Vice-President, in the Chair. 

 The following communications were read : — 



1. " On some remains of large Dinosaurian Reptiles from the 

 Stormberg Mountains, South Africa. By Prof. T. H. Huxley, 

 F.R.S., V.P.G.S. 



The specimen more particularly described in this paper is a 

 portion of a right femur, 25 1 inches long ; so that the entire femur 

 may be safely assumed to have exceeded 30 inches in length. The 

 peculiar form of the bone, and the characters and position of the 

 trochanters, leave no doubt of the Dinosaurian affinities of the rep- 

 tile to which it belonged, which must have been comparable in 



in the number of the zeros. I have also preferred keeping the exponents con- 

 stant, adding, instead of altering thern, a zero after the decimal point when 

 required. 



