Elastic Constants of Quartz Threads. 113 



Observations on the Expansion of Quartz. 



Date 



Weight in 



1 

 Corrected mean 



Vlean temp. 



No. of 



Coefficient of 



cubical 



expansion. 



1889. 



vacuo . 



weight in water. 



of water. 



obs. 





grammes. 



grammes. 



o „ 







Dec. 5. 



2-6971 



1-4897 

 1-4877 

 1-4842 

 1-4776 

 1-4749 

 1-4651 

 1-4897 



71-3 C. 



68-4 

 63-2 

 51-8 

 46-5 

 22-7 

 71-3 





+0-000017 

 +0-000008 

 +0-000032 

 +0-000034 

 -0-000003 



+0-000026 







1-4749 



46-5 







Dec. 13. 



9-1179 



5-0255 



74-08 



6 



+0-000037 







5-0159 



69-85 



5 



+0-000007 







5-0015 



63-59 



8 



+0-0000004 







4-9536 



38-6 



19 



-0-000022 







4-9360 



26-0 



7 









5-0255 



74-08 



6 



+0-000006 







4-9536 



38-6 



19 





Dec. 19. 



14-2170 



7-8703 



83-1 



11 



+0-000004 







7-7027 



29-8 



3 





Dec. 20. 



14-2170 



7-8709 



83-5 



10 



+0-000014 







7-7397 



45-3 



4 



-0-000008 







7-6885 



21-5 



5 









7-8709 



83-5 



10 



+0-000005 





1 



7-6885 



21-5 



5 





Precisely similar experiments on brass left nothing to be 

 desired : in the first set the brass was more or less polished ; 

 in the second it was carefully but lightly gilt. It must be 

 said, however, that here we dealt with a weight of about 73 

 grammes of material, and that consequently with the balance 



Phil. Mag. S. 5. Vol. 30. No. 182. July 1890. I 



