TKANSACTIONS OF SECTION A. 



57 



Dec. 1 : Wanganu). 



Dec. 3: Bull's. 



Dec. 10 : Woodville, Masterton, 

 Wellington, Feildiug, Bull's, Fox- 

 •ton, Wanganui. 



Dec. 15 : Feildiug, Masterton, 

 Wanganui, Foxton. 



Dec. 20 : Feilding, Marten. 



1890. 



Jan. 26: Oamaru (9.50 p.m.), 

 Rotorua (5.54 p.m., 7.22 p.m.). 



Jan, 27 : Rotorua (6 a.m., 8.20 

 p.m.). 



Jan. 29 : Wanganui. 



Jan. 30 : Rotorua. 



Feb. 20: Blenheim, Wanganui, 

 Wellington. 



March 2 : Blenheim, Wellington. 



March 7 : Blenheim, Bull's, Wa- 

 nganui, Napier, Feilding, Taupo, 

 Wellington, Tauranga, Gisborne. 



jMarch 15 : Wanganui. 



IMarch 30 : Cromwell, Queens- 

 town (7.40 p.m., 10.50 p.m.). 



March 31 : Queenstovvn. 



April 7 : Bealey. 



April 10: Wellington. 



May 1 : Queenstown. 



May 5 : Bealey. 



May 6 : Napier. 



June 24 : Bull's, Wanganui. 



June 27 : Riverton. 



July 6 : Blenheim, Rotorua. 



July 16 : Wanganui, Blenheim, 

 Feilding. 



Aug. 15 : Wanganui, Blenheim, 

 Feilding, Wellington, Bull's. 



Aug. 10 : Bealey. 



Aug. 17 : Timaru. 



Aug. 30: Blenheim (3.23 a.m., 

 3.45 a.m.), Welhngton. 



Sept. lG-17 : Wanganui (mid- 

 night). 



Sept. 24 : Wanganui. 



Sept. 25: Bull's, Wanganui (3), 

 Feilding. 



Sept. 29 : Westport. 



Oct. 3 : Wanganui. 



Oct. 4: Rotorua (1.55 a.m., 

 4.33 p.m.), Wanganui (4 a.m.). 



Oct. 5 : Wanganui (2 shocks). 



Nov. 11: Napier, Wanganui. 



Nov. 12 : Grahamstown, Coro- 

 mandel (2 shocks, 5.11 p.m. and 

 5.22 p.m.), Thames, Auckland, 

 Paeroa, Hikutaia, Thames (7 a.m.). 



Nov. 13 : Coromandel (7.15 a.m.). 



Nov. 20 : Gisborne. 



Nov. 23 : Rotorua. 



Nov. 27 : Wanganui. 



Dec. 23: Wellington, Wanganui. 



2. The "Elastic Medium" 2Iethod of treating Electrostatic 



Theorems. 



By Professor W. H. Bragg, M.A., Koyal Society of South 



Australia. 



It is usual to deduce the ordinary theorems of electrostatics 

 from the law that two amounts of electricity repel one another 

 with a force proportional directly to the product of these 

 amounts and inversely to the square of the distance between 

 them. Faraday pointed out that the results so deduced, and 

 confirmed by experiment, could be explained by assuining the 

 existence of an elastic medium, the straining of which was 

 electrification, and the consequent stress electrical force. The 

 elastic constant of such a medium Maxwell proposed to call 

 the " coefficient of electric elasticity." Dr. Lodge has used 

 the idea with the best of results in his book on " Modern 

 Views of Electricity." 



The reading of Dr. Lodge's book suggested to me 

 ;working-out of the results contained in this paper. 





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