May 6, 1904.] 



SCIENCE. 



735 



3. The fact that natural albite (Mitchell 

 Co., N. C, Amelia Co., Va.) is too low in melt- 

 ing point and too high in specific gravity to 

 fall into line with the observations upon the 

 pure feldspars is readily explained by the im- 

 purities established by the chemical analyses. 



4. The curve of specific gravities of the arti- 

 ficial crystalline feldspars which admit of ex- 

 ceptionally accurate observation, on account 

 of the chemical purity of the specimens, is also 

 a straight line over practically the same range. 



5. No natural feldspar is known with a lower 

 specific gi'avity than albite. 



The following preliminary figures were 



given : 



Mpltine Specific Specific 



p^i^?5 Gravity Gravity 



romts. (Crystals). (Glass). 



An 1532° C. 2.764 2.70 



AbiAn, 1503° 2.736 2.65 



AbiAnj 1464° 2.702 2.60 



AbiAni 1420° 2.670 2.55 



AbjAiii 1374° 2.48 



AbjAiii ..about 1345° 2.46 



Ab 2.38 



Alfred H. Brooks, 



Secretary. 



THE PHILOSOPHICAL SOCIETY OP WASHINGTON. 



The 583d meeting was held March 26, 1904. 

 The election of twelve new members was an- 

 nounced. 



Mr. L. A. Bauer reported that magnetom- 

 eter records showed slight earthquake shocks 

 on March 16 and 21. 



Mr. Bergen Davis, of Columbia College, 

 spoke on ' The Theory of the Electrodeless 

 Discharge.' A receiver containing gas is 

 placed in the field of a coil through which an 

 alternating current passes; when the field 

 reaches a certain miniraum potential there is 

 a white discharge through the gas; this po- 

 tential was determined as a function of the 

 gas density and alternation-frequency. The 

 results were found to be in close accordance 

 with the theory of electrons. 



Mr. P. G. Nutting then spoke on ' The 

 Dynamics of a Moving Charge,' presenting 

 systematically the dynamical principles that 

 underlie the theory of electrons, and pointing 

 out among other things the great differences 



in the nature of the fields produced by elec- 

 trical charges moving at different velocities. 



The 584th meeting was held April 9, 1904, 

 Vice-president Littlehales presiding. 



Dr. Bauer reported that the earthquake 

 shock of March 16 was recorded by the mag- 

 netograph at Baldwin, Kansas; such records 

 have now been found made on about thirty 

 different dates. 



Dr. E. A. Harris, of the Coast and Geodetic 

 Survey, presented a paper on ' Some Indica- 

 tions of Land in the Vicinity of the North 

 Pole.' 



The indications of land were based chiefly 

 upon (1) the direction and velocity of the 

 surface currents, known, in part, by the drift- 

 ing of the Advance and Rescue, the Jeannette 

 and the Fram; (2) the very old ice found 

 northeast of Alaska; (3) the tides at Bennett 

 Island, at Pitlekaj, along the northern coast 

 of Alaska, and in the Arctic Archipelago. 

 At Bennett Island the mean range of tide is 

 2 feet ; at Pitlekaj, 0.2 foot ; at Point Barrow, 

 0.4 foot, the fiood there coming from the west. 



The main conclusion arrived at was that a 

 large trapezoidal tract of land may extend 

 from near the North Pole towards Alaska and 

 eastern Siberia — one corner lying nearly north 

 of Bennett Island; another, a little west of 

 north from Point Barrow; a third, a com- 

 paratively short distance northwest of Banks 

 Land; and a fourth corner, north of Lincoln 

 Sea. 



The observations of Thomas Simpson show 

 a remarkable change in the time of tide on 

 the northern coast of Alaska near the eastern 

 boundary. This seems to indicate that one 

 or more islands probably lie not very far off 

 to the northward of this locality. 



The subject was further discussed by Dr. 

 Dall. 



Mr. George R. Stetson then read a paper on 

 ' President Stiles and his Times, Yale, 17Y8- 

 1795,' based on the recently published vol- 

 uminous diaries. These were summarized, 

 presenting a vivid picture of the political, in- 

 tellectual, social and religious conditions of 

 the times. Ohaeles K. Wead, 



Secretary. 



