ASSOCIATIONS FOR THE ADVANCEMENT OF SCIENCE. 



new field in double-star astronomy. He also 

 gave an account, of the recent investigation upon 

 the dark companion of Zeta Cancri, also of that 

 upon the mass bright ness or cMiulle power by the 

 ton of binary stars, and of some recent investi- 

 gations upon some curious results arising from 

 the fact that the rays of light by which a star is 

 seen require an appreciable interval of time for 

 their propagation through the celestial spaces. 

 This circumstance may be employed in some 

 cases to determine the dimensions of the orbits 

 of the binary stars and their distance from us. 

 In conclusio'n, he directed attention to various 

 new problems presented by the application of 

 the spectroscope to binary stars and to the rela- 

 tion borne by increasing knowledge of these 

 bodies to the formation of a rational cosmogony. 

 The following-named papers were then read 

 and discussed before the section: 



" On Some Attempts to photograph the Solar Corona 

 without an Kdipse," by George E. Hale; "On the 

 Control of the Equatorial Driving Clock," by George 

 \V. Houfh ; "Requisites for governing the Motion of 

 Equatorfal Telescopes," by Worcester R. Warner; 

 u Recent Latitude Determination at the Say re Observ- 

 atory," by Charles L. Doolittle ; " Preliminary Notice 

 -nits of Observations made at Columbia College 

 vatory for Variation of Latitude and Constant 

 of Aberration," by John K. Rees; "A Simple Proof 

 of Radares Symmetrical Form of the Differential 

 Equations of Relative Motion of the Planets," by Or- 

 mond Stone ; " A Configuration of 36 Points, 27 Lines, 

 36 Planes, a Special Case of which lead to Klein's 

 Ily]>crelliptic Configuration of 40 Points, 90 Lines, 40 

 I'huirs," by K. Hastings Moore; "Stellar Photome- 

 try," by Henry M. Parkhurst; "The Crank Curve," 

 by John H. Kinealy ; " An Extension of the Gaussian 

 Potential Theory of Terrestial Magnetism," by Louis 

 A. Bauer; " Slietch of Zone Observations at the 

 Naval Observatory," by Aaron N. Skinner; and 

 "Gil lias's Catalogue of Southern Stars," by Edgar 

 Frisby. 



B. Physics. The presiding officer of this sec- 

 tion was Prof. William A. Rogers, who fills the 

 chair of Astronomy and Physics in Colby Uni- 

 versity, Waterville,' Me. The subject of his ad- 

 dress 'was "Obscure Heat as an Agent in pro- 

 ducing Expansion in Metals under Air Contact." 

 At the outset he said : " Whatever may be said 

 of the advantages offered, either by liquid con- 

 tacts of the metals investigated, or by freedom 

 from exposure to the air in the comparison of 

 standards of length, the fact remains that a use- 

 ful purpose will bo served by a study of the 

 forces tinder which the expansion and contrac- 

 tion of metals take place under the condition in 

 which they are u-ed in every-day experience." 

 Then, after describing the precautions necessary 

 to follow when the two metals are either wholly 

 or partly immersed in water, he proceeded to 

 discuss in detail the methods of investigation 

 that, he pursued on this somewhat obscure sub- 

 ject, giving many tables of figures showing re- 

 sults obtained and the progress made in the re- 

 search. One. phase of his work maybe quoted. 

 He found that " after a mass of metal had re- 

 mained at a nearly constant temperature for a 

 considerable time, the inertia, which must be 

 overcome by any change of temperature before 

 a variation in molecular action takes place, 

 seems to be much greater than after harmonic 

 molecular action had begun." In other words,' 

 "the inertia ol comparative molecular rest is 



much greater than the inertia of established 

 molecular motion." He referred to the exist- 

 ence of varying thermal forces which seem to 

 govern the process of cooling, and suggested 

 that this ought to furnish an explanation of the 

 periodic variations in the readings of thermome- 

 ters when the comparisons are made at regular 

 intervals of time. The discussion of the results 

 will be deferred until a future occasion, but in 

 the meantime additional observations will be 

 made especially with improved appliances, the 

 construction of which has been suggested by the 

 work already accomplished. 



The folloVing-named papers were read and 

 discussed before the section : 



" A Problem in Stereoscopic Perspective," by W. 

 Le Conte Stevens; " On the Directed Velocity of the 

 Particles in the Electric Arc," by Benjamin W. Snow ; 

 " Aluminum Violins," by Alfred Springer ; " The 

 Photography of Manometric Flames not yet decided," 

 by William Hallock ; " A New Form of Spectropho- 

 tometer," by Edward L. Nichols ; " The Thermal Con- 

 ductivity of Cast Iron," by I. Thornton Osmond; 

 " Thermal Conductivity of Copper at Low Tempera- 

 ture." by Robert W. Quick and B. S. Lanphear ; " The 

 Influence of Heat and Electricity upon \ oung's Mod- 

 ulus for a Piano Wire," by Mary C. Noyer ; " The 

 Influence of Temperature upon the Transparency of 

 Solutions," by Edward L. Nichols and Mary C. 

 Spencer; " Studies of the Lime Light," by Edward 

 L. Nichols and Mary L. Crehore : " A Calorific Effect 

 of the Velocity of Migration of Hydrogen Ions," by 

 Samuel Sheldon ; " On the Radiation of Obscure 

 Heat by a Metallic Bar," by Benjamin W. Snow ; 

 " The Infra-red Spectra of Metals," by E. P. Lewis 

 and Ervin S. Ferry; "On Magnetic Potential," by 

 Frederick Bedell ; " On Electric Strength," by George 

 W. Pierce ; " A Phonographic Method for recording 

 the Alternating Current Curve," by C. J. Rolleson ; 

 " On the Solution-Tension of Metals," by Harry C. 

 Jones ; " A New Recording Thermometer for Closed 

 Spaces," by William H. Bristol : " On Some Magnetic 

 Characteristics of Iridium," by Solomon H. Brackett: 

 "Lighting as a Case of the Dissipation of Energy,'' 

 by N. D. C. Hodges; "Some Peculiar Lightning 

 Flashes," by Alexander McAdie; "The Attributes of 

 Matter" and "Definition of Motion," by John W. 

 Powell ; and " Device for Comparing Natural with 

 Tempered Musical Scales," by Morris Loeb. 



C. Chemistry. Prof. Thomas H. Norton, who 

 fills the chair of Chemistry in the University of 

 Cincinnati, in Cincinnati, Ohio, chose as the sub- 

 ject, of his address, " The Battle with Fire," in 

 which, differing with his predecessors, who have 

 discussed subjects in pure science, he presented 

 a matter which had to do with certain economic 

 aspects of chemistry. He began by pointing out 

 that of $200,000,000 representing' the total an- 

 nual loss of insured property by fire, nearly one 

 half, or $90,344,075, occurs in the United States. 

 Our total loss of property by fire amounts to one 

 fifth of the. net profits of all the industries of the 

 country. In the matter of protection against 

 loss by fire there are two distinct lines of action : 

 prevention and cure, or the adoption of such 

 measures as to render an outbreak of fire diffi- 

 cult and a conflagration practically impossible, 

 and provision of the proper facilities' for the rapid 

 subjugation and limitation of a fire under full 

 headway. Under the head of fire extinguishers, 

 such agents as carbon dioxide, sulphur dioxide, 

 chemical engines of various kinds, including such 

 as the well-known forms of Babcock. Harkness, 

 and Climax extinguishers and hand grenades. 



