ASSOCIATIONS FOR ADVANCEMENT OF SCIENCE. (AMERICAN.) 



from its greatest brilliancy until it becomes in- 

 visible to the eye for several months, then reap- 

 .MI I gradually recovers its original brill- 



iancy'; and then from this first variable star he 

 gave the history of other discoveries of similar 

 Indies. Concerning the numerical distribution 

 of the variabli-s with reference to the time oc- 

 cupied in completing a single cycle of their 



. he said that it ranges from the short 

 period of Lew than eight hours to about two years. 

 - the distinctly periodical stars, Prof. 

 Chandler told about a considerable number in 

 which there is no discernible law or regularity, 

 and also an intermediate group in which this 

 appears in a very weak degree. One or two 

 there are which remain steady during long inter- 

 vals of time, then begin, without warning, a 

 series of astonishing and apparently lawless 



. and later become again quiescent. The 

 following papers were read before the section: 

 Double Star Observations," by George W. 

 Hough ; "Application of the Method of the Logi- 

 cal Spectrum to Boole's Problem," by Alexander 

 Macfarlane; " Some Personal Experiences on the 

 K x ped i t id 1 1 1 o Cayenne, French Guiana, to observe 

 tin- Krlipse i if Dec. 22, 1889," by Charles H. Rock- 

 well : -The Problem, to circumscribe about a 

 Conic Triangle which shall be inscribed in a Tri- 

 angle which is itself inscribed in the Conic, and a 

 Certain Question concerning two Binary Cubes," 

 by Kliakim H. Moore; "A Method for testing 

 I'rimes," byJamesD. Warner; and "A Theorem 

 of Plane C'ubics," by Frank H. Loud. During 

 the session at Terre Haute, on Aug. 22, Section A 

 met with Section B. 



\>. I'hysics. Cleveland Abbe, of the United 

 States Signal Service, presided over this section. 

 His address was a plea that the principles of 

 molecular physics and chemistry might be ap- 

 plied to the study of the earth as a unit as well 

 as the principles of mathematics and astronomy. 

 He included the subject of terrestrial physics un- 

 der the term geo-physics, dividing this again in- 

 to geognosy, I he study of the entire phenomena of 

 the earth's crust ; vulcanology, or the study of the 

 interior of the earth as related to heat and con- 

 tract ion; seismology, or the study of earth- 

 quakes and the allied phenomena of faulting 

 and mountain forming; gravitation phenomena 

 ami its variations as related to latitude and alti- 

 tude ; the relations of the land and water areas ; 

 and, la.st.ly, the total of knowledge comprised un- 

 der meteorology. |,.,,[ Abbe closed his address 

 with an urgent appeal for a laboratory in which 

 to con>ider these topics. "America has no in- 

 stitution for the largerand profounder secretsof 

 the globe. We should 'go into the land and pos- 

 MH it' in i he largest sense, so that year by year we 

 may < ..me nearer to eternal truth." The follow- 

 ing-named papers were presented : 



" Magnetic and Gravity Observations on the West 

 Africa and at Some Islands in the North and 

 s,,,itl, Atlantic," i.\ K. I). Preston; "On the Use of 

 the MaffnetOffraph as a Seumosogpe." by Thomas 

 '. Mendenhall; ''Exhibition of Seismograph," by 

 TbomM i ir.-iy ; " The Effects of the Atmosphere and 

 Oceans on the Secular Cooling of the Earth/' by Rob- 

 ert S. Woodward; "Description of the Equal-Tem- 

 perature Room in the Observatory and Physical Lab- 

 onit-.ry of Colby University" and " Is Thermomctry 

 an Exact Bdenoef," by William A. Rogers; " De- 

 termination <>f the Tension of the Vapor of Mercury 



at Ordinary Temperatures," by Edward W. Morley ; 

 " New Metric Standards," by Thomas 0. Menden- 

 hall ; " Exhibition of a Combined Metre with Subdi- 

 visions to 2 mm. and a Yard subdivided to Tenths of 

 Inches, both being Standards at 62," by William A. 

 Rogers ; " Exhibition of Verns's Photographs in Nat- 

 ural Colors," by Orry T. Sherman; "Report on the 

 Velocity of Light in a Magnetic Field," by Edward 

 W. Morley and Henry T. Eddy ; " Radiation at a 

 Red Heat (A Preliminary Note on the Radiation from 

 Zinc Oxide)," by Edward L. Nichols and Benjamin 

 W. Snow ; " Exhibition of Plans and Sketch of the 

 New Physical Laboratory, ' Wilson Hall,' of Brown 

 University, Providence, R. I.," by Eli W. Blake. 

 " Aberration Methods of Determining the Altitudes 

 and Motions of the Clouds," by Cleveland Abbe; 

 " A New Self-regulating Photometer," " Recent 

 Studies in the Ultra-violet Spectrum," "The Great 

 Lick Spectroscope," and "Recent Photographs of the 

 Moon by Direct Enlargement," by John A. Brash- 

 ear ; " Further Study of the Solar Corona " and " Ter- 

 restrial Magnetism," by_ Frank H. Bigelow ; " Method 

 of Measuring the Electrical Resistance of Liquids," by 

 Francis E. Nipher ; " Ampere-metre for Feeble Alter- 

 nating Currents : The Farado-Metre,"_ by Wellington 

 Adams; "Note on Certain Peculiarities in the Be- 

 havior of a Galvanometer when used with a Thermo- 

 pile " by Ernest Merritt ; " History of Wilson Hall," 

 by Eli W. Blake ; " Prediction of Cold Waves from 

 Signal Service Weather Maps," by Thomas Russell; 

 " Surface Integrals in Meteorology," by Francis E. 

 Nipher ; " The Marine Nephoscope," oy Cleveland 

 Abbe ; " On Certain Electric Phenomena in Geissler 

 Tubes," by H. S. Rodgers and Thomas French, Jr. ; 

 " Magnetic and Electric Phenomena viewed as a Man- 

 ifestation of Strain," by W. F. Durand ; " Electrical 

 Oscillations in Air," by John Trowbridge and Wal- 

 lace C. Sabin ; " On Maximum Temperatures," by 

 Amos E. Dolbear ; " The Specific Inductive Capacity 

 of Electrolytes," by Edward B. Rosa ; " Discussion 

 of the Formulas indicating the Work of an Electric 

 Motor," by George W. Hough ; " Experimental De- 

 termination of the Time acquired for Water to pass 

 from 42 to 72 in a Constant Air Temperature," by 

 William A. Rogers ; " Plan for a Resistance Box," by 

 Albert L. Arey ; " On the Specific Heat of Brine near ' 

 Fahr.," by James E. Denton ; " Experimental De- 

 termination of the Rate of Change in Underground 

 Temperatures at a Depth of Nine Feet bv Means of a 

 Flow of Water at a Constant Level," by William A. 

 Rogers ; " Observations taken in Four Balloon As- 

 cents," by W. H. Hammon; "On a Form of Pneu- 

 matic Commutator 'and its Use in the Automatic Op- 

 eration of Physical Apparatus," by David P. Todd ; 

 " On the Phosphoric Lamp," by F. W. Very ; " On 

 the Advisability of applying the C. G. S. System of 

 Modern Electricians to the 'Principles of Elementary 

 Mechanics," by P. H. Van der Weyde ; "Flow and 

 Friction of Fluids in Open Channels," by D. T. 

 Smith ; " Evaporation as a Distributing Agent in a 

 Determination of the Temperature of Water," by 

 William A. Rogers ; " Some Results of Observations 

 made during the Recent United States Scientific Ex- 

 pedition to the West Coast of Africa," by Cleveland 

 Abbe ; " Earthquake and Volcanic Action in Japan " 

 and " A New Transmission Dynamometer," by 

 Thomas Gray ; " Actinic Action of Electric Dis- 

 charge," by Thomas French, Jr. ; " Is Chemical Ac- 

 tion influenced by Magnetism," by Morris Loeb; 

 " Index to the Literature of Thermo-dynamics," by 

 Alfred Tuckerman; and " Description of a Series of 

 Tests for ihe Detection and Determination of Subnor- 

 mal Color Perception ; designed for Use in Railroad 

 Service," by Charles A. Oliver. 



C. Chemistry. This section was presided over 

 by Robert B. Warder, of Howard University, 

 who presented an address on " Recent Theories 

 of Geometrical Isomerism," of which the chief 

 aim was " to present a theory which might serve 



