38 



ASSOCIATIONS FOR THE ADVANCEMENT OF SCIENCE. (AMERICAN.) 



Elihu Thomson, who is well known for his elec- 

 trical inventions, most of which are controlled 

 by the Thomson-Houston and General Electric 

 Companies. His address was on The Field of 

 Experimental Research. He said in part : " Phys- 

 ical research by experimental methods is both a 

 broadening and a narrowing field. There are 

 many gaps yet to be filled, data to be accumu- 

 lated, measurements to be made with great pre- 

 cision, but the limits within which we must work 

 are becoming at the same time more and more 

 defined. It is but a few months since Prof. 

 Dewar, by the evaporation of liquid hydrogen in 

 a vacuum, closely approached, if he has not 

 reached, our lower limit of possible tempera- 

 ture. We can imagine no limit to possible in- 

 crease of temperature. While we may actually 

 employ in electric furnaces temperatures which, 

 according to Moissan, have a lower limit of 

 3,500 C., we can realize the possibility of tem- 

 peratures existing in the stars measured by tens 

 of thousands or hundreds of thousands of de- 

 grees of our temperature scale. It has been 

 aptly said that many, and perhaps most, of the 

 important discoveries have been made with com- 

 paratively simple and crude apparatus, yet it is 

 probably true also that future advance work is 

 likely to require more and more refined means 

 and greater nicety of construction and adjust- 

 ment of apparatus. In most fields of research, 

 however, progress in the future will depend in 

 an increasing degree upon the possession by the 

 investigator of an appreciation of small details 

 and magnitudes, together with a refined skill in 

 manipulation or construction of apparatus." 

 After reviewing the work on electric waves by 

 Hertz, and the still more recent advances made 

 by Marconi, he said : " Before leaving the con- 

 sideration of this most fruitful field of experi- 

 mental research opened by Hertz, it may be 

 stated that the one gap in the work yet to be 

 filled is the actual production of electric waves 

 of a wave length corresponding to those of the 

 spectrum. Despite the diligent studies which 

 had been made in the invisible rays of the spec- 

 trum, both the ultrared and ultraviolet a work 

 far from completion as yet the peculiar invis- 

 ible radiation of the Crookes tube remained un- 

 known until the work of Lenard and Rontgen 

 brought it to the knowledge of the world. It 

 is needless to recount the steps in the discovery 

 of Rontgen rays. The diffusion which takes place 

 when Rontgen rays pass through various media 

 is another phenomenon which needs more atten- 

 tion from investigators. Again, our knowledge 

 of the aurora is not as yet much more definite 

 or precise than it is in regard to the obscure forms 

 of lightning. Whether these phenomena will ever 

 be brought within the field of research by experi- 

 mental methods is an open question. We de- 

 fine our instruments; we render more trustworthy 

 our means of observation; we extend our range 

 of experimental inquiry, and thus lay the founda- 

 tion for the future work, with the full knowl- 

 edge that, although our researches can not ex- 

 tend beyond certain limits, the field itself is, 

 even within those limits, inexhaustible." 



The following-named papers were read and dis- 

 cussed before the section: Apparatus for the 

 Demonstration of the Varying Currents in the 

 Different Conductors of a Rotary Converter, by 

 Frank C. Caldwell; A New Graphical Method 

 of Constructing the Entropy-temperature Dia- 

 gram from the Indicator Card of a Gas or Oil 

 Engine, by Henry T. Eddy; Compound Harmonic 

 Vibration of a String, by William Hallock; A 

 New Form of Electrical Condenser having a Ca- 



pacity capable of Continuous Adjustment, by 

 Lyman J. Briggs; Time of Perception as a Meas- 

 ure of the Intensity of Light and Relations of 

 Time and Space in Vision, by James McK. Cat- 

 tell ; The Musical Scales of the Arabs and Medi- 

 seval Organ Pipes and their Bearing on the His- 

 tory of the Scale, by Charles K. Wead ; An Abso- 

 lute Determination of the E. M. F. of a Clark 

 Cell, by Henry S. Carhart and Karl E. Guthe; 

 Quantitative Investigation of the Coherer, by 

 Augustus Trowbridge; Polarization and Polariza- 

 tion Capacity, by Karl E. Guthe and Martin 

 D. Atkins; Current and Voltage Curves in the 

 magnetically Blown Arc and in the Aluminum 

 Electrolytic Cell, Some New Apparatus Tachom- 

 eter, Chronograph, Data Collector, Induction 

 Coil, Balance for Standardizing Amperemeters, 

 Standard of Induction, Location of Smokeless 

 Discharge by Means of Colored Screens, Note on 

 the Age of the Earth, and Measurement of Mag- 

 netism in Iron and the Relation between Per- 

 meability and Hysteresis, by Reginald A. Fessen- 

 den; Polarization and Internal Resistance of the 

 Copper Voltameter, by Burton E. Moore; Con- 

 cerning the Fall of Potential at the Anode in a 

 Geissler Tube, by Clarence A. Skinner ; The Equip- 

 ment and Facilities of the Office of United States 

 Standard Weights and Measures for the Verifica- 

 tion of Electrical Standard and Measuring Ap- 

 paratus and An Experimental Test of the Accu- 

 racy of Ohm's Law, by Frank A. Wolff, Jr.; 

 March Weather in the United States, etc., by 

 Oliver L. Fassig; A New Spectrophotometer and 

 a Method of Optically Calibrating the Slit and 

 On Achromatic Polarization in Crystalline Com- 

 binations, by D. B. Brace; A Method for the 

 Study of Phosphorescent Sulphides, by Fred E. 

 Kester; Accidental Double Refraction in Colloids 

 and Crystalloids, by Bruce V. Hill; A Bolometric 

 Study of the Radiation of a Black Body between 

 600 and 1,100 C., by Charles E. Mendenhall; 

 A Bolometric Study of the Radiation of an Abso- 

 lute Black Body, by Frederick A. Saunders; On 

 Thermodynamic Surfaces of P. V. T. for Solid, 

 Liquid, and Gaseous State, by Francis E. Nipher; 

 Optical Calibration of the Slit of a Spectrometer, 

 by E. V. Capps; On Differential Dispersion in 

 Double Refracting Media, by E. J. Rendtorff ; Re- 

 lations of Magnetization to the Modulus of Elas- 

 ticity, by James S. Stevens; On the Escape of 

 Gases from the Planets according to the Kinetic 

 Theory and On Flutings in Kundt's Tube, by S. 

 R. Cook; The Dielectric Strength of Oils and 

 Some Unexpected Errors in Wattmeter Meas- 

 urements, by Thomas Gray; Note on the Prep- 

 aration of Reticles, by David P. Todd ; Electrical 

 Anaesthesia and The Nature of Spoken Vowels, 

 with Reference to the Theories of Helmholtz and 

 Hermann, by Edward W. Scripture ; Pressure and 

 Wave Length, by John F. Mohler; and The At- 

 tenuation of Sound and the Constant of Radia- 

 tion of Air, by A. Wilmer Duff. 



On Aug. 24 a joint session of Sections A and B 

 was held, at which the papers mentioned under 

 Section A were read. 



C. Chemistry. Prof. Frank P. Venable, who 

 fills the chair of Chemistry in the University of 

 North Carolina, Chapel Hill, N. C., presided over 

 this section, and delivered an address on The 

 Definition of the Element. He began by saying 

 that " the conception of an element among the 

 Greek philosophers and the earlier alchemists was 

 very different from the modern idea." Then he 

 followed with a historical outline of the develop- 

 ment of the idea of the element. Closing that 

 portion of his address with : " Thus the elements 

 were recognized as simple bodies because there 



