THE FIELD OF EXPERIMENTAL RESEARCH. 121 



temperature passing all present known limits and capable of effecting 

 profound changes in molecular constitution. We need all possible 

 extension of the limits of research in this direction in order to discover 

 some clew to the relations which the chemical elements bear to each 

 other. The limit of possible strength of the containing receptacle, or 

 some unforeseen factor, would probably set the new bounds. The 

 point to be here enforced, however, is that far beyond any increase of 

 Avorking range in temperature, obtained in any way.^ there must still 

 exist a further range unattainable by our best efforts and possibly for- 

 ever outside of the field of experimental research. Our knowledge of 

 this higher range can alone be derived from a study of the actions 

 going on in the stars and nebulse. 



As with the temperature range, so it is with the pressure range. We 

 may easily work under conditions which involve no pressure, but when 

 we attempt to conduct our inquiries with increase of pressure we soon 

 find a limit to the tenacity of our strongest vessels or to our ability to 

 produce and maintain extreme pressures. We may work, not easily 

 it is true, with pressures up to a few tons to the square inch, but this 

 is as nothing compared to the conditions which we know must exist 

 within the larger celestial bodies, without reference to their condition — 

 solid, liquid, or gaseous. Can we ever hope to experimentally repro- 

 duce the condition of a mass of gas so compressed that in spite of a 

 very high temperature its volume is less than that of the same mass 

 cooled to solidification? Yet this extreme of condition must be the 

 normal state within the bodies of many^ of the stars. 



It has been aptly said that many and perhaps most of the important 

 discoveries have been made with comparatively simple and crude 

 apparatus. While this maj^ be true, 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 adjustment of apparatus. The 

 expense or cost, if not the difficulty of the work, may become so great 

 as to effectually ]>ar further progress in some fields. When instru- 

 ments reqviire to be adjusted or constructed to such refined limits as 

 a fraction of a wave length of light, but few can be found to undertake 

 the work. The interferometer and echelon spectroscope of Michelson 

 involve such minute adjustments that a wave length of light is rela- 

 tively thereto a large measure. It is well known that this comparative 

 coarseness of light waves imposes a limit to the powers of optical 

 instruments, as the microscope and telescope, such that no perfection 

 of proportion, construction, and correction of the lenses can remove. 



In most fields of research, however, progress in the future will 

 depend in an increasing degree upon the possession, by the investiga- 

 tor, of an appreciation of small details and magnitudes, together with 

 a refined skill in manipulation or construction of apparatus. He nuist 

 be ready to guide the t"a-ue 1 mechanic and be able himself to admin- 



