September 12, 1902.] 



SCIENCE. 



419 



ber, would be implied as the chronology 

 of one universe, in which chronology, to 

 its historian, a day is as a thousand years 

 and a thousand years is but a day. The 

 course of the 'flying star,' 61 Cygni, or the 

 inconceivably rapid flight of the runaway 

 star, measuring off two hundred miles each 

 second, as it speeds across our universe and 

 perhaps toward another in the unknown 

 depths of space, when thus viewed, becomes 

 only an incident in the infinitely great. The 

 life and movements of the gnat or of the 

 minutest bacillus afl'ords hardly less attract- 

 ive and impressing studies of the micro- 

 cosm. 



The known and weighed and measured, 

 but never yet seen, companion of Proeyon 

 may yet be found, as has been already the 

 similar companion of Sirius, and, found, 

 may illustrate a phase in the life-history 

 of the worlds as instructive, as impressive, 

 as suggestive, as either of these other phe- 

 nomena of the heavens; but all, near or 

 far, microcosmie or maerocosmic, simple or 

 mysterious and complex, all are but parts 

 of one infinite whole, and there exists, 

 though perhaps never to be fully revealed, 

 a larger science which includes and governs 

 all facts and all natural laws and within 

 which every fact and every law has rela- 

 tions exact, defined and permanent. It 

 is for the scientific investigator to reap, 

 in this unbounded harvest field, just as ex- 

 tensively as his own finite powers give him 

 means and opportunity, leaving to later 

 generations of followers a clean and well- 

 gleaned field as far as he may be permitted 

 to go. 



IX. 



The building of a science is admirably il- 

 lustrated by the work of Rankine and of 

 Clausius, supplemented in details by Kel- 

 vin, Zeuner, Rontgen, Hirm and the later 

 investigators and students of the outlined 

 science. 



Riunford and Davy, Meyer . and Joule, 

 supplied the numerical value of the factor 

 relating the recognized thermal and dynam- 

 ic energies, and the identity of these en- 

 ergies in their essential nature, suspected 

 by the ancients, had been sufficiently proved 

 by the first named. Rankine made his 

 foundation the two principles : 



1. Heat and mechanical energy are inter- 

 convertible and with a definite quantiv- 

 alence. 



2. Any single efliect of the action of 

 thermal energy is proportioned definitely 

 to the quantity of such energy present and 

 acting in the production of the phenome- 

 non. 



Clausius made his fundamental proposi- 

 tions : 



1. The thermal and dynamic energies 

 have a definite and measured quantivalence. 



2. It is impossible for a self-acting ma- 

 chine to derive mechanical energy by trans- 

 fer of heat from a body of lower tempera- 

 ture to one of a higher temperature. 



The latter principle is variously stated 

 by these authors and still differently by 

 others; but the deductions are the same 

 whatever the verbiage. The one principle 

 states the quantivalence of the energies; 

 the other gives a means of determining 

 what amount of energy, under specified 

 conditions, shall be transformed, at the 

 quantivalence stated, from one to another 

 class. The first permits the immediate con- 

 struction of the algebraic expression of the 

 law: 



Such mechanical energy as is transformed 

 in anj^ case has the measure: heat-energy 

 in thermal units multiplied by Joule's 

 equivalent. This is universally recognized 

 as 'the first law of thermodynamics.' 



The second statement leads, directly or 

 indirectly, to the expression of the algebraic 

 relations of work transformed out of heat, 

 or the reverse, to total energy expended in 

 the process studied; the work obtained by 



