572 



SCIENCE 



[N. S. Vol. XXV. No. 641 



Of the 88 separate residuals three quar- 

 ters are less than 0^01 each, a quantity 

 that I had supposed less than the uncer- 

 tainty with which a clock comparison was 

 read from the chronograph sheet. 



At the end of October, 1906, the 6-ineh 

 transit circle was equipped with a self- 

 registering right ascension micrometer of 

 the Repsold type made by Warner and 

 Swasey. 



Previous to beginning the following 

 series of observations, one of the observers 

 had practised with the new micrometer on 

 two nights and the other two on one night 

 each. Two men worked on each of the. 

 eight nights, each observing ten time stars. 

 Each man on half of the nights that he 

 worked observed the first list of ten stars, 

 and on the remaining nights the second list. 

 The same twenty stars were used through- 

 out the entire series. 



A least-square solution gives for relative 

 personal equation 



and 



E — F = + O'.OOl ± 0'.012 



-i = — O'.OOl ± O'.OIS. 



The relative personal equation E —L by 

 the key method of observing was + 0^20. 



The clock rates during these six weeks 

 were also comp^^ted by least squares, first 

 giving a weight unity to each rate and, 

 second, a weight equal to the interval be- 

 tween the observations from which it was 

 determined. 



The resulting rates are 



and 



-0'.0436-l- 0.000924 (T — Nov. 25.0) 

 -0».0445 + 0.000997 (r — Nov. 25.0), 



giving as residuals: 



A similar discussion of rates obtained 

 by the key method of observing transits 

 gave for thirteen weeks in the spring of 

 1904 a mean residual of 0°.015. 



We thus see that by the use of the self- 

 registering right ascension micrometer in 

 this series of observations the mean residual 

 of the daily clock corrections is decreased 

 from 25 to 50 per cent, and relative per- 

 sonal equation has disappeared. 



Harold Jacoby, 

 For the Co^mcil 

 (To le concluded) 



TEE AMERICAN ASSOCIATION FOR THE 



ADVANCEMENT OF SCIENCE 



SECTION I— SOCIAL AND ECONOMIC 



SCIENCE 



Fifteen different papers and addresses 

 were presented at the New York session. 

 The attendance varied from thirty-five to 

 over a hundred persons. One joint session 

 with Section H was held. In the absence 

 of Professor Irving Fisher, whose address 

 has already appeared in Science, at the 

 opening session, the incoming vice-presi- 

 dent for the section, Charles A. Conant, 

 presided, beginning the proceedings with 

 an introductory discussion on banking re- 

 form, the substance of which was as fol- 

 lows: 



Unless some sound legislation is in due 

 time enacted, our prosperity will be ar- 

 rested, our rapidly absorbed currency will 

 prove entirely inadequate for business 

 needs, and we must be put at a great dis- 

 advantage at home and in our competition 

 with foreign nations in the open markets 

 of the world. 



The proposed banknote reform, it should 

 be understood, is not a measure intended 



