312 TRANSACTIONS OF THE CANADIAN INSTITUTE. [V on. UNG 
nomical details which stand in clear relationship with the outer world in which almost 
daily conflicts come to the surface between the different designations of dates. Con- 
flicts among others which are even injurious to astronomical labours in such observa- 
tories where observations are continually adjusted to the day. . . . While the 
I)irectors of the Pulkowa Observatory make their full acknowledgment to the Astro- 
nomer Royal for this precedent, which has been established, so are they ready to follow 
the example, and this fact leads us the more to expect that also this course will be 
adopted by the Washington Naval Observatory, as in the American Marine the Date 
Notation from midnight has been already accepted. It is only in the matter of the 
period when the Date Notation, according to Universal Time, should be introduced 
into the publications of the observatories, that we feel inclined to recommend that 
there should be delay until, in this respect, the most perfect possible understanding be 
attained by all astronomers, in order to avoid the much more critical disturbance in 
astronomical chronology which would arise if the transition to the new Date Notation 
was not equally followed on all sides. We are desirous, accordingly, of suggesting a 
suitable time-point for the commencement of the year for which the Nautical Almanac 
would inaugurate the changes corresponding to the requirements named. The latter, 
as has before been said, could come to pass in the year 1890. We would, however, 
ourselves prefer the change to take place, in the first instance, with the change of the 
century. Until that date it would probably be the simultaneous proceeding of all 
astronomers, with general consent, to look forward to this period of transition, and it 
would more easily stamp itself on the memory of all who hereafter would be busied in 
investigations in which exact chronology plays a part.—Papfer on the Washington 
Conference by Otto Struve, Director of the Imperial Astronomical Observatory, 
Pulkowa, Russta. 
III. The reasons for making the change, as affecting astronomers, are :—(1) The 
introduction of the Universal Jay commencing at Greenwich Midnight, and reckoning 
from o to 24 hours makes it inexpedient to have another time reckoning of o to 74 
hours starting from Greenwich Noon. There are already frequent mistakes of date 
arising from confusion between civil and astronomical reckoning, several practical 
observers using the former, which is also commonly employed in almanacs and occa- 
sionally in some astronomical periodicals. The use of ¢Aree different systems of 
reckoning solar time would greatly increase the confusion. (2) The circumstances 
under which astronomical observations are made have completely changed in modern 
times since the application of powerful telescopes to meridian instruments and the 
development of Solar Physics. The change of date at noon in the middle of the day’s 
work has thus, in many cases, become very inconvenient. (3) As regards meridian 
observations, the experience of the past year at Greenwich Observatory (where obser- 
vations are carried on as continuously through the 24 hours as at any other observatory) 
shows that the whole of the astronomical day can be introduced very easily and with 
decided advantage on the whole. (4) In the case of extra-meridian observations, the 
observer usually finds it convenient to work in the earlier hours of the night, so that 
little or no inconvenience would result from a change of date at midnight. Dis- 
coverers of comets and observers of meteors, who observe in the early morning, often 
use civil reckoning, and mistakes of date have, on several occasions within my own 
