1891-92. ] CIRCULAR-LETTER. 311 
APPENDIX. 
EXTRACTS FROM THE OPINIONS OF ASTRONOMERS AND OTHERS REFERRED TO 
BY THE JOINY COMMITTEE. 
I. (935) Astronomical time reckons from noon of the current day ; Civil, from the 
preceding midnight, so that the two dates co-incide only during the earlier half of the 
Astronomical and the later half of the Civil Day. This is an inconvenience which 
might be remedied by shifting the astronomical epoch to co-incidence with the civil. 
(147). . . This usage has its advantages and disadvantages, but the latter seem to 
preponderate ; and it would be well if, in consequence, it could be broken through and 
the Civil reckoning substituted. Uniformity in nomenclature and modes of reckoning 
in all matters relating to time, space, weight, measures, etc., is of such vast and 
paramount importance in every relation of life as to outweigh every consideration of 
technical convenience or custom. The only disadvantage to astronomers of using the 
Civil reckoning is this—that their observations being chiefly carried on during the 
night, the day of their date will, in this reckoning, always have to be changed at mid- 
night, and the former and latter portions of every night’s observations will belong to two 
differently numbered civil days of the month. There is no denying this to be an 
inconvenience. Habit, however, would alleviate it ; and some inconveniences must be 
cheerfully submitted to by all who resolve to act on general principles. Al! other 
classes of men, whose occupations extend to the night as well as day, submit to it, and 
find their advantage in so doing.—Szr John Herschell’s Treatise on Astronomy-— 
Third Edition. 
II. Much earnest reflection, on the other hand, must be given to the desire 
expressed at the meeting, that Astronomical Time Reckoning should be brought in 
accord with the commencement of the day in civil life. In this matter, astrono- 
mers have not simply to abandon a custom of long standing, and consequently to make 
conditional changes of practice established for many years, but, at the same time, 
astronomical chronology is disturbed, which is easily understood, must exercise a 
marked effect on the comprehension of all problems bearing upon matter. Without 
doubt, the astronomer must make a great sacrifice for the fulfilment of this desire ; but, 
in reality, this sacrifice is not greater than that entailed on our forefathers when they 
passed from the Julian to the Gregorian Notation of Time, or when they altered the 
commencement of the year: a sacrifice of convenience by which we yet suffer when it 
becomes necessary to refer to phenomena of remote dates. At this period, we must 
the less stand in fear of a like sacrifice, when by such means an acknowledged existing 
non-accord between science and ordinary life can be set aside: a non-accord which, it 
is true in individual cases, does not press heavily on the astronomer, but which is a 
constant source of inconvenience for non-professional astronomers who are desirous of 
making use of astronomical information. And in such respect, this sacrifice ceases so 
to be considered and is transformed into an act of public utility with regard to all astro- 
