594 
PHILOSOPHICAL SOCIETY OF WASHINGTON. 
Phil. Soc.; also Proceedings Amer. Assn., Buffalo meeting]. This difter- 
8 10 
ence, corrected by -f etc., of column 6, gives Nos. 12,14,15, 
16, and 17, the differences between the two systems for 1883, 1865,1838, 
1800, and 1755. Columns 12 and 11 are closely alike, as they should be ; 
the only differences, of a tenth of a second, are about the pole and about 
declination 45°, and are probably due to the asterisked stars of the 
Ephemeris, whose declinations do not depend on Boss [see B. J., 1884, p. 
—, 86 —]. As column 14 gives the reduction to Boss of the later Pulkowa 
declinations at their own epoch, it may be of interest to examine it. No. 
18 gives the residuals of this column, after subtracting the simple correc¬ 
tion x |~g (54° — 8); the difference thus practically disappears, except close 
to the pole and within 15° of the Pulkowa horizon. This is a striking 
demonstration of the equable character of the later Pulkowa scale, and if 
the corrections are taken as showing an error in it, this error is naturally 
to be ascribed to the adoption at Pulkowa of two large refractions, a cor¬ 
rection which may possibly be smaller south than north of their zenith. 
Column 19 gives the difference between Auwers’ system of Publication 14 
and that of Astron. Nachr., vol. 64 (see Pub. 14). No. 20 = No. 19 + No. 
15 shows the reduction to Boss of Dr. Auwers’ former system. The best 
epoch of this system differs from that of the Fundamental Catalog by 27 
years, about a fourth of the interval from Bradley’s observations (1755- 
1865); hence if the places of Auwers for 1838 have 16 times the weight of 
Bradley’s places they are as suitable as his for the deduction of proper 
motions. Dr. Auwers, in fact, forms them from a mean of fourteen observa¬ 
tion catalogues, each having weight 1, while he allows to Bradley but half 
weight, and since 14 : \ > 16, it seems to follow from his very rule of pro¬ 
cedure that the proper motions of the Astron. Gesellsch. Fundamental 
Catalog would have been better had he based them exclusively on com¬ 
parison with this earlier system, making no use at all of Bradley. As 
Professor Boss proceeds upon this very theory, his close agreement with 
Auwers’ earlier system is not surprising; it would be closer still but for 
his inclusion of some catalogues (as the Pulkowa, 1845) not then accessible 
to Auwers. Column 22 gives Boss’ correction to Piazzi, and No. 21 == No. 
22 — No. 16 that of the Publication 14 system. The difference in size be¬ 
tween these columns is noteworthy, though no considerable systematic 
weight is generally allowed to Piazzi. Column 23 gives the correction to 
“Greenwich 1861” in the fundamental system, which, as Dr. Auwers 
derives proper motions from comparison of this with his reduction of 
Bradley, is taken as his systematic correction of Bradley. No. 24 = No. 
23 -j- No. 17 is therefore Boss’ correction to Auwers’ Bradley. A careful 
direct comparison of the two is desirable. Professor Newcomb has pub¬ 
lished one (“Standard Clock and Zodiacal Stars”) for the neighborhood 
of the ecliptic. Treating the corrections found by him as a function of 
declination and smoothing them, column 25 is derived, furnishing a rough 
check on No. 24. The next two columns contain Boss’ correction to 
Bessel’s Bradley for stars about the ecliptic and between -p 15° and —15°, 
