DECEMBER 1, 1899. | 
ten integrals of the problem of n bodies for 
forces involving the coordinates and their 
first and second differential quotients. 
The conclusion was reached that the new 
potential function W must be an arbitrary 
function of the mutual distances and rela- 
tive velocities of the n bodies and must not 
contain the time explicitly, in order that 
the ten integrals should hold. In a com- 
munication to the Academy of Sciences of 
Leipzig on Jan. 9, 1899, Professor A. Mayer, 
of Leipzig University, has recently taken 
up the same problem. His investigation 
deals with the problem in a more general 
way and has brought to light an oversight 
of mine in the above definition of W. Fol- 
lowing this W should, in addition to the 
arguments mentioned above, contain the 
differential quotients of the mutual dis- 
tances. It is my intention to give a de- 
tailed account of Professor Mayer’s paper 
in one of the next issues of the Astronomical 
Journal. 
A. Hatt, Jr.: The Aberration Constant from 
Meridian Zenith Distances of Polaris. 
A series of measures was begun by the 
author with the meridian circle of the 
Detroit observatory of meridian zenith dis- 
tances of Polaris, with the idea of deter- 
mining the aberration constant and the 
latitude variation. 
Measures were made above and below 
the pole, direct and reflected, but the num- 
ber of reflected observations has been rather 
small. A rough reduction of the observa- 
tions made between May 1898, and July 
1899, gives the following values for the 
aberration constant : 
Direct. Reflected. 
Upper culmination 207.60 207.66 
Lower culmination 20 .58 20 .40 
M. B. Snyper: The Phonochronograph, and 
_ ts Advantages in Certain Astronomical 
Observations. 
In all kinds of astronomical observations, 
SCIENCE. 
793 
where phenomena, especially of an unpre- 
dicted character, rapidly succeed each other, 
it has invariably been found extremely diffi- 
cult to make time records that can subse- 
quently and with certainty be identified 
with the phenomena. Even with tried 
assistants as recorders, and with a pre- 
arranged code of chronographic signals 
there is usually a double failure ; first, the 
proper records are not made by the assist- 
ants, and secondly, the time signals can 
not be satisfactorily identified. 
The phonochronograph, as for brevity I 
designate a high grade phonograph also 
transformed into an efficient’ chronograph, 
seems fully to obviate the difficulties men- 
tioned. The instrument records any vocal 
expression made by the observer along with 
a simultaneous sound automatically pro- 
duced every second or two by the clock or 
chronometer. The record both for time, 
and for character of phenomena, is un- 
biased, absolutely identifiable, and can be 
read off without introducing any reac- 
tion time, excepting that originally enter- 
ing. 
The instrument consists of a phonograph 
whose cylinder rotates uniformly, and 
whose sliding carriage, which by turns bears 
both the recorder and the receiver, also 
has attached, near a second mouthpiece, a 
small electromagnet whose armature is at- 
tached to a light wooden hammer, which 
at each closure of the electrical circuit by 
the clock, strikes a small resonating box 
placed opposite the second mouthpiece. 
With properly selected resonating box, it is 
found that not only can the time signal al- 
ways be read off by ear as distinct from the 
vocal record, but be visually distinguished 
as well. For the purpose of reading off the 
time record, so as not again to interpolate 
a reaction time, the sliding carriage also 
bears a microscope of moderate power, 
which is placed at an angle of about 90 de- 
grees back of the recording diaphragm and 
