622 
NATUKE 
[JANUARY 29, 1914 
the astronomical notes contained in the volume. This 
analysis is especially valuable on account of the way 
in which the astronomical notes in the ‘‘ Adversaria”’ 
are mixed up with others on hydraulics, statics, the 
construction of thermometers (the scale known as. 
Fahrenheit’s is due to Rémer), numismatics, &c. 
These notes all date from the last eight years of 
Rémer’s life (1702-10), although several refer to in- 
vestigations made during his stay in Paris (1672-81). 
The authors dwell particularly on the various ‘dis- 
cussions of the work done from 1704 in Roémer’s pri- 
vate observatory a few miles west of Copenhagen, 
which show him as a great practical astronomer, to 
whom the principal modern instruments of precision 
and methods of observing are due. Thus it is shown 
that it was Rémer, and not his pupil Horrebow, who 
invented the method of determining latitudes by alti- 
tudes observed north and south of the zenith and 
nearly at the same time, now known as the Horrebow- 
Talcott method. In this the result is independent of 
refraction, and a micrometric measure takes the place 
of the reading of graduated circles. Horrebow has 
certainly the merit of having recognised and pub- 
lished the advantages of the method, but there is now 
no longer any doubt that the idea was due to Romer. 
At the beginning of the eighteenth century the 
method of determining time by observing equal alti- 
tudes of the sun east and west of the meridian was 
still in’ general use. R6mer constructed an instru- 
ment for this purpose, in which the telescope was 
attached to a bar suspended vertically from a crook at 
the upper end, and he prepared tables and formule 
for reducing the observations. By degrees the use 
of the transit instrument, as regards which he was 
himself the pioneer, superseded the observations of 
equal altitudes in fixed observatories. 
Roémer also examined the problem of time-deter- 
mination in the vertical of the pole-star; he did not 
arrive at a simple solution, but tried to get over the 
difficulty by constructing extensive tables for twenty- 
seven selected stars. How much he was in advance 
of his time is shown by his having employed the 
formula for correcting transit observations for instru- 
mental errors proposed fifty years later by Tobias 
Mayer. The transit instrument in the prime vertical, 
introduced by R6émer, was employed by him to deter- 
mine the time of the equinoxes by a method which 
was a modification of one which he had described to 
the Paris Academy in 1675, but which, like most of 
his other investigations, never was published. 
‘The authors give a detailed examination of his 
preparations for determining the vernal equinox of 
1702 by this method. In the original method (de- 
scribed by Horrebow) the declination of the sun at its 
upper or lower meridian transit was deduced from 
the intervals of time between the transits over ver- 
ticals near the prime vertical, employing an approxi- 
mate value of the latitude of the place of observation. 
In the method of 1702 the declination of the sun does 
not enter, nor the latitude. The principal reason why 
Romer wished to eliminate the latitude, was, that he, 
like Picard, thought it was subject to an annual 
variation. Without knowing it, these two eminent 
practical astronomers had, in fact, perceived the effect 
both of aberration and of nutation on the apparent 
place of the pole star. R6mer’s method of deter- 
mining the equinoxes is more ingenious than useful, 
since it not only assumes that the clock rate and 
instrumental errors do not change, but also requires. 
that the sky should be clear for at least three conse- 
cutive approaches of the sun to the prime vertical as 
well as for time determinations. 
It might have been expected that the man who had 
discovered the gradual propagation of light, and even 
foreseen the existence of aberration as its necessary 
NO. 2300. VOL. 02] 
consequence, would in his private notebook have left. 
evidence that he continued to be interested in the 
discovery. There is, however,” only an examination 
of the question, whether it would be possible to deter- 
mine the velocity of light by means of lunar eclipses. 
He found, of course (as he had already done in 1677), 
that the velocity is far too great to become perceptible 
in observations of that kind. 
Romer was the only observer who succeeded in 
seeing Mercury on the sun’s disc on May 6, 1707, 
just after sunrise; the authors have computed the 
particulars of the transit by Newcomb’s tables, and 
find that the observation agrees perfectly with modern 
theory. The doubts thrown on R6émer’s observation 
by Halley and Baily have thus been shown to be base- 
less, while Sharp’s supposed observation must be 
rejected altogether. There are many other points of 
interest in this paper, which it is to be hoped will 
become widely known, as it gives a valuable survey 
of the varied activity of a man, who but for his 
reluctance to a his researches into shape and publish 
them would be reckoned among the greatest astro- 
nomers. jk. EDs 
UNIVERSITY AND EDUCATIONAL 
INTELLIGENCE, 
CampripcE.—Mr. D. G. Reid has been appointed 
junior demonstrator of human anatomy for five years 
in succession, to Dr. Rogers, who has resigned the 
office. 
The prize of sol. from the Gordon Wigan Fund for 
a research in chemistry was awarded in the year 1913 
to Mr. H. V. Thompson, for investigations on ‘‘ Some 
Reactions of Diiodoacetylene,’’ ‘‘ Acetylenic Carbon,” 
and ‘The Molecular Weight of Cellulose.” : 
To the detailed report on the work of the score of 
men who have held John Lucas Walker studentships 
at Cambridge University, which occupies many pages 
in the present number of The Cambridge Reporter, — 
the governors of the trust have added these words :— 
“During the twenty-seven years since the John Lucas 
Walker studentship, one of the earliest studentships 
in pathology, was established, 
appeared most likely to carry out pathological inves- 
tigations successfully, whether a Cambridge graduate 
or from some other school, British and Colonial, has 
always been appointed. While the work accomplished 
by the later holders of this studentship is perhaps too 
recent to be appraised, there has been ample time for 
that accomplished by the earlier students to manifest 
its worth and influence, not only upon the future 
careers of the students and upon the Cambridge 
Medical School, but upon the science of medicine. 
Moreover, it is now possible to form a fair estimate of 
the value of this foundation in particular and of 
graduate research studentships or fellowships in 
pathology in general. It would be difficult to cite any 
one position within the Empire which, in the same 
period, has been occupied by a succession of men so 
able, and who have attained such eminence in medical 
research.” 
Lreps.—Mr. Henry Rutson, of Newby Wiske, 
Northallerton, has made a donation of 5ool. to the 
funds of the University. It is only a short time since 
Mr. Rutson made a similar donation to the fund for 
new agricultural buildings. 
Mr. Godfrey Bingley, an accomplished photographer, 
who has been connected for many years with the 
sented a collection of lantern slides, illustrating archi- 
tecture, archzeology, geology, and scenery in all parts 
of England, but especially in Yorkshire. There are 
about ten thousand slides of exquisite workmanship, 
1 and the collection is admirably arranged and cata- 
the candidate who 
Leeds and Yorkshire Geological Association, has pre- 
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