562 
WA TURE 
4 
[Oct. 7, 1886 
were absorbed by those investigations for which the institution 
was established, I had the satisfaction of obtaining a sufficient 
number of stellar photographs to occupy not only my own life- 
time, but many more, in their measurement and proper compu- 
tation. 
We photographed no northern stars there except the Pleiades 
and the Presepe. Of the Pleiades I brought home sixteen 
plates, with two impressions of the whole group upon each, 
made in five different years, from 1872 to 1882, inclusive. 
Although the centre of the cluster never attains a greater alti- 
tude at Cordova than 34° 50’, some of the plates contain seventy 
stars. All but one of Bessel’s stars are there, which belong 
within the limits of the field, the missing one being of the mag- 
nitude 94, and there are yet other stars of the magnitudes 10, 
to}, and 11. Of the Praesepe there are five plates, and with a 
correspondingly increased number of stars. 
About seventy southern clusters have been repeatedly photo- 
graphed at Cordova, comprising all those of the southern hemi- 
sphere which seemed important, also somewhat more than a 
hundred double stars, being a sufficient number to serve as a 
good test of the method. The total number of photographs 
now on hand is somewhat less than 1300, only few having been 
preserved in which the images were not circular. 
Especial attention, however, was given for many years to 
taking frequent impressions, at the proper seasons, of four stars 
selected, on account of their large proper motion, as likely to 
manifest appreciable annual parallaxes. The refined and 
elaborate observations of Drs. Gill and Elkin, at Cape Town, 
have been made, computed, and published, while the Cordova 
photographs have lain untouched in their boxes. There is but 
one of my four stars, 8 Hydri, which is not included in their 
list. Still, it will be a matter of much interest to apply the 
photographic investigation to the same problem, even if for 
no other purpose than a comparison of the results of the two 
methods. 
I am convinced that the Cordova plates contain a large num- 
ber of stars as faint as the eleventh magnitude of Argelander’s 
scale, and believe that these are much the earliest photographs 
of stars fainter than Mr. Rutherfurd’s of 1865 and 1866. There 
are several plates, covering about a degree square, which cannot 
contain less than 550 stars, and I believe that some of them con- 
tain a greater number. Such are those of the cluster Lac. 4375 
and that near X Carine. 
The region in the vicinity of 4 Carinz, and that magnifi- 
cent tract in Sagittarius which is too densely sown with stars to 
be considered merely a portion of the Milky Way, and yet too 
large and undefined to be regarded simply as a cluster, were 
both of them taken several times, during the years 1875-82, 
in series of overlapping photographs, each containing about 
a :quare degree, and recorded upon a glass surface of 9 
by 12 centimetres. In their present form they are of course 
of small value for scientific use, inasmuch as the stars are 
too crowded for their configurations to be easily perceived ; 
and although these two series form, in fact, maps of considerable 
regions in the sky, still the record is of a very perishable nature, 
and of small avail for use by astronomers until it shall have been 
translated into an enduring and numerical form by micrometric 
measurement. 
In this connection I may say that one of the greatest of my 
present anxieties regarding the Cordova photographs arises 
from a discovery of the ease with which the collodion or gela- 
tine film may become detached from the glass. The Argentine 
Government has assigned a moderate sum for the prosecution of 
the measurements, and with this some progress has already been 
made. It is but right to add that the full amount was given for 
which I asked, Still, it is now quite inadequate, in consequence 
of the unfortunate depreciation of the national currency ; and, 
in the present financial crisis there, I cannot reasonably expect 
more. Yet this matter of prompt measurement appears to me 
at present much more important than it did while I was unaware 
of the facility with which the film can blister and peel. 
_ In 1883, after Mr. Common’s brilliant success in photograph- 
ing nebulas with his great 3-foot reflector, he proposed to me a 
joint arranzement for photographing the whole heavens. My 
work at Cordova was so near its close that it was out of the 
question to undertake anything new; but the immense labour 
requisite for the measurement of the plates would, under any 
circumstances, have tended to deter me. It is an undertaking 
demanding the joint energy, application, and material resources 
of a large number of persons, if the results are to be made avail- 
able for astronomical use ; indeed, I see no other astronomical 
value in the unmeasured photographs than the possibility of 
confirming at some future epoch the existence of relative motion 
previously detected or made probable by some other investi- 
gation, : 
Since then the process of photographic charting is said to 
have been systematically undertaken by the Brothers Henry at 
Paris. I have seen none of their plates; but their sharpness is 
highly spoken of, and the work appears to be prosecuted with 
much skill and very sensitive plates. There can of course be 
no question as to the value of any permanent record whatsoever, 
corresponding to a known date; yet I cannot feel that any 
essential advance is likely to be made in this way until the 
photographic record shall have been brought within the range 
of numerical expression, : 
The measurements of the Cordova photographs, thus far com- 
pleted, are those of the double stars, the four stars with large 
proper motion, of the Pleiades, of the Praesepe, and of the’ 
clusters Lac. 4375 and « Crucis. The corresponding com- | 
putations have been made, as yet, only for a portion of the 
Pleiades impressions, but I am hopeful of completing all these — 
at a comparatively early date. We shall then be able not only 
to compare the results with Bessel’s of forty-five years ago, but 
to test the deduced values of the proper motions by means of 
the photographic determinations of 1865 and 1866. Meanwhile, 
the valuable memoir of Wolf has been published, giving closely 
approximate positions for 571 stars of the group, and Dr. Elkin 
has recently been executing at New Haven a heliometric tri- 
angulation of the principal stars. Our photographic results will — 
haye to be confronted with his delicate heliometric ones; and, 
should they bear this test with tolerable success, it will be all 
that can reasonably be desired. B. A. GouLD 
UNIVERSITY AND EDUCATIONAL 
INTELLIGENCE 
Pror. W. GryLts ADAMS, F.R.S., will deliver, at. King’s — 
College, London, a course of lectures on Electricity and Mag- 
netism and their applications to Electric Lighting, Transmis- 
sion of Power, &c., during the academical year 1886-87. A 
course of practical work in Electrical Testing and Measure-— 
ment with especial reference to Electrical Engineering will also 
be carried on under his direction in the Wheatstone Laboratory. 
In the Wheatstone Laboratory, which is open daily for re- 
search from I to 4, except on Saturdays, there are special 
courses of practical work for students preparing for the Science 
Examinations of the University of London. 
Ir is purposed to celebrate, in a befitting manner, from 
November 6 to 8 next, the 250th anniversary of the founding 
of Harvard University, Cambridge, Massachusetts. The Uni- 
versity was established on November 7, 1636, by an Act of the 
Colonial Levislature, and was named after John Harvard, who 
was a liberal benefactor of the new institution. Harvard is the 
oldest University in North America. The southern portion of 
the Continent possesses one many years older—the University — 
of St. Mark, at lima, founded in 1551 by the Emperor 
Charles V. . . 
SCIENTIFIC SERIALS 
Bulletin de ? Académie Royale de Belgique, July.—Modern 
kinetics and the dynamism of the future, by G. A. Hirn. The 
author replies to the arguments urged by M. Clausius against his 
view of the kinetic theory in its application to the resistance of 
gases. He continues to treat the question in connection with 
his peculiar spiritualistic opinions, and endeavours to overthrow 
the theory now generally accepted by physicists, because of the 
disastrous consequences which he supposes it would have on the 
progress of mankind.—On a class of conjugated polynomes, by 
J. Deruyts. This memoir, which is a further development of 
the author's previous researches, deals more especially with the 
important functions presented by certain polynomes in the | 
approximate calculation of definite integrals.—On the distribu- 
tion of the regenerate nerves, by C. Vauclair. In this paper 
the author deals with the peripheric distribution of the regenerate 
nerves compared with that of the primitive nervous system.— 
Essay on the origin of the Fraunhofer rays in relation to the 
