106 
POPULAR SCIENCE NEWS. 
[Jui-v, 1S90. 
magnificent instruments vvitli wliich the 
observatory has been equipped, through 
the liberality of its- public-spirited founder, 
James Lick. 
Everyone, doubtless, is familiar with the 
history of the observatory and its eccentric 
millionaire foimder, whose remains now find 
a fitting sepidchre in the massive stone pier 
which supports the great telescope. Under 
tlie conditions of the bequest, a fine road, 
twenty-eight miles in length, has been built 
from the city of San Jose to the summit 
of Mount Hamilton, and visitors are always 
courteously received, and given every oppor- 
tunity to inspect the buildings and instru- 
ments. On one evening of the week, the 
great telescope itself is placed at the service 
of the public, and large numbers avail them- 
selves of the opportunity of looking through 
"the biggest telescope in the world ; " although 
we doubt if the non-professional eye would 
note any great difference between the heavenly 
bodies as viewed through the thirty-six-inch 
object-glass and a much smaller one. A very 
free-spoken tourist expressed a similar feeling 
by inquiring, in a rather disappointed tone, 
"Is that all.?" after a somewhat cursory 
examination of the moon, which probably 
failed to show her the " man" of our satellite 
wandering over its mountains and valleys. 
The ride from San Jose to the observatory 
is in itself a trip worth the taking, the smooth 
road, with its easy grades, passing through 
vineyards and orchards such as only Califor- 
nia can boast of. Arrived at the top, a mag- 
nificent prospect opens out, extending over 
the Santa Clara Valley to the Pacific Ocean 
on the west, and to the snow-capped peaks 
of the Sierra Nevadas in the east. Often in 
the early morning the valley is filled with a 
dense mass of fog, out of which the mountain 
peaks stand like islands, making a scene 
which can never be forgotten. 
As we had followed the process of manu- 
facture of the great object-glass at the Cam- 
bridge factory of the late Alvan Clark with 
much interest, we were naturally very desirous 
to see it in its final position, and to learn 
regarding the results accomplished by it ; 
and, by the courtesy of the director, Professor 
E. S. Holden, every facility was given to 
inspect it, as well as the no less important 
and novel accessory apparatus, without which 
the glass itself would be valueless. Some 
of the best results obtained from the object- 
glass have been in the direction of celestial 
photography ; and it was no small privilege 
to examine the original negatives of the moon 
and planets, which preserve so many minute 
details for future study and examination, thus 
continuing indefinitely favorable conditions 
for observation, which would occur very 
infrequently, and for short periods of time, 
if it was necessary to observe them directly 
through the telescope itself. 
The diameter of the dome containing the 
great telescope is seventy-five feet. It is 
made of steel plates, and weighs one hundred 
and thirty tons ; yet by the turning of a little 
wheel, the dome is noiselessly moved so that 
its window opens to any part of the sk}' that 
is desired. The telescope is fifty-six and a 
half feet long, and weighs twenty-fom- tons, 
and is so poised that it can be moved to point 
in any direction by the turning of a wheel or 
by placing ones hand on the lower end of the 
telescope. The entire floor of the observa- 
tory can be lowered or lifted, by hydraulic 
power, a distance of seventeen feet ; so that 
the observer may sit in his wheeled chair and 
follow the moving telescope from the zenith 
to the horizon. 
The principal function of the object-glass — 
the lens placed in the upper end of the telescope 
— is to gather the light proceeding from any 
object and form an image of it at the focus. 
This image is then magnified by the smaller 
lenses in the eye-piece of the telescope, by 
which it can be enlarged to any desirable 
extent. It will thus be seen that it is the 
light-gathering power which is desired in an 
object-glass, and this is dependent upon its 
area. The object-glass of the Lick telescope 
has an area of i,oi8 square inches, while the 
next largest — that at Pidkowa, in Russia — has 
an area of only 706 square inches; the 
former glass thus has nearly one-third more 
light-gathering power. 
The other apparatus of the observatory is 
well worthy of mention. A twelve-inch 
equatorial telescope is in constant use, and 
is a very valuable adjunct to its giant neigh- 
bor. The meridian circle, the transit instru- 
ment, the photographic laboratory, as well 
as the numerous smaller telescopes, clocks, 
meteorological instruments, etc., are all con- 
structed in the best manner and with every 
modern improvement. Earthquakes are not 
uncommon, and might produce serious errors 
in the adjustment of the instruments if they 
should pass unnoticed ; so a complete seismo- 
graph registers automatically the slightest 
tremor of the earth, upon a sheet of smoked 
glass, showing the time, the direction, and 
the force of the vibration. 
The value of the great object-glass in the 
study and photography of stellar spectra is 
evident, and when its capabilities in this 
direction are fully developed and utilized, 
very valuable results will undoubtedly be 
obtained. A most ingeniflus form of spec- 
troscope has been devised by Professor 
Holden, which, when adjusted to the eye- 
piece of the telescope, can be moved so as 
to bring all parts of the circumference. of the 
sun successively into the field of view with- 
out readjustment. The condition of the solar 
prominences, or " fiames," can thus be ob- 
served in all the solar latitudes at the same 
period without any loss of time. 
The large stafi' of observers, together with 
the mechanics and laborers employed about 
the observatory, make up quite a little colony, 
which is housed and cared for in the best 
possible manner. A bed of fine clay was for- 
tunately found near the summit, and a tempo- 
rary brick-yard was established, which pro- 
duced the bricks used in the construction 
of the buildings, thus saving an expense of 
nearly $40,000 in freight charges. An 
abundant supply of water is found upon the 
mountain, and a daily line of stages to San 
Jose keeps the observatory in constant com- 
mimication with the lower world ; and, 
altogether, the lot of the Mount Hamilton 
astronomers seems a most happy one, want- 
ing nothing, either in material comfort, or 
opportunity for pursuing the noble and 
fascinating study of astronomy under the 
most favorable conditions. 
[Concluded from June number. j 
REVIEW OF MR. ALFRED RUSSEL WAL- 
LACE'S "DARWINISM." 
BY KATHARINE 11. CLAVl'OLE. 
There exists loda^- a great dilTerence of opinion 
as to tlie exact value that should be attached to the 
agency of natural selection in the evolution of spe- 
cies, many eminent naturalists maintaining that 
certain fundamental principles of variation or laws 
of growth have plajed the greater part in the 
production of new organic forms. That species 
arise from species by the natural law of "descent 
with modification," was established by Darwin, 
whose celebrated hypothesis gave the long-looked- 
for support to the philosophy of evolution. One 
other theory, it is true, had been offered, but, as 
stated and illustrated by its originator, — the gifted 
Lamarclc, — it was so beset with difficulties that it 
exercised little influence on the scientific mind. 
That new species of animals could be formed by 
changes in the structure of organisms, appeared to 
be capable of proof; but that these changes arose, 
as Lamarck taught, under the direct influence of new- 
conditions of life, — the neck of the giraffe lengthen- 
ing as the creature stretched higher and higher lor 
leaves; the feet of the duck becoming webbed in its 
ertbrts to swim ; and so on, — and that the modifica- 
tions thus effected were transmissible to offspring, 
could not be accepted without strong evidence. 
This evidence Lamarck was unable to produce, and 
his theory was still further weakened when effort 
directed by the wish of the individual was called on 
to explain changes in the structure of plants. 
Through the impetus given to the study of biol- 
ogy by the hypothesis of natural selection, research 
has been carried into many new regions. Each fact 
that has been discovered has opened the way for 
many others, at the same time giving glimpses 
of ever-widening fields of inquiry. No one natural- 
ist can now attempt to explore more than some 
limited part of the great whole, and yoar by year 
the limits arc being drawn more closely. The more 
the field is narrowed, the greater the number 
of minute and detailed observations that can be 
made in it. There is, therefore, at the present 
time, an accumulation of facts and observations 
that is simply enormous compared with the small 
number that were within the reach of Lamarck. 
Though none of these are found to support extrava- 
gances such as the agency of the wish of the indi- 
vidual in producing organic change, many seem, to 
