50 
THE YOUNG SCIENTIST. 
mone, were obtained by the cod and luilii- 
but tisiiermen, bat I was never successful 
iu keeping- tiiem alive for more than a 
montii at a time, and I have often thought 
that this was due to tlie absence of the 
great pressure of water, and the greatly 
subdued light wliich exists at the bottoni 
of the ocean where they were caught. 
In the English aquaria this same ane- 
mone has been ]vei)t as long as ten years. 
At one time I had seven varieties of Eng- 
lish anemones in my tanks, and curious 
to relate they all outlived botlithe Ameri- 
can and German varieties, some having 
lived from the opening of the aquarium 
till its closing, a period of four years. 
I also had several collections of Ber- 
muda anemones, but they too were deli- 
cate, with the exception of a medium 
sized variety of a magnificient light and 
dark maroon color. This variety was 
very hardy, and reproduced both by di- 
vision and eggs, wliich it ejected from its 
mouth in large quantities. When collect- 
ing anemones at night time at Wood's 
Hole, on the Massachusetts Coast, the ten- 
der skin on the inner part of my fore-arm 
was constantly blistered. This arose 
from the fact that the anemones when 
being taken with a scraper throw off 
and surround themselves with quan- 
tities of a transparent and gelatin- 
ous fluid, wliich when applied to the 
tongue instantly blisters it. They are un- 
doubtedly i:>rovided with this peculiar 
material by nature as a means of defence. 
They are also provided with numerous 
lasso cells in which very minut;e, long, and 
thread like " lassoes " are curled up, and 
when capturing a live fish they project 
them from all directions. With these in- 
visible threads the fish is not only entan- 
gled, but is also stung and held fast with 
the aid of the tentacles. As an illustration 
of the wonderful reproductive properties 
of the anemones, and their great tenacity 
of life, I will, in the next number, relate 
several interesting experiments that I 
have made when curator of different pub- 
lic aquaria. 
The Late Transit of Venus ; Its Nature 
and Utility. 
BY BERLIN H. WRIGHT. 
— There lives more faith in honest 
doubts, believe me, than in half the 
creeds— Tennyson. 
N event which attracted great at- 
tention from all classes, and 
will be forever remembered by 
astronomers as the greatest as- 
tronomical event of the nineteenth cen- 
tury, was the transit of the planet Venus 
across the sun's disc on the Gth of last De- 
cember. The unscientific naturally ask 
the reason of the great commotion made 
by the passage of our sister placet be- 
tween us and the ruler of our system, ap- 
pearing simply as a small black spot 
moving slowly across the fiery face of the 
sun. Admitting that it is a very unusual 
occurrence; that but four such events 
have occurred of which the world has 
record, and that the next one will not oc- 
cur until June, 2004, aside from these facts, 
why have so many hundred thousand dol- 
lars been expended in fitting out expe- 
ditions to distant parts to observe this 
transit? The answ^er is that through this 
phenomenon astronomers hope to solve a 
celestial problem which has baffled the 
skill of the most learned heads for 4,000 
years— the actual distance from our earth 
to the sun, and from that as a base of cal- 
culation, the distance of all the other 
planets from the sun, and in fact that dis- 
tance is used as a " base line " from which 
all the other elements of the solar system 
are computed. Before explaining how 
these results are brought about we will 
explain more fully the nature of the 
phenomena. 
Venus revolves about the sun once in 
225 days, and the earth in 365 days. These 
are called siderhil revolutions, or revolu- 
tions as seen from the sun. But to an in- 
hal)itant of the earth Venus has not made 
a revolution around the sun, because at 
the end of 225 days she is not in the 
same apparent place, with respect to 
the sun, as at starting. Suppose the 
planets to be in conjunction at the points 
b and a in Fig. 1. When Venus has made 
a complete revolution the earth has only 
reached the point c. It takes Venus 25 of 
her years to overtake the earth, or to 
come into the same position with regard 
