The daily exchange. [volume] (Baltimore, Md.) 1858-1861, 1859-09-21
From the Proridence Journal, Sept 49,


Miss MIrCHELLs TELESCOPE AND OBSERVATORY
me mechanism OF the telescope is probably not ex
celled by those manufactured in Europe. Its focal
strength is between five and six feet and the clear
aperture of the object-cass is FIVE inches 1t is
mounted equatorially, according to the German
method, and furnished with graduated circles for
the determination OF the positions of the heavenly
objects. The circle for measuring right ascensions
is divided to single minutes. but BY means of YER
nier reads to five seconds of time. The declinaton
circle, by means of the vernier, reads to ten
seconds of arc, but by accompanying microscopes
single seconds NAV be determined with toler-
able accuracy. 1t is furnished with clock
work on the plan of Fraunhofer, and so
regulated by Prof Bonds spring governor as
constantly to counteract the effect of the earth's
rotation, keeping the object in that part of the field
OF view which may best comport with the
convenience Of the observer 1t has eight eyepieces
with powers ranging from seventy-fve to three
hundred and fifty. 1t is furnished also with far-
position mcrometer of exquisite workmanship. The
telescope plays upon stand composed of slabs
OF iron intersecting each other at ight angles and
resting on four points adjusted by foot-screws.
This rests pier of solid masonry, surmounted
by mass of granite. The base of the pier is laid
so low that the severest frost cannot affect it, and
the whole is isolated from the surrounding earth
by beach sand, securing it from the tremOr to which
1t would otherwise be exposed from passing carria-
ges on road, unpaved at a distance of fifty yards
The great Russian astronomical observer, Strive
has said that observatory should be a covering
for telescope Either from this precept or from
her observatory in such manner as merely to shell
ter the instrument On entering it, however it is
found to possess all the needfu equipments of
more costly establishment. 1t is a circular build
ing, eleven feet in diameter and scarcely more in
height, covered with an ordinary roof made to re-
volve on cannon balls. By this means a narrow
aperture in the roof is easily brought the point
of the heavens under inspection AS the chief oh
ject of Miss Mitchell is devote the instrument to
scientific work, the whole period since its co4gtruc
ton has been employed in making those nice ad-
Justments so necessary to useful results.
QUEER TRADEs.-Man~ years ago, when rice was
dear in Eastern China, efforts were made to bring
1t from Luzon, where it abundant. At Manl-
la there was, however, passed singular law, to
the effect that vessel for China should be allow
ed to load with rice unless it brought Manila
certain number of cages full of the little ''butcher
BIRDS, well known to ornithologists. The reason
for this most eccentric regulation simply was thBt
the rice in Luzon suffered much from locusts and
! these locusts destroyed in great numbers by
| the butcher birds.
| somewhat similar business is carried on be-
tween England and Zealand This latter country,
at particular seasons is invaded by armies of cat
terpillars, which clear of the grain crops as com
! pletely as if moved down by a scythe. With the
| view of counteracting this plague, a novel impor-
| tation has been made. 1t is thus noticed bv the
! Southern Cross: "Mr, Brodie has shipped 300
sparrows on board the Swordish, carefully selec-
ted from the best hedgerows in England. The food
| alone, he informs u.s. put on board for them, cost
Els. This sparrow question has been long stand
ing joke in Auckland but the necessity to farmers
| of small birds to keep down the grubs is admitted
| on all sides There is no security in New Zealand
against the invasion of myriads of caterpillars,
| which devastate the crops"
The most singular branch of such traffic is the
toad-trade. On some of the market gardens near
| London, as many as five crops are raised in one
year, the principal object being however to raise
the finest possible specimens for high prices I'm
der such system of culture, sugs and other in
sects very formidable fees, and to destroy them
tOads have been found useful as to be purchased
at high prices. AS much as dollar and half a
dozen is given for full grown lively toads which
are generally imported from France where thev
have also been in use for long time in an insect
vorous way.-Phila. Bulletin
SCHOONER IN DISTRESS IN NEW YORK BAY-Ex.
IRENE DEsTITUuoN.-The schooner Sailla from
Jacksonville, Florida was boarded yesterday after
noon in the bay by police-boats crew No q the
"union being down." She was found to have five
feet water in her hold, and the crew, five in nun
Der, were in starving condition, there being ony
pound of bread and half peck of -four on board
The men were too weak to work at the pumps OF
raise the anchor. The boat had been lost at sea
some days previous. The captain had abandoned
the vessel in the morning some hours before she
was boarded, in shore-b boat, and seems to have
made no provision for the They were taken
on shore and provided for by Sergeant Brevoort
The names OF the sufferers are-Sidney A. Austin
mate; Frank Kane, Joseph Anderson, Allen McKen
zie and Henry Howard, seamen.-N. Y. Times.
Two mills in Kanawha county, Va, are turning
out l,2O0 gallons of coal oil daily.