Evening star. [volume] (Washington, D.C.) 1854-1972, 1873-04-05


The work upon the new tower and dome a.
the Observatory for the refracting telescope
now being made at Cambridgeport, Mass. has
already commenced, and is being pushed for
ward rapidly. The foundation walls are being
laid, and the entire structure viii be completed
IN accordance with the terms OF the contract
oy the hrst Of July. A one-story brick build-
ing, 10 De used Tor computing room for the
observer, with bath room, closets, &c, is being
erected on the southern front, akd al Joins tn,
90 building: small yestibule, six by thirteen
the foundation for which, of heavy blue stone
Is nearly finished.
THE TOWER
will be q feet high from the ground TO the bas,
Of the dome, and Al feet i'm diameter. The e,-
caVation Tor the foundation is feet deep, ami
the foundation walls, three feet thick extend
ABOUT four feet above ground. In these are
nNeu twenty-four iron anchors to which the
tower is to be secured. A circular sill OF oak
lumber, 5x12 inches, will rest upon the founda-
uon, and INTO this sill will be mortised studs of
OAK umber in alternate pieces of 6xS and 3xs
I.Snes. oh tne top OF these studs will rest an
otner ring OF oak timber 4xs inches forminr
the base of the revolving dome and sripportin7
the rails on which the wheels of the dome viii
with gaVsn ehIor OF the tower will be covered
'eIiof hhished with building paper.
THE Q0AE
will have diameter OF Il feet at its base. ami
helght OF 70 feet from that point. Ii will have
a circular sill for a rest, four by eight inches
and be composed of ribs of one and half inch
White pine pieces; firmly secured together, with
JOINTS broken The exterior OF the dome will
be covered with galvanized iron, and the inse-
rior finished with building paper. The nec4s.
SHY LOT covering the tower and dome as above
uesSTlpeu is TO have an even temperature both
on the exterior and interior Should the atmos
phere upon the inside be warmer it would OF
course peeome rarified and lighter and As soon
as The shutters at the top should be removed tc
make observations, the rariied atmosphere es-
Gaping from the interior would seriously inter
Ieie WIN the observations. 4 balcony four feet
"lue VIII extend around the outside of the tow
err supported on iron pillars resting on ne stona
foundation. This balcony will be about fouT
ieet from the ground, and be continued aions,
old one and the tower ~
The pier or foundation for the new telasrona
VIII be OF stone and brick, and located Inside
OF the tower. First there is an arch OF blue-
stone seventeen feet high, and upon this a hare
Iflck column will support the telescope on
the toP OF the timbers OF the tower win he a
series OF non rails, and upon these the new
oome Will revOlve by means of thirtv-ty-o lar.
Ioh rollers: The machinery for revolving tha
9Ome, winding the clock, &c, will be worked
by turbine wheel at the base driven Inv Pot
niac wafer, otherwise II would require three OF
four men 10 turn il.
The general finish of the addition and it,
architectural Ornaments will coTrasuonh =,
tlose OF the present building The new do-ns
VIII be much larger, though not higher. tbsr
tEe present one. Ii will be constructed i'm sucb
Interference yxit
" oN me Oh dome. OF course the new tele-
scope cannot be brought to bear ON the north
efh hcr,zon directly, being located directly
souti OF the ola dome but will have 10 overInot l
ehay dome to Ioint at a considerable diStscce
tt meath the north star. The telescone i'm IL |
oid dome VIII have about the same syeep A. |
NOW OVERLOOKING the lew dome il necessary |
THE NEw TELESCOPE
'eaW heinz ne tornpfcr-d-is.r,e.,4s,at ,.-......
place at the Observatory by next fall, at least |
e. ghteen months sooner than specified in the /
C ntTact. This will he the largest refractor in
The world, the object glass having a diameter
focal distance 81 feet. The next largest refrac-
tor is owned 10y a private gentleman, MI. New
hall, OF England. the object glass of that being
25 inches in diameter. The instrument now IN /
use at the Observatory is only 8 inches in diane
ter and when the new one shall be mounted the /
observers here will of course be enabled TO make /
much closer and more satisfactory ObSery ations /
than have been obtainable heretofore. The
object glass. alone, OF the new telescope cost
81 eco. 1t was cast in England and finished IN
Massachusetts. where il is now ready for the in
strument. The cost of the new telescope and
its requisite machinery will be about $50 00c,
and the tower and dome about Sl5,0oo
NEW INSTRUMENTS,
to observe the transit of Venus i'm December,
1874, are also being made, consisting OF tele-
scopes, chrOnometers, photographing mstru-
ments, &c, some OF which have been complet-
ed and are adjusted at the Observatory. This
transit will not be visible here however. ami
arrangements are now being made TO send out
parties TO the Indian ocean, South Pacific
China and Japan, where the observations can
be made. Eight parties will be sent out from
the United States; two of which will go from
the Observatory here. All the parties will sal
next summer.
The Naval Observatory here, with the new
telescope, will be better equipped than any
other institution of the kind in existence, The
professors on duty there stand at the head of
their profession, and the Washington Observa-
tory now is regarded as one of the best in the
world