Weekly national intelligencer. [volume] (Washington [D.C.]) 1841-1869, 1847-10-30
ASTRONOMICAL.


CAmBnIDeE, (MAss.) Der. %, ls47
Messrs. GALES & sEAToS In my letter Of May 2O.hl
published in your paper of May 3d. expressed the opinion
founded on Prof PsRcEs calculations that Neptune doe
not account for the residual perurbatons of Uranus Th
opon was based on the result of very absruse and minute
computations not then susceptible of popular explanation
circumstances OF recent have afforded remark
ape cohhnaon OF this opinion, and have opened the
lot an easy illustration suboin the copy which have bee
permitted to make Of letter Of Prof PEIRcE to the editor
the Boston Courier which will appear in that Journal
HARvARD UNIVERSITY, Ger. 90, ls47
"MAsS OF NEPTUNE
"Ihe AsTnoNoaIscHE NAcHaIcnrES Of September l6th|
SNo. Of contains communication from Mr.. LAssELL of
Liverpool OF his observations of supposed SATELLITES M
NEPTUNE They to be conclusive in favor of the exist
ence OF such satellite and afford basis for a rough compu
talon OF the mass OF the primary He has given eleven da
of the position of the satellite corresponding 10 as
dates OF observation, four Of which in 1916 and seven IN
ls47 careful examination of these diagrams shows that
the satellite must have made eleven evouons abont
It's primary from It's superior conjunction December s 1896
to the same in July 23d s4 and that period Of reyo
ton must have been 81 days 1875 days. The latter o
these periods seems most consistent with the observations Of
lS47, the former with those of 1916. The longer period
seems therefore 10 be the most probable but shall adopt the
latter because gives rather larger to Neptune
Mr. Lassel has also given several estimated distances Of
the satellite from Neptune, which he has stated to be
more than four dameers of the planet By comparing the
the satellite with the planet find the greatest eIongaon Of
the satellite from the primary to be probably dameters
and none OF the observations give great distance
dlameers Of Neptune But the diameter Of Neptune
sured by Gale, Encke, Chals, Walker and MITCHELL is
abou2 seconds and certainly less than seconds of arc
The probable mean distance of the satellite from Neptune is
therefore about 20 seconds of arc.
eli, however, the distance of the satellite assumed
to be thirty seconds and the time of revolution 81 DAYS the
mass OF Neptune be easily computed be oneha the
mass OF Uranus instead of being twice large that of
Uranus, which the required by Leverrers Adj
amss theories. The observations of Lasse them seem to
prove that Neptune cannot haze than one fourth partof
the mass OF The planet Of theory and that its probable mass
IS not more than one.fffeenth part ofhhat Of theory
, ms extraordinary deficiency OF mass, combined with
that of eccenticy, down the effective Neptune
upon Uranus to quite fng affair The unexplained re-
guiaritles OF motion of Uranus amount hundred and
eighty seconds, of which Neptune with his present orbit and
the greatest possible mass consistent with asscs observa
TONS would not account for than tenty seconds and
does not probably account for than foe seconds
This speculation depends for its support upon LassehS
estimated distances but the most rigid scrutiny of these es
mates shows them to be consistent with each other there
fore worthy of all confidence gives the final blow to the
most magnificent structure which human genius has ever
erected.
"Yours, truly, B. PIERCE"
have laid before your readers these researches Of
Prof. PIERCE and have only add that careful examna
ion of Lasses diagrams and of all the particulars the COM
,uatons has given the unhesatng confidence in
heir accuracy which expressed last spring in the more abb
truse researches of that distinguished astronomer
Whoever would revive the theory that Neptune is the hy
'othetcal planet of Adams and Leveer aside the
wo well established observations of Laande in 1885, and
must explain away each of the diagrams (eeven in nuber
Mr.. Lassell Neither the observations of Lalande nor of
.assell can be reconcied with such a theory.
planet that only impress period of twenty days up
satellite distant much further than is from
is have much greater than the earths which
mpresses period of 81 $40 days upon Now if
We take either Adams, Leveries Peirces tables Of
he perurbaiions of Uranus by Neptune, shall find that if
Neptune had not greater than the earh it could
dispace Uranus than three seconds of arc
whereas the displacement of Uranus hitherto unexplained
'0 according to Adams 1873" according Leverrier and
80" according to PIERCE.
1t may strange that Lasse should have with his
Newtonan reflector of only two feet aperture satellite which
euded the searching eyes of the Of Pukova
Cambridge, England, Cambridge New England, and Gin
inna with their great reactors appears however, from
remark of Mr. Lasel that by using Fraunhofr prism
tead OF plane mirror to change the direction of the rays the
ght of his reflector is great that of ordinary Newo-
Of thirty inches aperture Now such Newtonian would
cceive twice many rays of light from the satellite as any
# these great refractors.
Yours, respectfully,
SEARS G. WALKER.