The Sun.
London, England, 1860-10-25 00:00:00

THE 82'EE,

THE S.ECULAB CHAYGE OF THE EART.II'S
011 BIT.

Mr. J. It. Hind, in a letter to the Times, says:—
Several inquiries have been lately addressed to me
with reference to the present state of our knowledge
of the secular inequalities of the earth's orbit, and
its bearing upon the general change of climate
which some geologists recognise and attribute to a
great variation in the obliquity of the ecliptic.
I have reason to believe that the results of the
most recent and complete investigation on the
subject, that of M. Leverrier, are but little known
except to astronomers in this country.
Independently of those inequalities in the orbits
of the planets which are termed "periodic," and
which go through their variations in a few hundred
years at the utmost, there is a class requiring periods
of vastly greater length for their entire exhibition,
which aro 'yet within the grasp of the physical
astronomer, who can define their limits without the
chance of material error. They arise from the slow
but accumulative attraction of the planetary system
upon each of its members, whereby in a cycle of im-
mense duration every orbit is more or less dis-
turbed, though from the nature of the perturba-
tions the planes and eccentricities are necessarily
kept within certain limits. This disturbance it
has been M. Leverrier's object to define.
In the case of the earth it is shown by the French
mathematician that the greatest possible deviation
of the plane of the orbit from the position it occu-
pied in 1800 is 4 deg. 52 min. one way or the
other, end it is easy to see from the form adopted
in the calculations that this result is not liable to
an uncertainty of more than five or six minutes.
Hence it follows, that the greatest possible dis-
tance of the tropics from the equator is 28 deg. 20
min., and the least 18 deg. 36 min. The eccentri-
city is found to attain a maximum included be-
tween the limits 0.06 and 0.08, the most probable
value being 0.078; consequently, assuming the
earth's mean distance from the sun to be
95;365,000 miles, the difference between her
greatest and least distances may amount to nearly
15,000,000 miles ; while, on the other hand, there is
apparently nothing to prevent her orbit becoming,
for a time, sensibly circular. This, however,
will not take place during the present oscilla-
tion. After the lapse of about 24,000 years
from this epoch, a minimum of 0.003 will be at-
tained, whereby the difference between the earth's
extreme distances will be reduced to 500,000 miles.
The followin g table, exhibiting the distances of the
tropics from the equator, and the effect of the ellip-
ticity of the earth's orbit upon her distance from the
sun, for periods of 10,000 years, reckoning back-
wards from 1800, is founded upon M. Leverrier's
theory. I give his results in this form as being
more suitable for a popular communication than
that employed in the original memoir :
Differences loetween
Distance of the the Earth'ssreatet
Tropics from and least Distances
the Equator. from the Sun.
Deg. m. s. Miles.
100,000
10,000
80,000 ..... 22 857
70,000
60.000
50,000
2 ,000
27 6•••• • • • • 0'4
099000
40,000 .... 27 30 56 ..... • 2'SSO,OOO
30,000 .... 27 9 46 • • ...... 3580,000
20,000
10,000 .. 24 52 30 ......
... 3,201,000
0 . • 23 27 55 .......

Years
before
1800.

--------
TIIE ROAD ligniDEß.
ROAD, Tuesday. Tuesday.—Some degree of excitement hag
revived again in this place owing to the re-
beention of the police inquiries in the neighbour-
hood. The discussion last week at the Wilts
Sessions appears to have reanimated. the authorities,
made ' On
and some suggestions which have. been made, and
scene of their former exploitshouse-,
facts trivial in themselves which have been
corn.
munictted to the police,
.have led them again to
Meredith
revisit this
Sunday Mr. Saunders, the. barrisetaeQtr.t,ain.
inquiries igating asnteawte...
senal inspection of the neighbourhood and the a per-
and on Monday and to-dayinlC,
are directed
whether the
and Mr. Foley have been
It is believed that their
in part towards ascertaininc,
merit made by Mr. Saunders, at Marlborough,
that the gas light was burn
burning over
up till eleven o'clock' on the morning of the mur-
der, the hall door
is founded on truth;
possibility of the and aho as to the
murder having been com-
mitted by a female inmate.
criminated, under
atu of the house, not hitherto
the influence of monomania.

It is stated with confidence here, by those who
have been generally well informed, that Mr.
Saunders is deputed to proceed to London tomor-
row, to h ave an interview with the Home Secretary.
The police assert their determination not to let the
matter drop, and still express confidence in their
ultimate success. Mr. Kent has decided to remove
to his former residence, Boynton House, near Cors-
ham, which is his own property, and will probably
do so at Christmas. His anxiety to leave is not to
be wondered at, when it is remembered how inve-
terately his house is haunted. Only last Sunday
scores of persons found their way to the spot, and
one large party of youths entered the premises andt
began exploring the grounds. On Mr.
challenging them as to what business theeywbarq
there, they answered that a Governmen
rcould he
was offered for the nightdress, and blow
expect them to find it if they were no
come in ? It was only on the police beans
"lA'
that they took their departure. :valio_w_fc,lfotor