SCIENTIFIC SUMMARY. 
381 
M. Secchi at Rome was 9,08 seconds, which is smaller than that given by 
the tables now in use. Professor Secchi proposed to take a few more 
measures of this element, but this, he says, is very difficult on account of 
the termination of Mercury’s disc which seems to be very faint at the 
edges. Mr. Baxendell at Manchester noticed its shape when touching the 
edge of the sun, as decidedly egg shaped, the small end of the egg being 
next the sun’s limb. The excessive blackness of the planet, as compared 
with the nuclei of the spots, was very apparent. 
New Comet . — A telescopic comet was detected on December 29th, 1861, 
at 3 a.m., at Cambridge in the United States. It was independently 
discovered on January 8th, 1862, by M. Winnecke at St. Petersburgh. 
It was faint when first seen, and became much fainter subsequently. It 
was at its shortest distance from the sun on December 6th, being then at 
a little less than the mean distance of the earth from the central 
luminary. It approached within ten degrees of the pole star on January 
20th. The great comet of July of last year was observed up to January 
of the present year. Astronomers must wait for the publication of all the 
observations, before its real orbit and true periodic time can be finally 
discussed. At present the latter element is doubtful- — one calculator 
(Seeling) making its time of revolution round the sun 419-J- years, whilst 
another (Capocci) concludes it to be 1,796 years. 
Meteors . — Within the present year, M. Petit, of Toulouse, has cal- 
culated the height of the great meteor of September 13th, 1858. He 
finds its height to have been 222 kilometres (about 138 miles), and its 
velocity per second 19 miles. That which was seen and fell in France, 
on December 9th, 1858, was only three miles distant at the time of the 
explosion, and its apparent velocity was about three miles per second. It 
was twelve minutes after explosion before its luminous train had disap- 
peared and violent detonations were heard. 
Saturn . — The ring of this planet disappeared duly (as far as most 
telescopes were concerned), at the calculated time. For some days previous 
to this disappearance, the thin line of light into which the ring had re- 
solved itself was considerably broken, as if various irregularities existed 
on its surface. Captain Jacob on December 4th, 1861, with the new nine 
inch telescope constructed for him by Cooke, detected a thin white line of 
light crossing a dark belt covering the equatorial regions of the planet. 
This was independently seen a few evenings later by Mr. Buckingham, 
and on Mr. Wray pointing his telescope at the planet on the morning of 
December 27th, he was astonished not only to see this (which appears to 
be the edge of the ring,) but also the continuation of this line of light 
projecting beyond the margins of the planet in the dark sky. The ap- 
pearance is given in the accompanying drawing. 
The thin trace of light across the planet seemed like a knife edge and 
was broken. It does not appear that this phenomenon was previously 
witnessed, although looked for by the Cambridge and Pulkowa refractors 
sixteen inch aperture at the disappearance of the ring in 1848. It is a 
striking proof of the improvement of object-glasses of telescopes — for 
which we are wholly indebted to English makers — Messrs. Way and 
Cooke. 
