i a, 
Astronomy. 289 
IV. Astronomy. 
1. Note on the Eclipse of the Sun of April next.—On Saturday the 
25th of April, there will be an eclipse of the sun, which although but 
partial, even where largest, in the United States, will without doubt be 
carefully observed by every astronomer, as it will also be visible in 
Great Britain, and therefore of great value for the determination of his 
longitude from Greenwich, and as it will be the last large eclipse that 
will be visible to us for upwards of eight years, and the last that will 
be total in our vicinity until Aug. 7th, 1869. 
In the English Nautical Almanac and the French Connaissance des 
Tems, the approaching eclipse is called central and annular, it having 
escaped the notice of the computers of those works, that although the 
tabular diameter of the moon is less than that of the sun, it is so nearly 
equal thereto, that a few degrees of altitude will render it apparently 
the greater, and consequently, the eclipse where central, total; but 
even where longest (near the island of Eleuthera) the duration of total 
darkness will not exceed 51 seconds, or the diameter of the moon’s 
shadow, 22 miles. 
By the following table it appears, that the duration of the central 
eclipse on the earth will be 3 344™, and the length of its path about 9000 
miles. For thirteen minutes after the beginning, and about seventeen 
before the end, of the central eclipse, or for about half an hour only, 
it will be annular; during the remainder of the time, or for upwards 
of three hours, it will be total, but so small is the extent of land to 
which the eclipse will be central, and so narrow the shadow of the 
moon, that Sagua la Grande, a town on the north side of the island of 
Cuba, appears to be the only place of note or importance on the earth 
that will see a total eclipse. 
During the remainder of the present century, there will be but five 
eclipses central in any part of the Atlantic States, viz. those of May 26, 
1854, and Sept. 29, 1875, annular in Massachusetts, and that of Oct. 
19, 1865, in the Carolinas; whilst those of Aug. 7, 1869, and May 28, 
1900, will be total in North Carolina and Virginia. 
The following elements of the sun and of the moon, according to 
Burckhardt, were taken from the Nautical Almanac, but those according 
to Damoiseau were very carefully computed for Paris for four intervals 
of two hours each, and thence reduced to the meridian of Greenwich. 
The difference between these lunar tables is sometimes very considera- 
ble, amounting to 15 seconds and upwards; but on this occasion this 
fortunately is not the case, as during the continuance of the whole 
eclipse, the greatest difference in longitude is 24 seconds, and in lati- 
tude and parallax 1} only. 
Sxconp Series, Vol. I, No. 2.—March, 1846. 37 
