No. Names in Astronomy. 23, Apis Musca ................... English Names. ......The Bee, or Fly 24, Chameleon, at the? S. pole 25, Triangulum Austra lis, on the antarc- The South Triangle... 5 tic circle 26, Piscis Volans ......... The Flying Fish 27, Dorado, at the S. pole of the ecliptic The Sword Fish 28, Toucan...... 29, Hydrus The American Goose. 9 ...............The Water Snake...... 10 30, Sextans, S. of Leo ...The Sextant..... 41 ..... 31 5 31, Monoceros ...... .The Unicorn.............. .......... 32, Crux, by Centaurus... The Cross 33, Officina Sculptoria, The Sculptor's Appa-12 34, Circinus, E. of Cen- The Compasses ....................... taurus 35, Brandenburgium Sceptrum,S.W.of Orion 36, Equuleus Pictorius,7 The Sceptre of Bran- 13 denburg near the S. pole of The Painter's Easel... 8 the ecliptic 37, Fornax Chemica, by The Chemist's Furnace 14 38, Horologium, S. of} The Clock............... 12 Eridanus the rigging of The Mariner's Compass 8 Argo Navis 44, Recticula Rhomboi dalis, antarctic The Rhomboidal Net... 10 Total number visible by a telescope 3478, forming 94 constellations. The above constellations may, in some measure, agree with the number commonly found on globes; but it appears, that the discovery of stars keeps pace with optical improvements; for on Bardin's 18-inch globes there are depicted upwards of 6000 stars, clusters, planetary, nebulæ, &c. To enter into a particular description of these would exceed the limits of a Treatise on the Globes, we shall therefore conclude with the words of Dr. Herschel and M. De Lalande; "In passing rapidly over the heavens with his new telescope, the universe increased under his eye; 44,000 stars, seen in the space of a few degrees, seemed to indicate that there were 75,000,000 in the heavens." Memoirs of the Academy at Dijon, 1785. The same idea is corroborated by Dr. Herschel, as may be seen in the Philosophical Transactions. "In the most crowded parts of the Milky Way, he has had a field of view of 588 stars, and these continued for many minutes; so that in 15 minutes not fewer than 116,000 stars have passed through the field of his telescope." CHAP. VI. ECLIPSES. EVERY planet and satellite is illuminated by the sun, and casts a shadow towards that point of the heavens which is opposite to the sun. This shadow is the privation of light in the space hid from the sun by the opaque body that intercepts his rays. An eclipse of the moon happens only when she is full, and is produced by the moon's passing through the shadow of the earth: which occurs when the earth is in a direct line between the sun and moon. If the light of the sun be kept off from the whole body of the moon, it is a total eclipse; if from a part only, it is a partial one, and is expressed by the number of digits that are darkened. An eclipse of the sun, is when the moon, being in a right line between the sun and the earth, hinders the light of the sun from coming to us, and happens at the change only. If the moon hide from us the whole body of the sun, it is a total eclipse; if not, it is a partial one: when the moon changes at the greatest distance from the earth, its dark shadow terminates * Digits. See note, Prob. xxxviii. Terrestrial globe. in a point before it reaches the earth, and, to those immediately under it, the sun's edge appears like a luminous ring all round the body of the moon, and is called an annular eclipse. Besides the dark shadow of the moon, there is another fainter one, which encompasses it, called the penumbra, which exhibits different degrees of shadow upon those parts which are only partially deprived of the sun's rays. The greatest dark shadow of the moon covers only a spot on the surface of the earth, equal to about 180 English miles broad; but the penumbra, or partial shadow, may cover a space equal to 4900 miles diameter, and, if it falls obliquely on the earth, it stretches out into an elliptical form. An eclipse of the moon begins always on the eastern side, and of the sun on the western side. The number of eclipses in any year of both luminaries cannot be fewer than two, nor more than seven; the most usual number is four, and it is very uncommon to have more than six. Eclipses of the sun are more frequent than those of the moon, because the sun's ecliptic limits are more extensive than the moon's; but we have more visible eclipses of the moon than the sun, because eclipses of the moon are seen from all parts of that hemisphere of the earth which is next them, and are equally great to each of those parts; but the sun's eclipses are |