790 



ECLECTICS ECLIPSE. 



states of the confederation of the Rhine. The conse- 

 quences of 1 1 it- battles of Eckmulil and Ratisbun were 

 very important. The Austrian general Jellacliich 

 was obliged to evacuate Munich, wlu'ch the king of 

 Bavaria re-entered on the 25th. The Austrian main 

 army, strengthened by the corps of Bellegarde, re- 

 tired, under the archduke Charles, to Budweis, in 

 Bohemia, and was concentrated on the left bank of 

 the I >;im 1 1 ><, at the foot of the Bisamberg, and on the 

 Marchfield, ready for the more famous combats at 

 Aspern and Wagram. Charles, however, was not 

 able to save Vienna. Napoleon advanced along the 

 right 1 tank of the Danube, notwithstanding the insur- 

 rection in the Tyrol, and passed the Inn. On the 3d 

 of May, general Miller made an obstinate resistance 

 at Ebensberg, with 35.000 men, but was compelled 

 to retreat to the left bank of the Danube. The French 

 passed the Ems, and advanced to the capital of Aus- 

 tria, which capitulated, May 12. On the 13th, Na 

 I ><>! ron fixed his head-quarters at Schonbrunn. May 

 20, Napoleon crossed to the left bank, and thus 

 brought on the memorable battles upon the March- 

 field, that of Aspern, or Essling, and that of Wagram. 

 This whole campaign is highly interesting and in- 

 structive to a military man, who may derive useful 

 lessons from the conduct of both parties ; from tliat of 

 Napoleon, who followed up a grand plan with unpre- 

 cedented ability and spirit ; and from 1 1 1; it of Charles, 

 who displayed great military skill in liis manoeuvres, 

 as was always acknowledged by the victors. 



ECLECTICS (from the Greek i*Xi*<r<*, select, 

 from i*>.iyu. to select) is a name given to all those 

 philosophers who do not follow one system entirely, 

 but select what they think the best parts of all sys- 

 tems. Their philosophy is also called eclectic. In 

 the history of pliilosophy, tins term is chiefly applied 

 to that sect of Greek philosophers, who strove to 

 unite and reconcile the opinions of Pythagoras, 

 Plato, and Aristotle, and to bring them into one har- 

 monious system. 



ECLIPSE. 



An Eclipse of the Moon is a privation of the light 

 of the moon, occasioned by an interposition of the 

 earth between the sun and the moon ; consequently, 

 all eclipses of the moon happen at full moon ; for it 

 is only when the moon is in opposition, that it can 

 come within the earth's shadow, which must always 

 be on that side of the earth which is from the sun. 

 The earth being in the plane of the ecliptic, the centre 

 of its shadow is always in that plane ; if, therefore, 

 the moon be in its nodes, that is, in the plane of the 

 ecliptic, the shadow of the earth will fall upon it. 

 This shadow, being of considerable breadth, is partly 

 above and partly below the plane of the ecliptic ; if, 

 therefore, the moon in opposition be so near one of its 

 nodes, that its latitude is less than half the breadth of 

 the sliadow, it will be eclipsed. But, because the 

 plane of the moon's orbit makes an angle of more than 

 five degrees with the plane of the ecliptic, it will fre- 

 quently have too much latitude, at its opposition, 

 to allow it to come witliin the shadow of the earth. 



An Eclipse of the Sun is an occultation of part of 

 the face of the sun, occasioned by an interposition of 

 the moon between the earth and the sun ; thus all 

 eclipses of the sun happen at the time of new moon. 

 The dark or central part of the moon's shadow, where 

 the sun's rays are wholly intercepted, is called the 

 umbra, and the light part, where only a part of them 

 are intercepted, is called the penumbra ; and it is 

 evident, that if a spectator be situated on that part of 

 the earth where the umbra falls, there will be a 

 total eclipse of the sun at that place ; in the penum- 

 bra there .will be a partial eclipse, and beyond the 

 penumbra, there will be no eclipse. As the earth 

 is not always at the same distance from the moon, if 



an eclipse should happen when the earth is so foi 

 from the moon ttmt the rays of light proceeding from 

 the upper and loweHimbs of the sun cross each other 

 before they come to the earth, a spectator situated OH 

 the earth, in a direct line between the centres of the 

 sun and moon, would see a ring of light round the dark 

 body of tin- moon ; such an eclipse is called annular; 

 when tin's iiappens there can be no total eclipse any- 

 where, because the moon's umbra does not reach the 

 earth. People situated in the penumbra will perceive 

 a partial eclipse ; and an eclipse can never be an- 

 nular longer than 12 minutes 24 seconds, nor total 

 longer tiian 7 minutes 58 seconds ; nor can the dura- 

 tion of an eclipse of the sun ever exceed 2 hours. 



The cut below will illustrate the phenomena of both 

 solar and huiar eclipses. S is the sun, E the earth, m 

 the moon in conjunction with the sun, and m' in op- 

 position. When the moon is in the position m the sun 

 will be eclipsed by her, but when she is in the position 

 TO' she will be eclipsed by the shadow of the earth. 



The sun being larger than the earth, the earth's 

 shadow is a cone, whose base is on the surface of 

 the earth, and the moon is eclipsed by a section of 

 the earth's shadow. If the earth were larger than, 

 or equal to, the sun, its shadow would either perpe- 

 tually enlarge, or be always of the same dimensior; 

 but, in this case, the superior planets would some- 

 times come within it, and be eclipsed, which never 

 happens. Therefore the sun is larger than the earth, 

 and produces a shadow from the earth of a conical 

 form, which does not extend to the orbit of Mars. 

 An eclipse of the moon is partial when only a part 

 of its disc is within the shadow of the earth ; it is 

 total when all its disc is within the shadow ; and it 

 is central when the centre of the earth's shadow falls 

 upon the centre of the moon's disc. Now, the 

 nearer any part of the penumbra is to the umbra, 

 the less light it receives from the sun ; and as the 

 moon enters the penumbra before she enters the um- 

 bra, she gradually loses her light, and appears less 

 brilliant. The duration of an eclipse of the moon, 

 from her first touching the earth's penumbra to her 

 leaving it, does not exceed five hours and a half. 

 The moon does not continue in the earth's umbra 

 longer than three hours and three quarters in any 

 eclipse, neither is she totally eclipsed for a longer 

 period than one hour and three quarters. As the 

 moon is actually deprived of her light during an 

 eclipse, every inhabitant upon the face of the earth, 

 who sees the moon, sees the eclipse. An eclipse of 

 the sun, as we have said, happens when the moon, 

 passing between the sun and the earth, intercepts the 

 sun's light ; and the sun can only be eclipsed at the 

 new moon, or when the moon, at its conjunction, is 

 in or near one of its nodes. For, unless the moon 

 is in or near one of its nodes, it cannot appear in or 

 near the same plane with the sun ; without which it 

 cannot appear to ns to pass over the disc of the sun. 

 At every other part of its orbit, it will have so much 

 northern or southern latitude, as to appear above or 

 below the snn. If the moon be in one of its nodes, 

 having no latitude, it will cover the whole, disc of the 

 sun, and produce a total eclipse, except when its ap- 

 parent diameter is less than that of the sun ; if it bn 



