46 



THE POPULAB EDUCATOR. 



inclinations of their axes and orbits to the ecliptic, or path in 

 the heavens in which the sun and planets move ; their periodic 

 times, or times of a complete revolution round the sun, as far 

 as they are known ; and the axial time of rotation occupied by 

 each planet. Further particulars respecting the planets and 

 their satellites we must reserve for our Lessons on Astronomy, 

 otherwise we shall lose sight of those on Geography. We may 

 remind our readers that the actual existence of Vulcan has since 

 been confirmed. During a total solar eclipse on July 28th, 

 1878, visible from America, two independent observers, Pro- 

 fessor J.-C. Watson and Professor Lewis Swift, discovered a 

 light object near the sun, which has since been identified with 

 Lescarbault's planet. In this table the planets are arranged 

 according to their distance from the sun. 



TABLE OF THE PRINCIPAL PLANETS OF THE SOLAR SYSTEM. 



In the preceding table it will be observed that the new planets 

 are found in the space mtei-mediate between Mars and Jupiter. 

 These planets were discovered in this space because they were 

 sought for; and the origin of their search is curious. Kepler 

 had discovered that the distance between Mars and Jupiter was 

 anomalous as compared with the distances between the other 

 planets, that it was greater in proportion to their distances 

 from the sun, and he strove by some analogies of Nature to find 

 out the reason, but failed. Titius, a professor of Wittenberg, 

 in Saxony, endeavoured to discover the law of progression in the 

 distances of the planets, and to a great extent succeeded. This 

 discovery was published by Bode, in 1772, in the Connaissance du 

 del Etoile; and hence it is usually called Bode's law. It is the 

 following : Calling the earth's distance from the sun 10, it was 

 found that the distances of the other planets with that of the 

 earth were very near to one another in the proportion of the fol- 

 lowing numbers : 



Planets Mercury, Venus, Earth, Mars, Jupiter, Saturn. 

 Numbers 4, 7, 10, 16, 52, 100. 



On further inquiry it was discovered that these numbers were 

 related as follow : 



4 = 4. 



7 = 4 + 3. 

 10 = 4 + 3 x 2. 

 16 = 4 + 3x2x2. 

 52 = 4 + 3X2x2x2x2. 

 100 = 4 + 3X2x2x2x2x2. 



An inspection of the foregoing series will show that between 

 16 and 52 there should be another number, 4 + 3x2x2x2, 

 or 28, to make its progression regular and complete, and this 

 encouraged the belief, originated by Kepler, that there was a 

 planet revolving in an orbit between those of Mars and Jupiter 

 that had not yet been discovered. 



That there were good grounds for entertaining this idea was 

 further shown by the discovery of Uranus, when it was found 

 that its distance from the sun represented by 191 '93, supposing 

 the earth's distance be 10, agreed closely with the distance at 

 which it should be according to Bode's law, namely, 4 + 3x2 

 X2x2x2x2x2, or4 + 3x64= 196. Astronomers 

 in all parts of Europe anxiously searched the field of the heavens 

 for the planet that was supposed to be whirling through 

 illimitable space between the orbits of Mars and Jupiter, and 

 the supposition was shown at last to be true by the discovery 

 of Ceres, the first of the long list of minor planets, by the for- 

 tunate Italian Piazzi. 



RECREATIVE NATURAL HISTORY. 



THE BUTTERFLY. 



" WILL he catch it ? Does that thoughtless little imp know what 

 a creature of beauty he is trying to crush ? Well done, bright 

 fairy of the spring ! that last wave of thy sun- tinted wings has 

 carried thee over that blooming hedge now far away from the 

 baffled, puffing, red-cheeked schoolboy." Such were our reflec- 

 tions as we once watched " my noble English boy " in hot pursuit 

 of a " Swallow-tail" (Papilio* Machaon) butterfly. (See illus- 

 tration, page 48.) " Kill, kill," were the words written on young 

 Hodge's face as with determination, worthy of a Briton, he 

 chased the winged type of beauty. At first it seemed two to one 

 in favour of the boy ; nearer and nearer he came, up went his cap 

 full at the " Swallow-tail." It was so well aimed, that the insulted 

 butterfly indignantly swept into a neighbouring field, leaving the 

 young hunter in a rage at the useless expenditure of so much 

 toil. To make his defeat more ignominious, the cap had stuck 

 in a thorn bush, from which the little biped did not recover it 

 without sundry pricks and provoking scratches. Wo rejoiced 

 in the escape of the insect, knowing well that its hunter did not 

 wish to examine the wonders of that tiny " thing of life," but to 

 gratify his bump of destructiveness. 



Now we are not going to write the history and adventures of 

 that particular butterfly ; we are not certain that we ever saw 

 this particular insect again, but wish to make a few remarks 

 on his relations and friends. In summer they are glancing hither 

 and thither over meads and gardens, and we cannot let such 

 beauties pass unnoticed. 



It seems almost an insult to call such a brightly-robed creature 

 an insect, but we must not flatter the proudest butterfly, merely 

 because he wears a fine coat. How vast seems the difference 

 between the abhorred cockroach and the splendid peacock butter- 

 fly ! yet the latter cannot deny his distant relationship to that 

 creeping thing, hated by all housemaids : both are insects. A 

 long Greek name separates the princes of the insect world from 

 the less honoured orders. Lepidoptera (a term meaning scale- 

 winged) is the title of nobility applied by the great Swedish 

 historian of the animal kingdom, Linnasus, to the butterflies 

 and moths. We must pass over the latter for the present, and 

 confine our attention to their less numerous but more admired 

 relations. 



The term "butterfly" seems to be unsuitable for an insect 

 which has a taste far too refined for butter. The name was, it 

 is thought, given to the insect by our Saxon ancestors, because it 

 appeared in the butter-making season. Be it so ; many a finer 

 name has had a lower origin. Has the butterfly a memory P If 

 so, does the insect recollect the two previous states through 

 which it has passed ? Perhaps not ; but we must not forget the 

 former condition of our brilliant white admiral, or swallow-tail. 

 First a caterpillar ; then cramped in bands and folds, which we 

 call a chrysalis ; and, lastly, a winged fairy of the air. Catch 

 that large "White Cabbage," lady butterfly (Pontia Brassicce), 

 and ask her a few questions about " auld lang syne," just to 

 illustrate what are called metamorphoses. 



On the 1st of May last year we like to be particular in 

 dates her grandmother was a bandaged chrysalis, and about 

 the end of the month became a butterfly. Her elegantly-shaped 

 eggs were carefully laid on the under side of nicely-selected 

 cabbage leaves, without permission of the gardener. Mighty 

 was his rage when, in a few days, his choicest cabbages were 

 sawn into the most intricate patterns by a thriving family 

 of ravenous caterpillars. To kill them all was out of the ques- 

 tion. Napoleon's artillery might have failed to accomplish that. 

 Many did perish; the sparrows especially delighted in such 

 delicious morsels. One, however, escaped, in consequence of her 

 exceeding cleverness in feeding on leaves concealed from the 

 birds' eyes. Having formed a chrysalis, she secured the cradle- 

 like bit of work to a sunny wall by a strong but elegant silken 

 band. 



From this came a butterfly about August, the mother of the one 

 which is supposed to have been just caught by the reader. From 

 her eggs sprang another succession of caterpillars, which changed 

 to chrysalides in September last. Now mark what followed. 



The term Papilio is applied to a large butterfly family ; Macliaon is 

 the name of a famous physician present at the siege of Troy, and desig- 

 nates this particular species. 



