118 



♦ KNOWLEDGE ♦ 



[Aug. 8, 1884. 



" I know not," said I ; "but I am sure Copernicus him- 

 self distrusted the success of his opinion. He was a long 

 time before he would venture to publish it, nor had he done 

 it then without the importunity of his friends. Uut do 

 you know what became of him 1 The very day they brought 

 him the first printed sheet of his book he died. He fore- 

 saw he should never be able to reconcile all the contradic- 

 tions, and, therefore, very wisely slipt out of the way." 



"1 would be just to all the world," said the Mar- 

 chioness, " but 'tis hai-d to fancy we move and yet see we 

 do not change our place. We find ourselves in the morning 

 where we lay down at night. Perhaps you will tell me the 

 whole earth moves." 



" Yes, certainly," said I ; " it is the same case as if you 

 fell asleep in a boat upon the river, when you awake you 

 find yourself in the same place and the same situation in 

 respect to all the parts of the boat." 



" 'Tis true," she reply 'd ; " but here's a great difference; 

 when I awake I find another shore, and tliat shews me my 

 boat hath changed place ; but 'tis not the same with the 

 earth. I find all things as I left 'em." 



" No, no," said I ; " there is another shore too. You 

 know that beyond the circles of the planets are fixed stars ; 

 there is our shore. 1 am upon the earth, and the earth 

 makes a great circle round the sun. I look for the centre 

 of the circle, and see the sun there ; then I direct 

 my sight beyond the sun in a right line, and should 

 certainly discover the fixed stars which answer to the 

 oun, but that the light of the sun eflaces 'em. But at 

 night I easily perceive the stars which correspond with 

 him in the day, which is exactly the same thing ; if the 

 earth did not change its place in the circle where it is, I 

 -should see the sun always against the same fixed stars ; but 

 when the earth does change its place, the sun must answer 

 to other stars ; and there again is your shore, which is 

 always changing. And seeing the earth makes her circle 

 in a year, I see the sun likewise in the space of a year 

 answer successively to the whole circle of the fixed stars, 

 which circle is called the Zodiac. I will draw you the figure 

 of it, if you please, on the sand." 



"'Tis no matter," said she. " I can do well enough with- 

 out it ; besides, it will give an air of learning to my park, 

 which I would not have in it. For I have heard of a 

 certain philosopher, who, being shipwreck'd and cast upon 

 an uuknown island, seeing several mathematical figures 

 traced on the sea-shore, cry'd out to those that followed 

 him, 'Courage, my companions, the isle is inhabited ; behold 

 the footsteps of men : ' but you may spare your figures ; 

 such footsteps are not decent here." 



"I confess, madam," said I, "the footsteps of lovers would 

 better become this place ; that is, your name and cypher 

 icarv'd on the trees by your adorers." 



"Tell not me," said she, "of lovers and adorers; I 

 am for my beloved sun and planets. But how comes it 

 to pass that the sun, as to the fixed stars, compleats his 

 course but in a year, and yet goes over our heads every 

 day." 



" Did you never," reply'd I, " observe a bowl on the 

 Green t It runs towards the Jack, and at the same time 

 turns very often round itself, so that the parts which were 

 above are below, and those which were below are above ; 

 just 60 it is with the earth, at the same time that she ad- 

 vances on the circle, which in a year's space she makes 

 round the sun, in twenty-four hours she turns round herself; 

 80 that in twenty-four hours every part of the earth loses 

 the sun,* and recovers him again, and as it turns towards 



* ThiB, of conrse, is inexact ; being only true at the time of the 

 vernal or autumnal equinox. But it is nearly true of the habitable 

 parts of the earth. — R. P. 



the sun, it seems to rise ; and as it turns from him, it seems 

 to fall." 



"It is very pleasant," said she, "that the earth must 

 take all upon herself, and the sun do nnthing. And when 

 the moon, the other planets, and the fixed stars seem to go 

 over our heads every twenty-four hours, yoti'll say that, too, 

 is only fancy ?" 



" Mere fancy," said I, " which proceeds from the same 

 cause ; for the planets compleat their courses round the sun 

 at unequal times, according to their unequal distances ; and 

 that which we see to day answers to a certain point of the 

 Zodiac, or circle of the fixed stars, we see to-morrow answer 

 to another point, because it is advanced on its own circle, as 

 well as we are advanced upon ours. We move, and the 

 planets move too, which must make a great alteration ; so 

 that what seems irregular in the planets, proceeds only 

 from our motion, when, in truth, they are all very regular." 



" I will suppose 'em so," said the Marchioness ; " but I 

 would not have their regularity put the earth to so great 

 trouble ; methinks you exact too much activity from so 

 ponderous a mass." 



" But," said I, " had you rather that the sun and all the 

 stars, which are vast great liodies, should in twenty-four 

 hours travel such an infinity of milec, and make so pro- 

 digious a tour as they needs must, if the earth did not turn 

 round itself every twenty-four hours'?" 



" Oh," said she, " the sun and the stars are all fire, their 

 motion is not very diflS^cult ; but the earth, I fancy, is a 

 little unwieldy." 



" That signifies nothing," I replied ; " for what do you 

 think of a first rate ship, which carries near 150 guns, and 

 above 3,000 men, besides great loads of merchandise? yet 

 you see one puff of wind sets her a-sailing, because the 

 water is liquid, and, being easily separated, very little 

 resists the motion of the ship. So the earth, though never 

 so weighty, is as easily borne up by the celestial matter, 

 which is a thousand times more fluid than the water,* and 

 fills all that great space where the planets float ; for where 

 would you have the eatth fastened to resist the motion of 

 the celestial matter, and not be driven by it 1 You may as 

 well fancy a little block of wood can withstand the current 

 of a river." 



THE INTERNATIONAL HEALTH 

 EXHIBITION. 



XL— WATER AND WATER-SUPPLIES— (confinued). 



TTTE have now placed before our readers the chief types 

 \* of water that are commonly derived from both 

 natural and artificial sources. It yet remains to be seen 

 whether any of those crude product.s are directly available, 

 and how we are to deal with such as are not so, in order to 

 render them fit for domestic purposes, and valuable in 

 various industries and arts. 



In the household, the water in this, and all countries with 

 temperate climates, is derived from many different origins. 

 In considering the problem before us, we shall take, as an 

 example, a model tenement provided with every possible 

 convenience and variety of supply ; we shall then be able 

 to indicate how the wants of special cases are to be pro- 

 vided for by referring to s-ome particular section of our 

 hypothetically perfect mansion. Imagine, too, that to this 

 abode there is attached a series of typical workshops, each 

 concerned with some special manufacturing process, and 

 that the entire system is furnished with (1) winter re- 

 servoirs for the utilisation of snow and ice ; (2) tanks for 



* AH the reasoning here relates to the system of Vortices. — 

 R. P. 



