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the optic nerve springs, makes no impression; and therefore,
1 if the picture of an object falls thereon, it is not perceivel, and that object is invisible. This will appear by placing a small bright object before you, and looking at it with one eye:
: then moving one eye laterally towards the contrary side (towards the left, if it be the right eye), the object will disappear, and seem to be lost ; and moving it still farther, it will
re-appear. This place is not however at the bottom of the eye, but nearer the nose in both of them ; so that no rays, either parallel or diverging, that come from any object, can fall upon that place in both the eyes; so that any object we direct the eyes to, will always be visible, at least to one eye. But the same bright object may be made to disappear to both eyes, by directing the axes of both eyes to a point a little beyond the nose, to be found by trials.
“ Dimness of sight generally attends old people, and it may arise from either of these two causes :
By the eyes growing flat, and not uniting the rays at the retina, which causes indistinctness of vision; or,
“ By the opacity of the humours of the eye, which, in time, lose their transparency in some degree; from whence it follows, that a great deal of the light that enters the eye, is stopt and lost ; and every object appears faint and dim.
“ As the rays of light flowing from an object, and painting its image upon the retina, are the immediate cause of seeing ; so where there is no light, there can be no vision : consequently without light, the eye becomes a machine ut. terly useless; as it can give us no manner of information of the existence of bodies at a distance from us.
“ People's different length of sight is owing to a more or less convexity of the cornea and crystalline humour of the eye: the rounder these are, the nearer will be focus or point of the meeting rays, and so much the nearer must an object be brought to see it well. The case of short-sighted people is only an over-roindness of the eye, which makes a very near focus; and that of old people is a sinking or flattening of the eye, whereby the focus is thrown to a great distance; hence the former may properly be called eyes of too short, and the latter eyes of too long, a focus. The remedy for the last is a convex
glass, to supply the want of convexity in the eye itself, and bring the rays to a shorter focus ; but the first require a concave glass, to scatter the rays, and prevent them coming to a point too soon.
“ Nothing is more common, than to observe old people holding objects which they would examine, at a great distance from them, for the reason above-mentioned ; and every one knows, that short-sighted people cannot distinguish an object without bringing it very near to their eyes. Both extremes are very inconvenient; but those whose eyes are flat by age, should remember with satisfaction, that they have enjoyed the pleasure of them for many years ; and the shortsighted may comfort themselves, that they can distinguish much smaller objects than long-sighted people ; for the object is magnified in proportion to the roundness of the eye and the nearness of the focus, and consequently appears four times as big to an eye whose focus is but four inches off, as it does to one whose focal distance is at eight inches. Shortsighted people have also this farther advantage, that age im. proves their eyes, by the same means that it impairs other people's, that is, by making them more flat.
" The nearer any object can be brought to the eye, the the larger will the angle under which it appears, and the more it will be magnified. 6. Now that distance from the naked
where the generality of people are supposed to see small objects best, is about six inches; consequently, when such objects are brought nearer than this measure, they will become less distinct; and if they are brought to four or three inches, they will scarce be seen at all. But by the help of convex glasses, we are enabled to view things clearly at much shorter dis. tances than these; for it is the nature of a convex lens, to render an object distinctly visible to the eye, at the distance of its focus ; wherefore, the smaller a lens is, and the more its convexity, the nearer is its focus, and the more its magnifying power.
“ When yiasses are put in frames for spectacles, these frames ought not to be straight, to place both eyes in the same plane, but they should be so bent in the middle, that the axes of both glasses may be directed to one point, at such a distance as you generally look with spectacles. By this means the eye will fall perpendicular upon both glasses, and make the object appear distinct: but if they fall obliquely upon the glasses, this obliquity will give a confused appearance to the objects to which the eyes are directed."
EDWARD.-" The best spectacles are made from the Brazilian pebble; are they not?”
Dr. Walker, " Yes.
. “ Thus much for the eye and its wonderful properties; and now, Edward, to bed, where for a tine that precious sense will, I hope, soon be soothed to a transitory state of insensibility. To morrow you know we visit Twer.”
Upon arriving at the elegant city of Twer, formerly the residence of the ancient dukes of Russia, they regaled themselves upon a delicious fish called Sterlets, which are caught in the river Wolga. After dinner they strolled through the town, which stands at the confluence of the Twerza and the Wolga, and which suffered by conflagration in 1763. It is rebuilt on a plan suggested by the empress, who advanced about 60,0001. ; in shares of about 3001. each, to those who erected brick houses : she had a little after generously remitted one half of the debt, and founded a school for the instruction of 200 pupils. Here is also a seminary that admits 600 students, and an academy for 120 of the nobility. This town is commercial, and is the thoroughfare for all the merchandize sent by water from Siberia and the southern provinces to Petersburg, and bids fair to rival the finest provin. cial cities of Europe. Provisions are extremely cheap here, and the inhabitants enjoy most of the luxuries of life in great profusion. It however contains nothing extraordinarily curious, to arrest a traveller's notice; although it presents many allurements to those who are anxious to find a comfortable place of residence.
Dr. Walker, therefore, and his pupil, proceeded on the following day to Torshok, and from thence to Moscow.
«« Moscow is like a phenix,” said the Doctor, as they entered the city,
“it is rising from its ashes.” EDWARD. .“ Was it not strange, Sir, that the ancients should give such implicit credence to the fable of the Phænix?”
Dr. Walker.-" Yes. But that it was formerly believed by them, we have the authority of Herodotus. You recollect what he says upon the subject ?"
EDWARD.-- Yes, Sir. He says that there was never 'but one at the same time, and that he was brought forth in Arabia; that he lived five or six hundred years, and was of the size of an eagle. His head was adorned with a shining crest, the feathers of the neck were of a beautiful gold colour, and the rest of his body was purple ; his tail was white intermixed with red, and his eyes sparkling like stars. When he was old, and found his end approaching, he built a nest with wood and aromatic spices, and then died. Of his bones and marrow, a worm was produced, out of which another Phænix is formed. His first care was to solemnize his parents obsequies, for which purpose he made up a ball, in the shape of an egg, with abundance of perfumes of myrrrh, as heavy as he could carry, which he often essayed beforehand; then he made a hole in it, in which he deposited his parent's body, closing it carefully up with myrrh and other perfumes. After this he took up the precious load on his shoulders, and flying to the altar of the sun, at Heliopolis, he there burnt it."
On the following morning Dr. Walker, and his young friend visited the Foundling-Hospital, which was founded by the empress Catherine II. and is supported by voluntary contributions, legacies, and other charitable endowments. It is an immense quadrangular building, and is calculated to accommodate upwards of 8000 foundlings. These children are well brought up, and at the age of fourteen, they are permitted to chuse a trade, and at twenty they leave the hospital, and have the peculiar privilege of setting up in business in any part of Russia, a sum of money being given them for that purpose.
The Kremlin is one of the most extensive palaces in the world. It contains a palace, a cathedral with nine towers covered with copper doubly gilt, five convents, four parish churches, their spires richly gilt, an arsenal, and several other public buildings. The Russians are passionately fond of bells; and few actions indicate so much piety as the gift of a stupendous bell." The English, you know, Edward, are as
“ celebrated for their love of bells as the Russians; but the difference between the two partialities is this, the size of the bell constitutes its beauty and merit in the dominions of Alexander, while in England it is its musical property, which enhances its value. The English are said to have reduced bell-ringing to a science.” The Moskwa, from which Moscow takes its name, is a small stream, navigable in the summer for boats only. The style in which Moscow is rebuilding, is very much in its former style. Lai ge and small houses stand side by side, and present a motley appearance of poverty and splendour. When Buonaparte and his destructive army entered Moscow, after having stripped the principal houses, they battered the shells down with cannon, and even broke open the tombs of the dead to find treasure. The rage of the French emperor when he found the inhabitants had set fire to their houses, thus vented itself upon
the possessions of those whose property had escaped that all devouring element.”
Upon passing through some of the suburbs of the city, our travellers were surprised at the paucity of the population in this immense town; upon mentioning this circumstance to their host, he smiled, and bade them take such a direc. tion, and they would find people enough. They immediately directed their steps to the quarter he pointed out, and were amply gratified with the curious and novel spectacle which presented itself to their observation. Greeks, Turks, Poles, Cossacks, Chinese, French, Italians, Germans, in short inhabitants from every part of Europe and Asia were here as sembled, all habited in their respective costumes. “ This is a perfect masquerade," observed Doctor Walker, as they forced their way through the busy crowd, “ where, if each of the different characters could divest hiinself of his interested pursuits, so far as to be able to comment upon those who surround him, what various remarks we should hear. Look at those Kirgissians with their bald heads covered with conical embroidered caps, and their sheep skins as garments; observe those Chinese, and those wild Bucharians; to them we appear equally extraordinary as they do to us, and their contempt of our smart broad-cloth, had they leisure to express it, would perhaps excite our risibility, not our indignation. There we have the advantage over them. We have seen too much of mankind, and traversed too many different countries to feel hurt at the observations of those who are not like us citizens of the world. But come, Edward, let us take a view of the amusements of these good people. I see a crowd assembled a short distance from this exchange, who are engaged with no less zeal in the pursuit of pleasure, than those who surround us, where business gives an air of such importance to every countenance. I fear we must be but spectators, not actors in this animated scene, continued the