corresponding to its temperature. Let us contrast its action with that of air coming to Hind Head from a quarter less competent to charge it with aqueous vapour. We were visited by such air on the 10th of last December, when the movement of the wind was light from the north-east, the temperature at the time being very low, and hence calculated to lessen the quantity of atmospheric vapour. Snow a foot deep covered the heather. At 8.5 A.M. the two thermometers were taken from the hut, having a common temperature of 35°. The one was rapidly suspended in the air, and the other laid upon the wool. I was not prepared for the result. A single minute's exposure sufficed to establish a difference of 5° between the thermometers; an exposure of five minutes produced a difference of 13°; while after ten minutes' exposure the difference was found to be no less than 17°. Here follow some of the observations :—

December 10.-Deep snow; low temperature; sky clear; light

north-easterly air.

Wool.

Time.

A.M.

8.10

8.15

8.20

8.30

8.40

8.45

8.50

Air.

Difference.

O

13

17

15

15

16

16

18

During these observations, a dense bank of cloud on the opposite ridge of Blackdown virtually retarded the rising of the suu. It had, however, cleared the bank during the last two observations, and, touching the air thermometer with its warmth, raised the temperature from 26° to 27° and 29°. The very large difference of 18° is in part to be ascribed to this raising of the temperature of the air thermometer. I will limit myself to citing one other case of a similar kind. On the evening of the 31st of March, though the surface temperature was far below the dew point, very little dew was deposited. The air was obviously a dry air. The sky was perfectly cloudless, while the barely perceptible movement of the air was from the north-east. At 10 P.M. the temperature of the air thermometer was 37°, that of the wool thermometer being 20°, a refrigeration of 17° being therefore observed on this occasion..

From the behaviour of a smooth ball when urged in succession over short grass, over a gravel walk, over a boarded floor, and over ice, it has been inferred that, were friction entirely withdrawn, we should have no retardation. In a similar way, when under atmospheric condi

tions visibly the same, we observe that the refrigeration of the earth's surface at night markedly increases with the dryness of the atmosphere, we may infer what would occur if the invisible atmospheric vapour were entirely withdrawn. I am far from saying that the body of the atmosphere exerts no action whatever upon the waves of terrestrial heat; but only that its action is so small that, when due precautions are taken to have the air pure and dry, laboratory experiments fail to reveal any action. Without its vaporous screen, our solid earth would practically be in the presence of stellar space; and with that space, so long as a difference existed between them, the earth would continue to exchange temperatures. The final result of such a process may be surmised. If carried far enough, it would infallibly extinguish the life of our planet.

CAIRO: THE OLD IN THE NEW.

I.

N the present paper I shall consider Cairo as the parent city of

ancient and the most ancient of all. It is no part of my aim to describe the wonderful charm of this remarkable city. She, the precious diamond in the handle of the green fan of the Delta, has been celebrated in song and flowing prose both by the East and by the West. The delightful poet, Beha-ed-din Zoher, who lived at the Court of Cairo as Secretary to the Sultan Melik-eç-Calech, a grandnephew of Saladin's, is never weary of celebrating in animated verses the picturesqueness of the place, the power of her princes, the beauty of her women, the charming mildness of her nights, which brought soft dreams to the heart of the poet when he was alone, and which he had often passed happily right on till morning in garden parties, Nile trips, and drinking bouts with bands of merry friends. In the "Thousand and One Nights," many a dwelling-place of mortal men is invested, by the transfiguring power of the imagination of the narrator, with an inconceivable and more than earthly glory, but none of all these pearls shines with a purer water or is counted rarer and more beautiful than Cairo. The oldest of the interlocutors-i.e., the one who had seen most and whose judgment is of most value, speaks in these enthusiastic words: "He who has not seen Cairo has not seen the world. Its earth is gold, its women are bewitching, and its Nile is a wonder." night Scheherezade praises the charms of the city of the Pyramids in these terms: "As compared with a sight of this city, what is the joy of setting eyes on your beloved! He who has seen it will confess that there exists for the eye no higher enjoyment, and when one remembers the night on which the Nile comes to its height, he gives back

On the following

the wine-cup to the bearer full, and makes water flow up to its source again." That is as much as to say, there is nothing more left that he can do. And to the interlocutors in these tales Cairo was no picturein a dream, no inaccessible island of the blest, no distant Golconda, for there is no manner of doubt that it was in the very Cairo we see, and‹ in the time of the Mameluke Sultan El-Ghuri that this treasure of old Moslem tales, which has for centuries circulated in small gold pieces from hand to hand, from people to people, was originally collected and minted into those very forms in which they are at this hour familiar to all the nations of the earth. God has granted to the writer of these lines the favour of sending him into the wide world). and letting him wander over land and ocean, and see many towns and countries; but when he now travels backwards in thought, and sweeps over the whole realm of recollection lying behind him, he discovers no city on the face of the earth that seems to him more · charming than Cairo.

The tourist who visits the place, without previous preparation, under the guidance of a tour-contractor, is as unable to escape its charm as the scholar who is familiar with every phase of its development and with every movement of its life. The artist finds himself embarrassed with the abundance of the materials and the richness of the colourswhich surround him, and for the musing dreamer, the looker-on at the play of life, there is no more favourable spot than this. To. open the eyes means here to receive new impressions, to look about is to learn, and stimulated by the abundance of picturesque forms and scenes, even the most indolent feels himself compelled to be always viewing things. For the investigator, who is permitted to touch with the hand the thing he has brought with him to the Nile as a mental possession, other enjoyments still are always in store in Cairo. We children of northern cities would be repaid by a journey to the Nile, were it by nothing else than breathing on a clear winter morning the pure spicy air of the desert, or seeing from the citadel on a fine evening the sun go down behind the Pyramids, and the cupolas and minarets of the town glittering in airy robes of rose and violet, and finally sinking under the dark shroud of night.

Who has joined in the crowd at the bazaars, who has allowed the venerable monuments of the time of the Pharaohs to work upon his mind, and has regretted his decision of visiting Egypt? The advice to make a pilgrimage to Cairo is good advice, and the sooner one follows it the better; for the city of the Caliphs is already far from being what it was a few lustra ago, when it was first our privilege to visit it; and if we remain another decade in the country, we shall see · similarly disappear one feature after another of all that to-day gives the place its special charm. The more firmly Western influence establishes itself in Egypt, the more sensibly do its assimilating power

and the sober practical sense of utility characteristic of our civilization make their presence apparent. What grows organically among us is transplanted right off into this foreign soil and starts up quite remarkably. It is oftentimes like uprooting the palms of the Nile and planting firs and apple-trees in their place. The absurdity of many of the improvements every one has felt who has formerly walked under the shadow of the houses in the narrow lanes of Cairo, and now finds himself in broad squares and wide streets completely unprotected from the fiery darts of the sun of the south. This change is lamented by every traveller who has seen, in other days, riders, carriages, camels, and foot-passengers passing like a full stream over the soft roadway of the Muski, with many a call and cry, but without either rustle or tramp or clatter, and who has now his word drowned at his mouth by the deafening din of wheels, hoofs, and footsteps that rises from the glowing pavement. The shade-dispensing boards and awnings which in many places covered the most frequented streets of the town have been removed, because such things are not to be found in any Western metropolis. In the dwellings of the well-to-do Egyptians, European furniture has supplanted the native outfitting of the rooms, which is so picturesque and which originated in its suitability to the manners and customs of the Moslems. Imagine a bearded turban-wearer sitting cross-legged, not on a broad divan, but on a Paris or Vienna armchair! Gone, too, is the old arrangement of the dwelling-house, so well suited at once to the Egyptian climate and to the peculiarities of the Moslem family. He who builds now wishes to build cheaply and rapidly, and in a sort of European style, and so, from never being considered, the wonderful art of the mason, which delights the connoisseur in many of the older houses, has been entirely lost. The picturesque lattice-windows of the Meschrebijen, whose thousand finely moulded pieces seem like a veil of woven wood before the women, enabling them to see everything doing in the streets without themselves being seen, are now, in many cases, replaced by the Venetian blinds of Europe. Fine examples of the old lattice-work find ready purchasers, and they may be often enough met with in rooms fitted out in Arabian style in England, France, and Germany. The same is true of the Kursis, desks, posts, and doors, inlaid with ivory, mother-of-pearl, and various woods; and ancient implements are very eagerly sought after by collectors of art and antiquities. In my library stand two old Arabian jugs, which Frank Dillon, of London, the excellent painter of Oriental landscapes and architecture, found in an oil-ship, with twelve others, and bought for an old song. I saw an American family send whole shipfuls of old Arabian ware to the New World, and I know that not less than seventy finely executed old fauns from one of the most famous mosques were sold right off to tourists.