Page:Popular Science Monthly Volume 54.djvu/739

Rh, and as far as the Bermudas, 10.11 miles; from the Bermudas to the Azores, 6.42 miles. The mean speed for the North Atlantic was 4.48 miles. The figures are under rather than above the truth.

Winds of the Sahara.—Some interesting meteorological observations, made in the Sahara during eight excursions between 1883 and 1896, have been published by M. F. Foureau. The most frequent winds are those from the northwest and the southeast. Every evening the wind goes down with the sun, or goes to bed, as the Chaambe express it; except the northeast wind, which the Arabs call el chitâne, or the devil, because it blows all night. Another wind, called the chihithi, has been mentioned by all travelers, and is the subject of numerous legends. It is a warm wind from the southwest, charged with electricity, and often carrying fine sand and darkening the atmosphere. The compasses are much disturbed by it, because, it has been suggested, of a special condition produced upon thin glass covers by the friction caused by the rubbing of the fine wind-carried sand upon them; but it has been observed that the spare compasses show the same disturbed condition as soon as they are taken out of their boxes. The disturbance ceases when the glasses are moistened, and does not appear again till they have dried. Several hailstorms were noticed, the hailstones being usually about as large as peas, but larger in the heavier storms. M. Foureau, not having gone as far as the central heights, observed no snow in the Sahara, but was informed that snow falls in the winter on the tops of the Tassili des Azdjer, about five thousand feet above the sea. Similar observations have been made by other travelers, and falls of temperature to about 21° F. have been noticed. Very curious mirage phenomena were sometimes observed. Observations of fulgurites, or instances in which the sand had been vitrified by lightning strokes, were not infrequent.

Evolution of Pleasure Gardens.—A lesson in the evolution of pleasure resorts is suggested in a book by Mr. Warwick Wroth on the London pleasure gardens. The history of these places has in some cases a strong family resemblance. They usually began as tea gardens, with a bowling green, tea and coffee, hot loaves, and milk "fresh from the cow," as their chief attractions. If the business prospered, other amusements were added, such as music and dancing, with perhaps the exhibition of a giant or a fat woman. Equestrian performances were given in the more important gardens. The manager of one of them kept on the grounds a fine collection of rattlesnakes, one having nineteen rattles and "seven young ones." "Sixteen hundred visitors were present at another one day in August, 1744, to hear honest 'Jo Baker' beat a trevally on his side-drum as he did before the great Duke of Marlborough at the bloody battle of Malplaquet. It was not unusual, moreover, for the owner of a successful tavern to discover on his premises a mineral spring, of which a favorable analysis was easily obtained"—although the spring might be really a bad one. The Spa of Hampstead Wells enjoyed a delightfully pure and invigorating air on the open heath, and had a tavern with coffee rooms, a bowling green, raffling shops, and a chapel, which offered visitors an advantage possessed by no other gardens in London, as a clergyman was always in attendance, and a couple on presenting a license could be married at once on the payment of five shillings. Mr. Wroth suggests that the license was sometimes dispensed with, and the fee, moreover, was remitted if the wedded pair gave a dinner in the gardens.

A Library of Astronomical Photographs.—The appointment of Mrs. M. P. Fleming as curator of astronomical photographs in the Harvard Observatory is noteworthy because hers is the first woman's name to be placed along with the officers in the university catalogue. It is more so as a recognition of Mrs. Fleming's proved abilities in certain lines of astronomical work. The astrophotographic building is not used for the taking of photographs, but as a peculiar kind of library where the plates secured by the astronomers at Cambridge and Arequipa are preserved, arranged, and catalogued, as is done with books. The duties of the curator are like those of a librarian. But instead of books, of which many copies exist, each of the treasures in the photographic collection is unique and can not be duplicated. Prints