system have, respectively, diameters of 34 in. and 29 in. These two magnificent objectives and the two mirrors were constructed by the Brothers Henry, whose double reputation as astronomers and opticians is so universally established. The mechanical part is the successful work of Mr. Gautier, who has looked after every detail with the greatest care, and has thus realized a true chef d'oeuvre. The colossal instrument, the total weight of which is 26,400 lb., is maneuvered by hand with the greatest ease. A clockwork movement, due to the same able manufacturer, is capable, besides, of moving the instrument with all the precision desirable, and of permitting it to follow the stars in their travel across the heavens. A star appearing in the horizon can thus be observed from its rising to its setting. The astronomer, his eye at the ocular, is always conveniently seated at the same place, observing the distant worlds, rendered immovable, so to speak, in the field of the instrument. For stars which, like the moon and the planets, have a course different from the diurnal motion, it is possible to modify the running of the clockwork, so that they can thus be as easily followed as in the preceding case. Fig. 1 gives a general view of the new installation, for which it became necessary to build a special edifice 65 ft. in height on the ground south of the observatory bordering on the Arago Boulevard. A large movable structure serves for covering the external part of the instrument. This structure rests on rails, upon which it slides toward the south when it is desired to make observations. It will be seen from the figure how the principal axis of the instrument rests upon the two masonry pillars, one of which is 49 ft. and the other 13 ft. in height.

FIG 1.—THE GREAT EQUATORIAL OF THE PARIS OBSERVATORY.

The total cost of the pavilion, rolling structure, and instrument (including the two objectives) will amount to about $80,000 after the new equatorial has been provided with the scientific apparatus that necessarily have to accompany it for the various and numerous applications to which the use of it will give rise.

FIG 2.—OCULAR OF THE GREAT EQUATORIAL.

Fig. 2 shows us the room in the observatory in which the astronomer, seated in his chair, is completely protected against the inclemencies of the weather. Here, with his eye applied to the ocular, he can, without changing position (owing to all the handles that act at his will upon the many transmissions necessary for the maneuvering), direct his instrument unaided toward every point of the heavens with wonderful sureness and precision. The observer has before him on the same plane two divided circles, one of which gives the right ascensions and the other the declinations, and which he consults at each observation for the exact orientation of the equatorial.

All the readings are done by the aid of electric lamps of very small dimensions, supplied by accumulators, and which are lighted at will. Each of these lamps is of one candle power; two of them are designed for the reading of the two circles of right ascension and of declination; a third serves for the reading of the position circle of the micrometer; two others are employed for the reading of the drums fixed upon the micrometric screws; four others serve for rendering the spider threads of the reticule brilliant upon a black ground; and still another serves for illuminating the field of the instrument where the same threads remain black upon a luminous ground. The currents that supply these lamps are brought over two different circuits, in which are interposed rheostats that permit of graduating the intensity of the light at will.

Since the installation of the first model of an elbowed equatorial of 11 in. aperture, in 1882, at the Paris Observatory, the numerous and indisputable advantages of this sort of instrument have led a certain number of observatories to have similar, but larger, instruments constructed. In France, the observatories of Alger, Besancon, and Lyons have telescopes of this kind, the objectives of which have diameters of from 12 in. to 13 in., and which have been used for several years past in equatorial observations of all kinds. The Vienna Observatory has for the last two years been using an instrument of this kind whose objective has an aperture of 15 inches. Another equatorial of the same kind, of 16 in. aperture, is now in course of construction for the Nice Observatory, where it will be especially employed as a seeker of exceptional power—a role to which this kind of instrument lends itself admirably. The optical part of all these instruments was furnished by the Messrs. Henry, and the mechanical part by Mr. Gautier.

The largest elbowed equatorial is, therefore, that of the Paris Observatory. Its optical power, moreover, corresponds perfectly to its huge dimensions. The experimental observations which have already been made with it fully justify the hopes that we had a right to found upon the professional skill of the eminent artists to whom we owe this colossal instrument. The images of the stars were given with the greatest sharpness, and it was possible to study the details of the surface of the moon and other planets, and several star clusters, in all their peculiarities, in the most remarkable manner.

When it shall become possible to make use of this equatorial for celestial photography, there is no doubt that we shall obtain the most important results. As regards the moon, in particular, the photographing of which has already made so great progress, its direct image at the focus of the large 24 in. photographic objective will have a diameter of 11 in., and, being magnified, will be capable of giving images of more than 3 ft. in diameter.—La Nature.

LILY OF THE VALLEY.

There is no flower more truly and universally popular than the lily of the valley. What can be more delicious and refreshing than the scent of its fragrant flowers? What other plant can equal in spring the attractiveness of its pillars of pure white bells half hidden in their beautiful foliage? There are few gardens without a bed of lily of the valley, but too often the place chosen for it is some dark corner where nothing else would be expected to grow, but it is supposed as a matter of course that "it will do for a lily bed." The consequence is that although these lilies are very easy things to cultivate, as indeed they ought to be, seeing that they grow wild in the woods of this and other countries, yet one hears so often from those who take only a slight interest in practical gardening, "I have a lily bed, but I scarcely ever get any lilies." Wild lilies are hardly worth the trouble of gathering, they are so thin and poor; it is interesting to find a plant so beautiful and precious in the garden growing wild in the woods, but beyond that the flowers themselves are worth but very little. This at once tells us an evident fact about the lily of the valley, viz., that it does require cultivation. It is not a thing to be left alone in a dark and dreary corner to take care of itself anyhow year after year. People who treat it so deserve to be disappointed when in May they go to the lily bed and find plenty of leaves, but no flowers, or, if any, a few poor, weak attempts at producing blossoms, which ought to be so beautiful and fragrant. One great advantage of this lovely spring flower is that it can be so readily and easily forced. Gardeners in large places usually spend several pounds in the purchase of crowns and clumps of the lily of the valley, which they either