The Hampshire Down breed of sheep originated about 80 years ago by a cross of South Downs on the horned, white-faced sheep which had for ages been native of the open, untilled, hilly stretch of land known as the Hampshire Downs, in the county of that name bordering on the English Channel, in the South of England. From time immemorial the South Downs had dark brown or black legs, matured early, produced the best of mutton and a fine quality of medium wool. The original Hampshire was larger, coarser, but hardier, slower to mature, with inferior flesh, and a longer but coarser wool. The South Down has always been remarkable for its power of transmitting its special characteristics to its progeny by other kinds of sheep, and hence it soon impressed its own characteristics on its progeny by the Hampshire. The horns of the original breed have disappeared; the face and legs have become dark, the frame has become more compact, the bones smaller, the back broader and straighter, the legs shorter, and the flesh and wool of better quality, while the superior hardiness and greater size, as well as the large head and Roman nose of the old breed, still remain. The Hampshires of to-day mature early and fatten readily. They clip from six to seven pounds of wool, suitable for combing, which is longer than South Down wool, but less fine. The mutton has a desirable proportion of fat and lean, and is juicy and fine flavored. The lambs are of large size and are usually dropped early and fed for market. Indeed, the Hampshire may be considered a larger and trifle coarser and hardier South Down. The breed is occasionally crossed with Cotswolds, when it produces a wool more valuable for worsted manufacturers than the pure Cotswold. Indeed, there is little doubt that in addition to South Down, the Hampshire has a dash of Cotswold blood in its composition. Considerable importations of the breed have been made into this country, but it has not become so popular as the South Down and some other English breeds. The excellent group shown is owned by Mr. James Wood, of Mount Kisco, New York.—Rural New-Yorker.
THE YALE COLLEGE MEASUREMENT OF THE PLEIADES.[1]
The Messrs. Repsold have established, and for the present seem likely to maintain, a practical monopoly in the construction of heliometers. That completed by them for the observatory of Yale College in 1882 leaves so little to be desired as to show excellence not to be the exclusive result of competition. In mere size it does not indeed take the highest rank. Its aperture is of only six inches, while that of the Oxford heliometer is of seven and a half; but the perfection of the arrangements adapting it to the twofold function of equatorial and micrometer stamps it as a model not easy to be surpassed. Steel has been almost exclusively used in the mounting. Recommended as the material for the objective cell by its quality of changing volume under variations of temperature nearly paripassu with glass, its employment was extended to the telescope tube and other portions of the mechanism. The optical part of the work was done by Merz, Alvan Clark having declined the responsibility of dividing the object lens. Its segments are separable to the extent of 2°, and through the contrivance of cylindrical slides (originally suggested by Bessel) perfect definition is preserved in all positions, giving a range of accurate measurement just six times that with a filar micrometer. (Gill, "Encyc. Brit.," vol. xvi., p. 253; Fischer, Sirius, vol. xvii., p. 145.)
This beautiful engine of research was in 1883 placed in the already practiced and skillful hands of Dr. Elkin. He lost no time in fixing upon a task suited both to test the powers of the new instrument and to employ them to the highest advantage.
The stars of the Pleiades have, from the earliest times, attracted the special notice of observers, whether savage or civilized. Hence, on the one hand, their prominence in stellar mythology all over the world; on the other, their unique interest for purposes of scientific study and comparison. They constitute an undoubted cluster; that is to say, they are really, and not simply in appearance, grouped together in space, so as to fall under the sway of prevailing mutual influences. And since there is, perhaps, no other stellar cluster so near the sun, the chance of perceptible displacements among them in a moderate lapse of time is greater than in any other similar case. Authentic data regarding them, besides, have now been so long garnered that their fruit may confidently be expected at least to begin to ripen.
Dr. Elkin determined, accordingly, to repeat the survey of the Pleiades executed by Bessel at Konigsberg during about twelve years previous to 1841. Wolf and Pritchard had, it is true, been beforehand with him; but the wide scattering of the grouped stars puts the filar micrometer at a disadvantage in measuring them, producing minute errors which the arduous conditions of the problem render of serious account. The heliometer, there can be no doubt, is the special instrument for the purpose, and it was, moreover, that employed by Bessel; so that the Konigsberg and Yale results are comparable in a stricter sense than any others so far obtained.
One of Bessel's fifty-three stars was omitted by Dr. Elkin as too faint for accurate determination. He added, however, seventeen stars from the Bonn Durchmusterung, so that his list comprised sixty-nine, down to 9.2 magnitude. Two independent triangulations were executed by him in 1884-85. For the first, four stars situated near the outskirts of the group, and marking the angles of quadrilateral by which it was inclosed, were chosen as reference points. The second rested upon measures of distance and position angle outward from Alcyone (η Tauri). Thus, two wholly unconnected sets of positions were secured, the close accordance of which testified strongly to the high quality of the entire work. They were combined, with nearly equal weights, in the final results. A fresh reduction of the Konigsberg observations, necessitated by recent improvements in the value of some of the corrections employed, was the preliminary to their comparison with those made, after an interval of forty-five years, at Yale College. The conclusions thus laboriously arrived at are not devoid of significance, and appear perfectly secure, so far as they go.
It has been known for some time that the stars of the Pleiades possess a small identical proper motion. Its direction, as ascertained by Newcomb in 1878, is about south-southeast; its amount is somewhat less than six seconds of arc in a century. The double star 61 Cygni, in fact, is displaced very nearly as much in one year as Alcyone with its train in one hundred. Nor is there much probability that this slow secular shifting is other than apparent; since it pretty accurately reverses the course of the sun's translation through space, it may be presumed that the backward current of movement in which the Pleiades seem to float is purely an effect of our own onward traveling.
Now the curious fact emerges from Dr. Elkin's inquiries that six of Bessel's stars are exempt from the general drift of the group. They are being progressively left behind. The inference is obvious that they do not in reality belong to, but are merely accidentally projected upon, it; or, rather, that it is projected upon them; for their apparent immobility (which, in two of the six, may be called absolute) shows them with tolerable certainty to be indefinitely more remote—so remote that the path, moderately estimated at 21,000,000,000 miles in length, traversed by the solar system during the forty-five years elapsed since the Konigsberg measures dwindles into visual insensibility when beheld from them. The brightest of these six far-off stars is just above the eighth (7.9) magnitude; the others range from 8.5 down to below the ninth.