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]

[Footnote 1:  “Determination of the Relative Positions of the Principal Stars in the Group of the Pleiades.”  By William L. Elkin.  Transactions of the Astronomical Observatory of Yale University, Vol.  I., Part I. (New Haven:  1887.)]

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 deg., 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.