substances in situations where there can be no abstraction of heat. [Footnote 1: Paper clx., in the Transactions of the Society, 1878, vol. vii., pages 109-168.] When a piece of ice of considerable size comes in contact under water with ice or other substance, it would usually touch in an area very small in proportion to its mass, and other forces acting upon it, and tending to move it, would usually exceed the freezing force, and regelation would not take place. In the minute needles formed at the surface of the water the tendency to adhere would be much the same as in larger masses touching at points only, while the external forces acting upon them would be extremely small in proportion, and regelation would often occur, and of the immense number of the needles of ice formed at the surface enough would adhere to produce the effect which we observe and call anchor ice. The adherence of the ice to the bed of the stream or other objects is always downstream from the place where they are formed; in large streams it is frequently many miles below; a large part of them do not become fixed, but as they come in contact with each other, regelate and form spongy masses, often of considerable size, which drift along with the current, and are often troublesome impediments to the use of water power. Water powers supplied directly from ponds or rivers, or canals frozen over for along distance immediately above the places from which the water is drawn, are not usually troubled with anchor ice, which, as I have stated, requires open water, upstream, for its formation. * * * * * A PAIR OF COTTAGES. This drawing has been admitted into the Exhibition of the Royal Academy this year. The cottages are of red brick, tiled roof, white woodwork, as usual, rough-cast in the gables; but they are not built yet. Design of Arthur Cawston.--_Building News_. [Illustration: SUGGESTIONS IN ARCHITECTURE.--A PAIR OF ENGLISH COTTAGES.--BY A. CAWSTON.] * * * * * DELICATE SCIENTIFIC INSTRUMENTS. By EDGAR L. LARKIN, New Windsor Observatory, New Windsor, Illinois.