The author prefaced his observations with some remarks on force in the abstract, referring in particular to the force by which crystalline architecture is accomplished. Some phenomena of crystallization were shown by means of the photo-electric microscope. The manner in which the molecular aggregation was affected when a beam of radiant heat was sent into the interior of a mass of ice, was examined. The track of such a beam presented a beautiful appearance--flattened spheroids were observed,

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... ch at certain incidences of the light shone with more than metallic brilliancy, and around each a liquid flower, consisting invariably of six petals, was formed. The spo.t at the centre of each flower was proved to be a vacuum, and the formation of the flowers in a piece of ice through which a beam of electric light was transmitted was rendered visible to the audience. The air and water cavities, which, in the case of glacier ice, have caused so much discussion, were next examined. It was proved that the water was due to the melting of the ice round the air cavities. The hypothesis propounded by M. Agassiz and the Messrs. Schlagintweit to account for this water, and which has hitherto been universally accepted, is, that the ice permits the radiant heat to pass, the heat warms the air, and it in its turn melts the ice. It was proved by the speaker that this view is wholly untenable. One of its consequences would be that a bubble ~)f air would be capable of absorbing in a few minutes a quantity of heat which would raise its temperature upwards of 400,000 degrees, or more than 160 times that of fused cast iron. The melting of the ice was shown to be a simple consequence of the dynamical theory of heat : molecular motionis transmitted through the solid ice, without prejudice to its solidity, and detaches the particles:at the surface of the internal cavity, as the last of a series of elastic balls is detached byforce Which has traversed a row of them without producing visible separation. The passage of snow into glacier ice was next considered. It was referred to the enormous pressure of the moist neve upon its own mass. That moisture was necessary, was shown by moulding ice at 32 deg. into cups ; while, when it was rendered perfectly dry by immersion in a bath of solid carbonic acid and ether, the ice on being crushed became ~ powder as white as snow. Crushed glass or quartz could not have been whiter or more opaque. tTodges' _Patent Triangular Scales and Gauges.t Mr. R. E. Hodges, of Southampton-row, Russell-square, the ingenious inventor of the india rubber accumulator springs, and other useful contrivances, has introduced a new description of scales and gauges, which are attracting notice at the Society of Arts' Exhibition of Inventions. The accompanying engravings illustrate the nature of these instruments. Fig. 1 is a strip of wood, ivory, or metal, supposed to be 10 inches long andl inch wide, with a diagonal cut severing it in two. Each inch is divided into 10, and the whole into 100 parts (divisions of