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and then finished in subsequent firings. Sand-Lime, however, is an interesting departure from clay in the direction of low temperatures. It is due to Michaelis, who subjected an intimate mixture of lime and silica to the action of high-pressure steam for several hours. The resulting product consists of sand grains cemented together by a bonding substance. Apart from the calcium hydroxide or carbonate that may be present, this bonding material consists of a mixture of at least two and most likely three calcium silicates, which may be hydrated, the bulk being calcium meta-silicate, CaSi0 3 or CaSi0 3 ,H 2 0, and the others the ortho- and di-silicate. The Committee appointed (1911) by the Dutch Minister of Industry and Commerce to inquire into the relative merits of building ware made from clay and from sand- lime mixtures, concluded that for buildings intended to be permanent sand-lime brick is not sufficiently durable nor does it lend itself to architectural treatment, but with'n these limitations it is a useful ware. Its fracture should be smooth and straight, its absorption not more than 15 per cent. The first quality should withstand a crushing force of 200 kilos, per sq. cm. (approximately 2,8501b. per sq. in.) on an average of 10 samples, with a minimum of ISOkilos. per sq. cm. (2,5601b. per sq. in.). The second quality should average 150kilos. (2,1301b. per sq. in.) with a minimum of 135kilos. per sq. cm. (l,9201b. per sq. in.). The reproduction of a body is not merely one of analysis