30 NOVEMBER 1912, Page 29

Two new volumes have been added to " Harper's Library

of Living Thought," namely, Rough Stone Monuments and their Builders, by T. Eric Peet, and Elements and Electrons, by Sir William Ramsay, K.C.B., F.B.S. (Harper and Brothers. 2s. 6d. net each.)—While both volumes are technical in nature, Mr. Feet's may readily be undertaken by the inexperienced. It must be con- fessed, on the other hand, that Sir William Ramsay's book, doubtless owing to the obscurity of its subject, requires some preliminary acquaintance with physics.