The London Journal of Arts and Sciences " contains an article on testing the brick-beam erected at the Great Exhibition last year with Portland cement. In England no artificial hydraulic cement was discovered until the experiments of Mr. Frost, who was the real discoverer of the Portland cement. This hydraulic cement has superior qualities to any other; it is capable of setting very fast in water, and it can also be used as a mortar. The Portland cement is made of clay mixed in certain proportions with chalk, then ground in water and afterwards burned. It is submitted to a high heat, and has been called over-burned lime. It is now used extensively in England for docks in harbors, for stucco work, the construction of cisterns, &c. The discoverer of this cement conferred a great boon upon England ; he came to this country a number of years ago, and resided for a long time in the city of Brooklyn, in which place he breathed his last at a good old age, the early part of this summer. His experiments with steam, and his pamphlet on stame (steam heated apart from water) which he termed "a substance with new qualities," are well known to the public. He was a man of a very gentlemanly appearance, he possessed great ingenuity and engineering skill, was an excellent practical electrotypist as mentioned by Dr. Lardner in his lectures in 1841, and had a very extensive knowledge of chemistry. There were few, if any, men in our country possessed of more general information connect- id with engineering than Mr. Frost. At one ;ime he was possessed of considerable wealth, >ut his latter Hays were spent, though not in svant, in comparative poverty. He was an nventor, and the last days of his life were like ihose Of too many of that benefit-conferring :lass; he benefited others, to the injury of limselt