HYDRAULIC CEMENT Of the very highest order and quality made any and everywhere from Refuse or Decomposed Limestone, Marble, Shells, Chalk and Clay, and River Deposit as per Letters Patent. Address JOHN DIMELOW, Laboratorian, Austin, Texas. PARIS EXHIBITION PRIZES. FULL Official List of the Awards in the American Department, enumerating Exhibits and Names and Addresses of Exhibitors, with kind of Prize awarded in each case. SUPPLEMENTS 149, 150. Price 10 cents each. [Illustration: WROUGHT IRON BEAMS & GIRDERS] THE UNION IRON MILLS, Pittsburgh, Pa., Manufacturers of improved wrought iron Beams and Girders (patented). The great fall which has taken place in the prices of Iron, and especially in Beams used in the construction of FIRE PROOF BUILDINGS, induces us to call the special attention of Engineers, Architects, and Builders to the undoubted advantages of now erecting Fire Proof structures; and by reference to pages 52 & 54 of our Book of Sections--which will be sent on application to those contemplating the erection of fire proof buildings--THE COST CAN BE ACCURATELY CALCULATED, the cost of Insurance avoided, and the serious losses and interruption to business caused by fire; these and like considerations fully justify any additional first cost. It is believed, that, were owners fully aware of the small difference which now exists between the use of Wood and Iron, in many cases the latter would be adopted. We shall be pleased to furnish estimates for all the Beams complete, for any specific structure, so that the difference in cost may at once be ascertained. Address CARNEGIE, BROS. & CO., Pittsburgh, Pa. $7 A DAY to Agents canvassing for the FIRESIDE VISITOR. Terms and Outfit Free. Address P. O. VICKERY, Augusta, Maine. B. W. Payne & Sons, Corning, N. Y. Established in 1840. [Illustration] EUREKA SAFETY POWER. +----+--------+--------+-----+------+-------+ |h.p.| cyl. | ht. |space| wt. |price. | +----+--------+--------+-----+------+-------+ | 2 |3-1/8x4 | 48 in. |40x25| 900 | $150 | +----+--------+--------+-----+------+-------+ | 4 | 4x6 | 56 |46x30| 1600 | 250 | +----+--------+--------+-----+------+-------+ | 6 | 5x7 | 72 |72x42| 2700 | 400 | +----+--------+--------+-----+------+-------+ Also, SPARK ARRESTING PORTABLES, and STATIONARY ENGINES _for Plantations_. Send for Circulars. _PERFECT_ NEWSPAPER FILE * * * The Koch Patent File, for preserving newspapers, magazines, and pamphlets, has been recently improved and price reduced. Subscribers to the SCIENTIFIC AMERICAN and SCIENTIFIC AMERICAN SUPPLEMENT can be supplied for the low price of $1.50 by mail, or $1.25 at the office of this paper. Heavy board sides; inscription "SCIENTIFIC AMERICAN," in gilt. Necessary for every one who wishes to preserve the paper. Address MUNN & CO., Publishers SCIENTIFIC AMERICAN. [Illustration: HOWE SCALE CO., Rutland, Vt. Paris 1878 Were awarded the GOLD MEDAL]