Competitors sending names should be particular to mark "Prize List" on their orders, and remit the amount of subscription, as per terms. All Clubs of 10 names and upward, will be taken at the rate of $2.50 per annum. To those who do not compete for the Cash Prizes the publishers offer the Splendid Steel Engraving, in size 22x36, entitled "MEN OF PROGRESS-AMERICAN INVENTORS." It contains the following group of illustrious inventors, namely: Prof. Morse, Prof. Henry Thomas Blanchard, Dr. Nott, Isaiah Jennings, Charles Goodyear, Jos. Saxton, Dr. W. T. Morton, Erastus Bigelow, Henry Burden, Capt. John Ericsson, Elias Howe, Jr., Col. Samuel Colt, Col. R. M. Hoe, Peter Cooper, Jordan L. Mott, C. H. McCormick, James Bogardus, and Frederick E. Sickles. The likenesses are all excellent, and Mr. Sartain, who stands at the head of our American Engravers on Steel, in a letter addressed to us, says "that it would cost $4,000 to engrave the plate now," which is a sufficient guarantee of the very high character of the Engraving as a work of art. Price of the Engraving, $10 for single copy. To enable all to possess this beautiful work of art, at, a very reduced rate, the SCIENTIFIC AMERICAN will be sent one year, together with a copy of the picture, on receipt of $10 Any one sending 10 Names for 1 year, and $30, will receive one picture 20 " " 50, " " " 30 " " 75, " two pictures 40 " " 100, " three " 50 " " 125, " four " Competitors for the above prizes can send in names at any time on or before February 10th, and from any postoffice. For full particulars and sample copies of the SCIENTIFIC AMERICAN, address the Publishers. Terms of the SCIENTIFIC AMERICAN: Single copy one year, $3.00; six months, $1.50; and one dollar four months. To Clubs of ten and upward, $2.50 each per annum. MUNN & CO., 37 Park Row, New York