* * * * * THOMAS'S CONCENTRATED DYE Stuffs. (138 Recipes SENT GRATIS.) (See SCIENTIFIC AMERICAN SUPPLEMENT, March 15, '79.) Address N. SPENCER THOMAS, Elmira, N. Y. * * * * * [Illustration: Rotary Pressure Blower.] BAKER ROTARY PRESSURE BLOWER. (FORCED BLAST) Warranted superior to any other. WILBRAHAM BROS. 2318 Frankford Ave. PHILADELPHIA * * * * * "THE 1876 INJECTOR." Simple, Durable, and Reliable. Requires no special valves. Send for illustrated circular. WM. SELLERS & CO., Phila. * * * * * [Illustration: Cold Rolled Shafting.] The fact that this shafting has 75 per cent. greater strength, a finer finish, and is truer to gauge, than any other in use renders it undoubtedly the most economical. We are also the sole manufacturers of the CELEBRATED COLLINS' PAT. COUPLING, and furnish Pulleys, Hangers, etc., of the most approved styles. Price list mailed on application to JONES & LAUGHLINS, Try Street, 2d and 3d Avenues, Pittsburgh, Pa. 190 S. Canal Street, Chicago, Ill., and Milwaukee. Wis. [Right index] Stocks of this shafting in store and for sale by FULLER, DANA & FITZ, Boston, Mass. Geo. Place Machinery Agency, 121 Chambers St., N. Y. * * * * * VEGETABLE AND FLOWER SEEDS WE SELL EVERYTHING FOR THE GARDEN Descriptive Catalogues of 175 pages sent Free PETER HENDERSON & CO. _35 Cortlandt St., New York._ FLOWER AND FRUIT PLANTS * * * * * [Illustration: Engraving.] L. SMITH HOBART, President. JOHN C. MOSS, Superintendent. TYPE-METAL RELIEF PLATES. A SUPERIOR SUBSTITUTE FOR WOOD-CUTS AT MUCH LOWER PRICES. Persons desiring illustrations for Books, Newspapers, Catalogues, Advertisements, or for any other purposes, can have their work done by us promptly and in the best style. OUR RELIEF PLATES are engraved by photo-chemical means; are mounted on blocks type-high ready for use on any ordinary press, and will wear longer than the common stereotype plates. They have a perfectly smooth printing surface, and the lines are _as deep, as even,_ and _as sharp_ as they could possibly be cut by hand. ELECTROTYPES may be made from them in the same manner as from wood-cuts. COPY. The engraving is done either from prints or pen-drawings. Almost all kinds of prints can be re-engraved directly from the copy, provided they be in _clear, black lines_ or stipple, and on _white_ or only slightly tinted paper. Pen drawings, suitable for engraving by us, must be made with _thoroughly_ BLACK ink, on _smooth, white_ paper. They should usually be made twice the length and twice the width of the plates desired.