Example of snap flask work on right-flasks removed-molds ready to be poured. Cylinder molds on left. Flasks with "cope" lifted off-pattern standing on top-core in position in lower half or "drag." Courtesy Cushman Motor Works, Lincoln, Neb. one-eighth of an inch to the lineal foot for cast iron; one-quarter inch for steel; three-sixteenths of an inch for brass and the same for aluminum. The amount allowed for machining will vary with the size and shape of the piece and the purpose for which it will be used. Great care must be exercised in making patterns to make them the right shape, to make them come apart readily at the places where the two or three parts join and, lastly, to give containing the dowel pins is laid to one side and the other half is laid flat side down on a board. One-half of a "flask," which consists of the four sides of a box having neither top nor bottom, is laid on the board over the pattern. Moulding sand is sifted upon the pattern until it is covered an inch or two deep. Then the coarser sand is shovelled on and rammed down hard. When the flask is full, the sand is struck off level with the top by means of a straight THE HERKEN JR. FRICTION CLUTCH PULLEY For your small and high speed engines. Can be fitted to any make of engine. Pulley has an oil chamber in hub with self-oiling arrangement and clutch has no springs or delicate parts to get out of order. All parts are interchangeable and there is no other clutch made to equal it for simplicity and efficiency. Insist on having a Herken Jr. on your engine, or write for Catalog C-4. THE MINSTER MACHINE CO., MINSTER, OHIO edge. A flat board covering the entire top of the flask is laid on top and the flask is inverted. This exposes the pattern embedded in the sand, with its flat surface level with the sand. The moulder now firms the edges of the sand around the pattern, and sprinkles the whole surface with what he calles "parting sand," which is a very dry, hard-baked sand which rattles off from the castings. The other half of the pattern is now set in place, and also the other half of the flask. Moulding flasks are always made in two parts and sometimes in three. They are provided with pins or guide pieces and staples to hold the two halves together and to enable the moulder to put the two parts exactly together again after they have been taken apart. With the top half of the flask in place, the molder sifts more fine sand on top of the mold, throws in a shovelful of coarser sand and begins to ram the sand down. His next operation is to set a "sprue," which is a wedge shaped piece of wood, on the top or to one side of the pattern. It is set in with the large end up. The sprue is held in place and sand rammed around it until the flask is filled, after which it is withdrawn. The top half of the flask is now carefully lifted off. The parting sand prevents the sand in the top half from adhering to that in the lower half of the flask, thus permitting the two halves to be separated. Each half flask now contains half of the pattern. These are carefully lifted out of the sand, the mold is slicked up, the upper half vented with numerous small holes made by a wire run through to the upper surface and lastly both depressions which contained the pattern are dusted with powdered graphite. The two halves of the flask are now set back together again. The pattern has been removed, thus leaving a hole down in the mold of the exact size and shape of the casting desired. All that remains to be done is to pour the metal through the sprue hole and, if the mold is properly made and vented so that the gases can escape, a good casting will result. It is allowed to cool slowly in the sand, and then the mold is broken up and the casting taken out and cleaned up. The sand used for molding must be of a particular variety known as molding sand and ordinary sand would not do at all. Molding sand is very fine and contains enough clay so when it is moistened it can be squeezed into a ball in one's hand. Molding and foundry work in general involve many intricate and highly specialized opera tions. The above very meager description is intended for those who have never seen a foundry, of whom there are many among our readers. While patterns are usually made of pine, some of the more intricate patterns are made from more costly woods like mahogany and other woods usually used only for cabinet work. The raised flowered designs used on some stove castings are made of wax which is glued or tacked to the wood base. Small patterns of not too intricate design from which a great many castings are desired are made of metal. Metal patterns do not warp or become distorted by moisture and they will last for years. The patterns for a new machine cost usually a great deal more than the machine itself. Manufacturers dislike to change the design of their machines because it usually means going to the expense of new patterns and of new tools and jigs in the shop, all of which are very costly. Patterns like those required for gas engine cylinders are very complicated because, instead of being cast solid, they are cast hollow-they are cored out, as the foundryman would say. Such patterns include also a set of core boxes in which the cores are molded. These are often more intricate and expensive than the pattern of the outside. The core is made from a mixture of molding sand, flour and molasses, which is rammed solidly into the core box. The box, which is made in halves, is opened up, the core removed and baked in a core oven. When a casting is made, the core is anchored in the proper place in the mold and the metal is poured around it. After the casting cools, the sand mold is broken in pieces and taken out through an opening that is left for that purpose. Usually one end of the core can be anchored in the side of the fold where an opening is cast in the side of the casting. For example, in figure 91, the prongs on the head of the cylinder casting are core prints. These project from the valve openings. The core is made to exactly fill these prints but not to fill the opening in the mold. The prints support the core at a number of points. The "Yellow Fellow" catalogs for 1914 are off the press and ready for distribution. There are three handsome catalogs, one on steam traction engines, another describing grain separators and a third devoted to gas and oil tractors and their line of famous self-lift plows. The acessories scribed in each catalog. These publications are and attachments belonging to each line are demonial letters. They are, rather, illustrated not mere picture books nor compilations of testitreatises on the various machines, interesting, accurate and expressed in excellent language. Any one who wishes to keep informed on farm tractors ought to have these books. They can be obtained by addressing the Avery Company, Peoria, Illinois. Miss Esther Raymond, of Cleveland, Ohio, is planning to walk from coast to coast, in company with another girl, wearing a khaki skirt a hunting jacket and no hat. A National Oil Engine WILL SOON PAY FOR ITSELF IN FUEL SAVED You buy an engine not for a day or a year but for a life-time. It behooves you, then, to "look before you leap." Don't let the first cost be the only thing considered. Look well into the construction-whether simple and of few parts or complicated and of many parts. Look to the equipment and the possibilities of equipment troubles; and then give due consideration to the very important question of fuel and fuel economy. AFTER A THOROUGH INVESTIGATION and years of costly experimenting, power users everywhere are turning to the National Oil Engine for the solution of their power problems. Why? They are cheaper to operate, cheaper to maintain, will stand harder service and are not affected by climatic conditions. They are free from all equipment troubles as they have no batteries, no hot tubes, no spark plugs or spark boxes, no valves to regrind, no magnetos or dynamos, no troublesome ignitor and THEY ARE OPERATED ON CRUDE OIL, STOVE OIL, GAS OIL, SOLAR OIL, DISTILLATE AND KEROSENE. Better let us send you a catalog with detailed description of construction and operation. Address Economy of the Gasoline Engine W. H. UNDERWOOD. THE gasoline engine is the most inexpensive and succesful means of power that can be used on the farm. This fact up-to-date farmers are fast awakening to. On a great many farms the gasoline engine has found a place of its own, and on some of the more progressive farms there are from four to eight engines, ranging in size from the 2-horse power, for use around the dairy, for pumping water, washing, sawing wood and other small jobs, to the massive 40horse power tractor, which in spring is used to do the plowing and cultivating, and at harvest power to run the forge, a work-shop, drill, etc., for the repair of tools and implements, a churn, separator, butter-worker, pump, and wood-saw and also a very important outfit on the farmnamely, the electric generating plant, for supplying light for the farm buildings and house, and power for washing machine or heat for toaster and flatiron. And thus the gasoline engine gives the farmer privileges and conveniences of the city, besides the use of electricity for heating and lighting purposes, which will help in eliminating the risk of fire. time to haul a string of binders and afterwards to do the threshing and run the ensilage cutter. The gasoline engine can be used equally as well on the small farm as on the large one. Practically every farmer, no matter what the product of the farm may be, can find profitable use for a gasoline engine. A small engine can be used to advantage on the small farm, while on the large farm use will be found for several. When a farmer begins to consider seriously the purchase of an engine he will often ask these questions, "What size shall I buy?" and "What will this size cost me?" These questions he may answer for himself by inquiring first of some manufacturer of farming implements as to the amount of power required to operate the machines he intends to use. Then when he has an idea of the amount of power he will need he can ask some reliable engine maker the cost of an engine of suitable power. For the average sized farm a 6-horse power engine will supply sufficient In using the engine about the dairy it is best to use a line-shaft large enough to accommodate belts from the separator, churn, butter-worker and pump. By using pulleys of the right sizes the correct speed for each may be obtained, which is a most essential point to bear in mind when setting up the engine, or engines, as a few revolutions per minute, more or less, will make a large difference in the satisfactory running of a fine-geared machine, such as a cream separa tor. At the barn the engine will perform most satisfactory work in operating the thresher, fanners, grinders, cutting-box, hay baler and bone-cutter. It is best to have such machines as will be convenient to operate at once connected on the lineshaft; that is, as many as the horse power of the engine will run without overloading it.The normal speed of an engine is the velocity or number of revolutions of the fly-wheel per minute that will best enable it to carry its full-rated load |