It may

tor, the tumbling barrels, and the machines in the chipping room. be preferred to have two motors, one to be used only for running the blower, and run for a few hours only when a heat is on, and the other constantly, for driving the machinery above mentioned. These motors may be located side by side in the blower room, as shown. The blower may be placed on the floor, but it is often advisable to locate it overhead, out of the way of dirt and dust and more nearly on a level with the tuyeres of the cupolas, so that some of the curves in the blast pipes may be avoided, as this is a very important matter when the amount of air pressure is to be compared to the power necessary to generate it, as in this class of blowers it is considerably more than is generally supposed, even by good mechanics.

The motor, or one of them, may furnish power to operate the traveling crane by the old system of a square shaft running the length of the building beside it and so providing power at any point in its travel; but this method is a rather clumsy way to transmit power, and it is a much better system to have the traveling crane carry its own motor, the current being supplied to it by flexible, pendant cables near the wall and out of the way. These should be placed on the side of the building opposite the cupolas, where there will be no obstruction to them and where they will be away from the excessive heat.

The general molding floor of the foundry should have its work so arranged that the spaces outside of the supporting columns will be devoted to the lighter floor work and the bench work, where crane service is not needed. A bench

is provided along one side as far as the heating apparatus (which occupies the outer front corner), for bench, or snap flask work. Here it will be found very convenient to use the compressed air hoists for floor work, as it will be in other parts of the plant, as the hoists may be suspended overhead and used not only for drawing the deeper patterns but for turning over flasks, for it is now a demonstrated fact that in compressed air we have a very useful, convenient, and efficient power, which may be utilized in the foundry, perhaps to as good or better advantage than in any other department of the modern manufacturing plant. Its uses are many, and the conveniences with which be carried to any part of the floor for individual use, or for the lifting of quite heavy loads, renders it almost indispensable in the routine work of the foundry. The economy of its use may be readily appreciated when it is remembered that an air compressor provided with a cylinder 6 inches in diameter, and a storage tank 3 feet in diameter and 5 feet long, compressing air to 80 pounds per square inch, will furnish ample supply for a dozen hoists lifting 400 pounds or more each.

it

may

In drawing patterns, turning small flasks, setting large cores, and similar work, these hoists may be suspended in any desired location, the rubber hose attached bringing a supply of compressed air, easily controlled by a simple valve. These hoists may be suspended from a trolley traveling on an overhead beam, so located as to be convenient to the work. Of course, larger hoists may be used when necessary, and they are quite as effective and economical. Roughly speaking, a hoist with a 3-inch piston should lift 450 pounds; with a 4-inch piston, 800 pounds; with a 6-inch piston, 1,850 pounds; and with an 8-inch piston, 3,300 pounds. A supply of compressed air is very useful in the chipping room, where chipping tools may be very efficiently operated with it, and by its use one man may thereby do the work of at least two, and usually more.

An air compressor may be located in the blower room, as indicated in Fig. 115, and operated by the motor situated there. A cylinder 12 inches in diameter will be ample for the ordinary uses of the foundry floor and for operating such tools as are necessary in the chipping room.. It will require a tank about 4 feet in diameter and 8 to 10 feet in length. This may be situated over the air compressor so as not to occupy the floor space. Such a tank should, of course, be constructed on the same lines and of like materials as a steam boiler of similar size, and to withstand the same pressure per square inch. It should be remembered that under ordinary circumstances, if the air compressor is constructed on the plan of the boiler-feed pump, with a steam cylinder and an air cylinder, with one piston common to both, the proportions will be nearly these, viz.: steam cylinder, 6 x 8 inches, and air cylinder 10 x 8 inches. And also, that 90 pounds steam pressure will give

about 65 pounds air pressure, with a piston velocity of 300 feet per minute. These figures are given as nearly correct and easily remembered.

A large variety of molding machines are in the market, many of which are admirably designed to turn out a large quantity of work in a day, and to save much of the manual labor usually necessary. They are, of course, employed on comparatively plain work where the tamping of the sand may be easily done by forcing down upon it a comparatively flat surface. They are usually employed upon the lighter kinds of work.

Molding machines are also made for molding the teeth of gear wheels of large dimensions, as well as large segments, and by their use much time is saved and the cost of large and expensive patterns for the gear teeth is avoided. There are also molding machines for pulleys, which are valuable as a part of the foundry equipment, and with a proper supply of rims and spiders this work is much simplified and the costs reduced.

These machines must be selected and provided in accordance with the particular class of work to be done, as their utility will depend almost entirely upon this matter.

Sand sifters and sand mixers are now made so as to be mounted upon a tram car and are driven by a small electric motor attached to them, the machine being thus rendered complete in itself, and may be easily moved to any part of the foundry desired and, when not in use, run out of the way. They will be found very convenient on nearly all classes of work, and may supersede the usual hand riddles almost entirely, saving much of the molder's time and producing better castings, as more sifted sand is likely to be used if the molder is not obliged to sift it by hand. Besides, being sifted close at hand, it is not so liable to contain foreign matter as if it is sifted at one point and carried to different parts of the foundry where it may be needed.

The deep molding pits are located as shown by dotted lines in Fig. 115, one 8 x 12 feet, and the other 12 x 18 feet. These may be of any required depth, but more usually the smaller one would be about 5 feet and the larger one about 8 feet. All these dimensions should, of course, be made according to the character, size, and the weight of the larger castings to be made. The walls and floors of the pits should be constructed according to the directions given in the chapter on Shop Floor Construction, in Part First of the work. These pits will be found very useful in molding large pieces wherein a very deep nowel flask would be required, and which would necessarily raise them several feet higher on the floor than would be the case where a pit is made use of. Such pieces, which may not be cast on their side, and weighing, say, over 4 tons, will usually be found fit subjects for pit molding.

It will be noticed that the cupolas have been located within the space of the foundry proper. This, of course, will occupy considerable room on the

foundry floor. They are so placed in many foundries, this being a more desirable location in several respects. In this case they come nearer to the cranes, which are supported from the main columns, and afford a convenient means of transferring a ladle of melted iron from the cupola front to the cars, and thence by the track to any point in the foundry, or from the cranes over to the traveling crane and thence to any part of the central space of the floor. The cupolas may be located in the cleaning room and the blower room space, and thereby save about 140 square feet of molding floor space. In this case the cranes will be placed closer to the wall, but yet with sufficient reach to pass ladles of melted iron to the car track, or to the traveling crane.

If this disposition is made the location of the tumbling barrels will need to be changed, placing one at the front of the room. If it is found necessary, the motors and the air compressor may be placed on the charging floor, where there is ample room for them. Even the blower may be located there, for the purpose of affording more space on the first floor, a partition dividing them from the charging floor proper. The stairs also may be placed at right angles to their position as shown, for the purpose of affording any specially desired location for the first-floor equipment. In case the cupolas are placed in the cleaning room and blower room space, it may be advisable to run a car track immediately in front of them, connecting at each end with the transverse tracks by the usual turntables, and by which means ladles of melted iron may be transferred to the central space under the traveling crane by taking the route either to the right or left, as may be the shorter distance. However, many will prefer the jib crane for this service, as being quick, efficient, and safe.

In the back corner of the main part of the foundry proper is the foreman's office, and adjoining it is a storeroom for the various small articles, tools, etc., necessary for almost daily issue, and which the foreman of a foundry of this size will probably find necessary to have under his personal control, although it will be advisable to have an employee in the office who is conversant with these matters, and to act as a bookkeeper, in order that the foreman's time may not be too much taken up with these matters of routine details.

In the front corner, on the outer side, is located the heating apparatus, which has been previously described in the general chapter on Heating, in Part First on Shop Construction. If preferred, it might as well be located in the corner next to the flask room. This would be convenient if more bench room was required for snap flask work.

The chipping room is provided with the usual benches, having a sufficient number of vises on them to accommodate the work requiring hand chipping. Sprues are cut off in the sprue cutter where this can be done by such a machine. The three emery wheels will do much of the small finishing on the castings,

should be so constructed that the pickling solution may drain off into a receptacle where it may be saved and used again, while the water used in washing

while the pneumatic chipping tools will do very much of the work on the heavy castings.

Pickling beds are provided for, as shown on the plan, Fig. 119. These