mentioned shall be in compliance with Specifications for Ohio State University coal.

Natural gas will be used only in the auxiliary engines for starting the plant, shall contain not less than 1,000 B.T.U. per cu. ft. at 60° F. and 30-inch mercury and cost not to exceed 20 cents per thousand cubic feet.

The water used in this plant will be purchased under contract from the Columbus City Water Works at a price not to exceed 12 cents per 1,000 gal. The water not to contain over 80 grains of solids per gallon.

All foundations will be made of concrete, the composition of which shall be:

First grade Portland cement, 1 part. Good sharp sand (containing not more. than 2 percent loam), 3 parts.

Washed gravel or broken stone of a size that will pass through a 2-inch ring and over a 1-inch ring, 5 parts.

The concrete to be laid in layers not to exceed six inches in depth and each layer thoroughly tamped before the next is put in. The price, including excavation, not to exceed $8.00 per cubic yard.

Specifications for Equipment of
Ohio State Power Plant.

These specifications are intended to require and include all work and material necessary or proper for the work contemplated, in case, by inadvertance or otherwise the plans or specifications omit to require some work or to provide the same so that the work may be complete according to the true intent and purpose of the plans and specifications.

All material used in the construction and all workmanship shall be accepted by the official in charge. Materials and workmanship not accepted shall be replaced by the contractor without expense to the Ohio State Power Company.

Unless otherwise herein provided for, all materials and apparatus shall be installed and connected, ready for regular operation, in a thorough and workmanlike manner by the contractor, who shall furnish all foundations and supports. The Ohio State Power Company will furnish all necessary storage, right of way, permits and authority for the installation and operation of all apparatus herein specified and designate the location of the apparatus before the work is begun. The contractor or contractors shall operate

continuously under normal rated load until accepted by the official in charge, provided that time shall not exceed sixty (60) days after the starting thereof.

The contractor shall furnish the Ohio State Power Company, promptly after signing contract, with plans and layouts for foundations and for all apparatus included in the contract. These shall show dimensions and details and be subject to the approval of the official in charge.

The contractor shall guarantee all apparatus included in this contract to be of full capacity as rated, and he shall correct any defects which shall develop in said apparatus within one year from the starting thereof, provided the Ohio State Power Company gives the contractor immediate written notice of such defects and provided further that during said period said apparatus shall not be taxed beyond its normal capacity, shall be regularly cleaned and cared for, and shall be operated normally and properly.

Specifications for Coal and Ash
Handling Equipment.

The coal storage shall consist of structural steel, brick or concrete lined, coal bunkers, supported on suitable steel columns above the producers and provided with telescoping steel spouts for conveying the coal to the producer charging hopper by gravity. The total available capacity of these bunkers shall be 90,000 cu. ft. (corresponding to 2,000 tons of coal).

or

kers from an ample track hopper by The coal shall be conveyed to the bunJeffrey pivoted, elevator - conveyor, equal. The conveyor to run parallel to the length of the producer house and over the coal bunkers. The same conveyor shall pass under the producer ash pits. and be so arranged as to carry the ashes from the producers to a suitable elevated gravity into cars for disposal. ash bunker. The ashes to be loaded by

All steel construction shall be in com

pliance with Fouler's latest specifications.

Specifications for Suction
Producer Plant.

The producer plant shall be of the suction type, dry bottom, and shall comprise in general, the following parts:

5 Gas Generators (six sections each), with fire brick lining.

2 Saturators with thermostat control. Air

1 Tar Trap.

5 Standard Valves. Gauge Boards.

Piping and Valves connecting all parts of the equipment.

The generators shall be built of structural steel securely braced both vertically and longitudinally and provided with fire. brick lining at least twelve (12) inches thick. The top of each producer section shall be removable and shall be protected from heat of producer by eight (8) inch terra cotta tile firmly cemented in place and supported by structural steel shapes.

A water cooled gas off-take built of steel and welded at the seams, shall be provided in the upper part of each generator, and shall be supported from the head.

Coal shall be fired to the generator by means of twelve (12) charging hoppers on each generator, arranged so that fuel can be charged without admitting air to the producer.

Two cleaning doors shall be provided on each side of each section of the gas generators to give ready access to grates and ash pit.

The generators shall be provided with inclined stoking grates, mechanically operated. The arrangement of the drive shall be such that either side of any section can be stopped or started independent of any other side or section, and the speed of the whole grate mechanism shall be variable at the will of the operator.

The bottom of the fuel column shall be supported on a flat shaking grate operated by compressed air cylinders. One air cylinder for each section shall be provided. These shall be operative at the will of the attendant.

The plant shall be equipped with two steel towers filled with wood grids for the purpose of saturating the blast before entering the ash pit. These saturators shall be equipped with a thermostat for the purpose of controlling the temperature inside the towers so as to maintain a suitable quantity of water vapor in the blast to the producer.

Gas engine exhaust heaters shall be used for heating the water supply to the satur

ator and suitable heaters are to be included for this purpose.

A suitable pump shall be provided for the purpose of circulating the water through the saturators.

The blast on leaving the saturators shall be conducted through a suitable manifold equipped with thirty (30) branches which shall terminate at the center of each section of the ash pit. A blast gate shall be provided in each branch so that the air entering each section can be controlled and varied to suit requirements.

Suitable gauges shall be provided to indicate the pressures in the blast pipe to each section.

A primary cooler shall be mounted beside the producer on the charging floor and connected to the gas off-take of each producer. This cooler shall be of the static type equipped with water sprays.

From the top of the primary cooler the gas shall be conveyed through a steel riveted pipe to a suitable gas header. This gas header shall be common to the five producers. A shut-off valve shall be provided in the gas main from each producer.

The tar extractor shall be of the frictional static type, and shall consist of eight (8) reversible diaphragm holders. These shall be of such size that five diaphragms only shall be required to scrub the gas from this plant, the additional diaphragms being provided for spares. This tar extractor shall be capable of reducing the total non-gaseous impurities in the gas to 0.005 grains per cubic foot.

Five Connorsville, Boston type gas pumps or equal, shall be provided to draw the gas from the producers and deliver it to the tar extractor and gas main. Each gas pump shall be furnished with a direct connected induction motor, mounted upon a common sub-base and connected to the gas pump by means of a solid coupling. Each gas pump shall have a capacity of two hundred thousand (200,000) cubic feet of gas per hour, and shall be capable of maintaining a pressure at the secondary cooler outlet of not less than two (2) inches, measured by water column and not more than two (2) pounds gauge per square inch.

After leaving the tar extractor the gas shall pass through a secondary cooler of the static type, which shall be equipped with water sprays for the purpose of reducing the gas to atmospheric temperature. Furnish a suitable pump for this purpose.

A steel tar trap shall be provided at the outlet from the tar extractor. This trap shall be provided with a drain so that all tar can be collected at one point.

A stand over valve shall be provided and mounted above the primary cooler. Means shall be provided for opening and closing this valve from the operating floor. Suitable gauges shall be provided to indicate the pressures in the various parts of the apparatus.

All the piping and fittings for connecting the various parts of the producer apparatus shall be provided.

One recording gas calorimeter arranged with a 60-cycle, three-phase motor for

per cu. ft., a minimum hydrogen content of 12 percent, and containing not more than 0.005 grain per cu. ft. non-gaseous impurities, delivered to the engines at a pressure corresponding to 2-inch water column. The engines to have an approximate cylinder diameter of 34 inches, stroke of 48 inches, run at 100 r.p.m., and have a capacity of 1,500 k. w. (at 80 percent P. F. 1,875 k.v.a.) and an overload capacity of 25 percent.

The main bed plate of these engines shall be of the Tangye Rolling Mill type, of close grained cast iron, and to be filled and painted. The main journal housing to be cast solid with the bed plate and be

driving sampling pump shall be supplied for each unit.

A motor-driven tar pump shall be provided of sufficient size to handle all of the tar from both tar extractors and primary coolers. Means shall be provided for returning the tar to the producer to be gasified.

All parts of the producer apparatus shall be given one (1) coat of paint before shipment. Bitumastic paint shall be used for this purpose.

The regulation of the gas pressure shall be accomplished by automatic by-pass regulators.

Specifications for Gas
Engine Units.

Furnish seven 1,500 k. w. horizontal, twin tandem, double-acting, 4-cycle, pressure producer gas engines. These to develop their rated power while using producer gas of not less than 100 B.T.U.

fitted with removable shells having side adjustment by means of wedges. The lower shells to rest in a bored seat. The bearing shells to be lined with the best quality of babbitted metal, hammered to the proper density, scraped to a bearing surface and properly grooved for the distribution of oil.

The cylinder must be of tough cast iron with a liner of hard close grained iron, have adequate water jacket and ample means for cleaning same.

The cylinder heads shall be made in one piece, of the same material as the cylinder proper, and arranged for water cooling. They shall carry the piston rod packing gland. The joint between the cylinder and cylinder head shall be at the inner end of the head on a packed conical seat. The front of the cylinder shall be fastened to the engine frame by studs and nuts of ample size and number. The tie piece shall be a rigid cylindrical

Years ago, when the establishment of the grain raiser of the West grew from a modest farm of a few hundred acres to the immense ranch where it took an entire day to run a single furrow around a field, it became evident that the old-fashioned hand methods of plowing, reaping and threshing were entirely inadequate, not only because of the cost, but more especially because it was impossible to find enough men to do the work. This condition was met by the reaping machine, which later became a header, and was also combined with a thresher, thus evolving a harvesting outfit of great capacity.

These combinations were heavy to haul and also required considerable power for the various mechanical operations, and with increased demands for service the simple reaper requiring two horses grew to a huge machine drawn by thirty powerful animals; and here the limit in size and efficiency practicable with this kind appeared to have been reached. The steam threshers seemed not to have power, and even when the desirable substitute for horse power, and even when the internalcombustion motor became practical its use was confined to the operation of the mechanism but not the machine. All of this has now been overcome by the improvements that have been made in heavy traction devices, and the latest harvesting apparatus is a complicated machine that does everything but grind the grain which it gathers.

Harvesting that is almost automatic is now possible by means of a self-propelled combined harvester which has reached the commercial stage. Since the early eighties, when a header and a thresher were combined to make the horse-drawn harvester, three other machines have been incorporated, viz., a recleaner, a gasoline engine, and a "caterpillar" track, which propels the outfit forward.

The heads and a short section of the straw are cut by the header knife falling upon the draper, an endless canvas belt which elevates them to the feeder. Back of the feeder, a rapidly revolving threshing cylinder knocks the grain out of the heads. Revolving beaters, pickers, and endless straw carriers continue the separation, finally throwing the straw out at the rear of the machine, either in large bundles or a continuous windrow. The grain is

elevated to the cleaner, thence delivered into sacks, which are still sewed by hand, and dumped six in a place on the ground. Unthreshed heads go back to the feeder for a second trip through the cylinder.

The separator is kept level on steep hillsides by a swinging frame which permits one wheel to be dropped and the other raised, the header meanwhile conforming to the slope of the hill, sometimes over 45 percent. The gasoline motor was first added to horse harvesters to maintain a steadier motion for threshing, regardless of the forward progress of the outfit, and to reduce the animal power required. In the self-propelled harvester it, of course, furnishes power, not only for the cutting and threshing as before, but also for propulsion.

Four men operate the self-propelled outfit, one driving, another tending the header, a third the separator, and a fourth sewing sacks. They put as much wheat into the sack in ten hours as six hundred men working with scythes and flails, with a considerable advantage in cleanliness of output.

The use of the motor and endless steel track for propelling eliminates from sixteen to twenty-six horses.

Combines have been common on the Pacific coast for thirty years, but the self-propelled machine is a commercial novelty within the last two-Scientific American.

New Machinery Dealers.

E. P. Rhodes, former mine operator of this district, and C. G. Boyer, one of the pioneer machinery dealers of Joplin, have formed a partnership under the firm name of the Boyer-Rhodes, Machinery Company, with headquarters at 311 Virginia avenue, where they have spacious quarters for storing their various lines of mining machinery.

The company will specialize on St. Marys gas and oil engines, many of which already are in use throughout the district. Operators who are using these engines are very high in their praise of their efficiency. W. H. Gillete of the St. Marys Company, has been in Joplin for the past week or two, helping the new firm get its equipment installed.-Joplin, Mo., Herald.