STATIONARY ENGINES.

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protected from injury at such places. As the flow of various kindsand conditions of grain through the spout from the hopper variesconsiderably, it is found desirable to place a pair of oblique siderollers at the point where the grain falls upon the band, in order togive it a slightly hollow form, and so prevent the grain fromspreading. In passing heavy quantities of grain along the bandsto great distances it has also been found expedient to apply atintervals pairs of these oblique side rollers, which are carried onmovable frames that can be set at any required spot.

The cross bands J J (Fig. 213), for conveying the current of grainin a direction at right angles to the main bands, are driven from thelower or return half of the main band, which is passed half rounda driving roller R, at each of the cross bands; and the motion iscommunicated from this roller to the cross bands through a pair ofmitre wheels S, having a clutch T for throwing the driving shaft inand out of gear. The cross bands or other machinery, such as thecentrifugal distributing fan, can also be driven by depressing thereturn half of the main band by a roller carried in a rocking frameso as to bring the band well into contact with a fixed roller situatedunderneath, which can then communicate the required motion forany purpose; and this simple mode of taking off power from themain bands has proved of Service in many ways.

A revolving fan for spreading the grain over the floors of thewarehouses, and for ventilating it and improving its condition, hasbeen used with success. This fan is carried upon an upright shaft,driven from the main band by the same arrangement as thatdescribed for driving the cross bands. As the band is required totravel in opposite directions, the fan is made with straight radialvanes, to allow of its revolving in either direction. The grain is ledby a spout on to the top of the fan, and to avoid the Separation ofheavy and light particles in the mass, and to spread it as evenlyover the floor as possible, the body of the fan has a conical form,the alternate blades being made of a different length and shape, asshown in the enlarged view, Fig. 214. A hinged tongue is placedin the end of the delivery spout above the fan, and the discharge ofthe grain can be directed to any particular spot by turning thistongue round in the required position. The fan is placed 9^4 feetabove the floor, and at its usual speed of 250 revolutions per minuteit deposits the grain in a circle of 45 feet diameter.

Five hydraulic cranes for discharging cargo are fixed in towers

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