Fig. C shows a drip feed or “dribbling” burner in which the oil pours out of the upper port and over the lower port through which the steam or air issues. As would be expected, the atomization is not as perfect with this burner as with the atomizer or injector type. [Illustration: Fig. I. Sheedy Oil Burner, Used for Locomotives. ] A burner in which the oil and steam mix before passing out into the furnace through the final opening is known as a “Chamber burner,” and is shown by Fig. D. In some respects, at least in construction, it is similar to the injector burner, but it does not possess the lifting abilities of the latter because of the open space in front of the steam nozzle. The atomization takes place largely within the burner because of the eddy currents of air and oil vapor created both by the vapor striking the walls of the outer tube and by the large space in which it has to circulate before passing out of the orifice. An external blast burner as shown by Fig. E, in which the oil is forced out of the openings (3–3) at the extreme end of the burner atomizes by blowing the oil off of the tube by jets of steam directed by a series of annular openings in a disc. This is really a type of atomizer burner as will be seen by close inspection. This type must be very carefully constructed and the steam jets must be kept very clean in order to have good results for a little variation in the pressure or a small particle of dirt in the openings will deflect the steam and prevent a perfect oil spray. It’s one advantage lies in the fact that the oil and air are always separate and therefore minimize the danger of carbonization. [Illustration] It should be noted that the figures just shown in the illustration of the various classes of burners are diagrammatic only, and that many modifications in detail are made in the practical burner such as regulating valves, sliding steam nozzles, etc. A burner much used in stationary engine practice and with heating furnaces, where air at two or three ounces pressure is available, is the mixed pressure burner shown by Fig. F. In this burned steam or air compressed, to say 80 pounds per square inch is used for breaking up the fuel oil. A blast of air at low pressure but with considerable volume is used to support combustion in the furnace. The steam or compressed air enters the burner at (5) and meets the oil at the nozzle (8) where it is sprayed into the chamber (9). The oil enters the burner by the pipe (4), flows into the annular passage around the steam nozzle and meets the steam at (8). It will be noted that the steam nozzle (5) is free to slide back and forth in its casing so that the relation between the steam nozzle and spray nozzle may be adjusted to meet different operating conditions. This adjustment is affected by the levers (10) at the end of the burner.