Popular Science Monthly 



277 



The shape of the stern of the motor-boat is also of vital importance since it affects speed as well 

 as seaworthiness and ability to run with the sea. Different shapes are adapted for different waters 



3^-in. bolts. Most of these reverse gears 

 have three notches, the center one being 

 neutral, so that the engine may be started 

 without turning the propeller in either 

 direction. The other two notches are for 

 full speed ahead or astern. Although some 

 of the gears are provided with two speeds 

 ahead, the majority of motor-boat operators 

 prefer to control the speed of the boat 

 by the speed of the engine and the latter 

 by means of the spark lever on the timer 

 or distributor in about the same manner 

 as the automobile is controlled. 



There are numerous steering devices on 

 the market, but those shown at H, I 

 and / are the most popular for motor-boat 

 use. Sketch 

 H shows the 

 common type 

 of steering 

 wheel where 

 the tiller-rope 

 passes around 

 the drum of 

 the wheel so 

 that turning 

 the wheel in 

 either direc- 

 tion neces- 

 sarily moves 

 the rudder. 

 In connecting up a wheel of this kind 

 the turns taken around the drum must be 

 uneven in number; that is, the tiller rope 

 should pass around the drum three or 

 five times and never two or four. Sketch / 

 shows a lever arrangement which is very 

 satisfactory as a side steerer, provided 

 the guard is set low enough to allow of 

 the lever being moved backward or forward 

 far enough to turn the rudder at an angle 

 of about forty-five degrees of the keel in 

 either direction. This type of steerer is 

 never used except on the side of the craft 

 so that one man may handle the engine 

 and the boat. Sketch / shows what is 

 known as the auto steerer, which is a very 



The position the engine takes relative to the boat hull for 

 directing the shaft downward at the stern end of the boat 



popular type for speed craft and the larger 

 cruisers. In this type, the wheel is between 

 the operator's knees, so that his hands 

 rest on it. The shaft of this apparatus 

 projects below the floor boards and has a 

 sprocket wheel on the extreme end, from 

 which passes the open-link chain which 

 the sprocket teeth engage when the wheel 

 is turned in either direction. The first- 

 mentioned type often causes some annoy- 

 ance through the tiller rope slipping on 

 the drum; this trouble may be overcome 

 by using either a small woven-wire cable 

 in place of cordage or a manila line having 

 a woven-wire cord. With the side steerer 

 there is very little trouble except that 

 caused by the 

 con tinual 

 shrinking and 

 stretching of 

 cotton or 

 hemp tiller 

 rope, but even 

 if the line 

 should get 

 slack it is a 

 very easy 

 matter to take 

 the slack out 

 at the eyes at 

 either side of 

 the lever or with a turn-buckle. The last- 

 mentioned type is preferably used in con- 

 necting with a wire cable so that there is 

 never any trouble through having too 

 much play, or slack. 



Another piece of apparatus which is a 

 desirable adjunct' to the modern motor- 

 boat is the generator and magneto. These 

 magnetos are known as high and low 

 tension, the former being for ignition pur- 

 poses only, while the latter may be used 

 also for lighting purposes. In order to 

 overcome the objection of the Steam Boat 

 Inspection Service to this method of light- 

 ing, it is advisable to have a storage 

 battery connected into the lighting circuit 



