[Transcriber's Note: To see a larger version of this image, click [here].]

Fig. 231.

Now turn the boat bottom side up and nail the bottom on, as already described in previous chapters ([Fig. 232]). The bottom-boards are to be so planed upon their edges that they leave V-shaped grooves on the inside of the boat to be calked with candlewick and putty ([Fig. 231]). Next make a shaft-log by cutting a board in a triangular piece, as shown in [Fig. 233], and nailing two other pieces of board on it, and leaving a space for the shaft-rod, over which is nailed a duplicate of the bottom-board, as shown in [Fig. 234]. Make the shaft-log of three thicknesses of 1-inch plank. To make it more secure there should be a board nailed on the inside bottom of the boat, as shown in [Fig. 235] by the dotted lines.

This board is put there to strengthen the bottom and allow us to cut a slot through for the admission of a shaft ([Fig. 236]) which is drawn on a scale shown below it. With the engine comes a stuffing box, through which the shaft passes and which prevents the water from coming up through the shaft-hole. The stuffing boxes, which are furnished to fit upon the inside of the boat, are expensive, but one to fit upon the stern of the shaft-log costs but little, and will answer all purposes.

Of course, when attaching the shaft-log to the bottom, it must be in the exact centre of the boat. Find the centre of the boat at the bow and stern, mark the points and snap a chalk-line between them. Now place the shaft-log in position on this line and while holding that there firmly, mark around it with a carpenter's pencil. Next lay the shaft-log flat on its side with its edge along this line and with your pencil mark on the bottom of the boat the exact place where the shaft-hole must be cut to correspond with the one in the shaft-log. As may be seen by [Fig. 236], the shaft runs through at an acute angle; hence the hole must be bored on a slant, or better still a slot cut through the floor long enough to allow for the slant.