This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
The young oarsman is apt to experience difficulty in keeping a straight course until he has had some practice. Rowing a boat in a narrow channel calls for considerable skill to hold a course in mid-stream. A variation of force in pulling the oars almost instantly results in the rowboat making a landfall on one or the other of the banks.
The skilled oarsman does not need an appliance that the beginner might welcome. With the aid of a mirror conveniently supported at a suitable angle and height before the oarsman's face, the water, the shores and approaching boats may be seen with distinctness. The mirror may be set directly in front or a little distance to one side as shown in the sketch. - Contributed by Thaleon Blake, Sidney, O.
Ill: The Mirror Attached to a Boat