Driving Screws
A wood screw having the threads hammered flat on two sides can be easily driven in with the flattened sides parallel to the grain of the wood. When the screw is turned a quarter turn the remaining threads cross the grain and hold as well as if they had been turned in all the way. This is an especial advantage where something is wanted which is easily inserted and will hold better than a nail.—Contributed by P. D. Merrill, Chicago.
A Power Windmill
The windmill shown is somewhat different from the ordinary kind. It is not a toy, nor does it approach in size the ordinary farm windmill, but is a compromise between the two, and in a good strong wind, will supply power enough to run a washing machine, a small dynamo, an emery wheel, or any other device used in the home workshop. The wheel is about 5 ft. in diameter, with eight blades. The over-all length is about 6 feet.
The windmill is easily made and the cost is within the means of the average boy. There is not a part used in its construction that cannot be found about an ordinary manual-training shop. The most difficult parts of the construction will be described in detail. Symmetry and smoothness of design should be preserved and the parts made as light as possible consistent with strength and durability.
The Hub Consists of Two Parts, Each Having Four Arms for Holding the Blades (Fig. 1)