131, p.

84, and glued in place.

If pains are taken to match the grain, the scar thus formed is inconspicuous.
In rough work, the screw may be driven into place with a hammer thru most of its length, and then a few final turns be given with a screwdriver, but this breaks the fibers of the wood and weakens their hold.

In "drive-screws," Fig.

229, e, the slot is not cut all the way across the head, in order that the blows of the hammer may not close the slot.
The advantages of screws are, that they are very strong and that the work can easily be taken apart.