In setting the hinges of a box cover, first see that the cover fits the box exactly all the way around.
In the case of a door, see that it fits its frame, evenly all the way around, but with a little play. To insure a tighter fit at the swinging edge this edge should be slightly beveled inwards.
In attaching a butt-hinge, the essential thing is to sink the hinge into the wood, exactly the thickness of the knuckle. The gains may be cut in one or both of the pieces to be hinged together.
With these matters determined proceed as follows: In the case of a box cover, the hinges should be set about as far from the ends of the box as the hinge is long.
In the case of an upright door, locate the hinges respectively above and below the lower and upper rails of the door. Mark with the knife on the edge of the door the length of the hinge, and square across approximately the width of the gain to receive it. Do this for both hinges. Between these lines gage the proper width of the gains. Set another gage to one half the thickness of the knuckle and gage on the door face the depth of the gains. Chisel out the gains, set the hinges in place, bore the holes, and drive the screws. Place the door in position again to test the fit. If all is well, mark the position of the hinges on the frame, gage and cut the gains, and fasten in the hinges. Where the hinge is gained its full thickness into the door, no gain, of course, is cut in the frame. If the hinges are set too shallow, it is an easy matter to unscrew one leaf of each and cut a little deeper. If they are set too deep the screws may be loosened and a piece of paper or a shaving inserted underneath along the outer arris of the gain.