Sometimes the ordinary thread lapping gets cut through and interferes with the player, and it is as well to know how to fasten it off at once. I will assume that it is cut at the end nearest the nut (where it usually happens). Take out the screw and wind the hair loosely but securely round the upper part of the bow. Then unwind the lapping for about an inch and a half. Take a piece of strong thread and double it, then place it on the bow with the doubled end towards the handle. Get a kind friend to hold the end of the lapping cord firmly and commence winding it on again evenly and _over_ the doubled thread by slowly rotating the bow. When within half an inch of the end of the thread, take it all in your own hand and pass the end through the loop of doubled thread and, taking the loose ends of the thread that will hang out at the point where you started re-winding, pull the doubled thread smartly out. This brings the end of the lapping right through under the re-wound portion, where it will be held secure until again cut through by the thumb-nail. This is the method employed in fastening off new lappings. If you have not the time or patience to do it this way a little sealing wax will hold the loose end down during an evening's practice. Considering that re-hairing is one of the most natural and most frequent events in the life of a bow, it seems somewhat anomalous to include it under the heading of "repairs." However, I will crave the reader's kind indulgence for so doing. At the outset I must emphatically assert that I do not advise amateurs or artists to attempt to hair their own bows if any value attaches to them, for it is astonishing how soon even a fine bow will lose its _cambre_ if persistently haired in an unskilful manner. It requires enormous experience to enable one to get the pull of the hair equal in every case, and the slightest extra pull on one side or the other gives the bow a twist that renders its action erratic and extremely disturbing to a good violinist. The preceding operation to re-hairing is that of unhairing. This is comparatively a simple matter. The hair is first cut off short at each end, then hair at the head is lifted up to disclose the plug (Fig. 40_a_). This is readily lifted out with a pointed tool, and the curled up knot lying beneath is pulled out. So much for the head. The nut is slightly more complex. First the ferrule (Fig. 41_d_) is pulled off and the slide (Fig. 41_f_) is pushed out. After this the hair is raised as with the head, and the plug (Fig. 41_e_) picked out in the same manner. The wedge in the nut (Fig. 41_c_) is used to spread the hair and keep it firm at the heel, to give a good attack for heavy down strokes. This is usually destroyed in unhairing, as it frequently has to be cut away, owing to its being glued into position.