In some bows the octagonal portion, known as the handle (Fig. 38_d_) on which the nut travels has the lower face rather larger than the rest as in the section shown in Fig. 42. The object of this enlargement is to give the nut a broader surface to travel on and thus prevent the tendency to rock exhibited by some nuts. But, though there is some merit in the idea it has been found that the rocking can be avoided in a normal bow having the eight sides of the handle equal by extra care in fitting. And though the other pattern may be easier to fit in the first instance, the projecting sides of the nut that travel on the adjacent faces of the handle are very small and weak; consequently before long the nut shows longitudinal cracks at this part and becomes extremely rocky, though from a different cause. [Illustration: FIG. 42.] One of the most frequent repairs is the operation of re-facing. The handsome central gasalier of the modern room is a great enemy to the violin and seems to lie in wait for the peak of an unwary violinist's bow. Fortunately the damage is not very serious, and an experienced bow repairer will not be long in restoring the head to its original elegance of outline. CHAPTER XII. RE-LAPPING--RE-HAIRING--CHOICE OF ROSIN. The lapping frequently wears out and becomes a source of great irritation until one has an opportunity of having it newly done. For this reason a lapping of leather is the most convenient and economical, but nothing looks better than a good quality of silver cord, and when it is bound with leather just where otherwise it would suffer from the pressure and friction of the thumb nail it is really very durable. Messrs. W. E. Hill and Sons have an extremely handsome speciality in the way of lapping. This consists of whalebone, sometimes bleached or dyed, and is practically indestructible. Bound on in alternate strands of different colours it has a very effective and neat appearance.