CELLO BOW

A cello bow is now in process and as with the violin bow we make the fog first. This is because the frog needs to ready to mount on the stick very early on in the process. Since I covered the frog making process in earlier posts I’ll only cover what is unique to a cello frog. The cello frog has a rounded heel or ‘talon’ so this necessitates a different approach in that area. The amount of curve or radius of the heel varies quite a bit between bow makers and in general the earlier 19^th century bows have a bigger radius or are more rounded. There is an aesthetic and stylistic relationship between the curves of throat and the curve of the heel. Since the length of the flat area on the bottom of the frog determines the length of the pearl slide, the rounder heels have a shorter slide all things being equal. In this case our radius is relatively large. The tighter heel curve of late 19^th century makers like Lamy was a bit easier to make and made possible a longer pearl slide since the flat area on the frog was longer.

Once the frogs heel is rounded we fit the eyes in the frog sides and in this case we are using a eye ringed with silver or ‘grain et cercle”. . To receive the ring, a narrow groove is cut with a special drill bit, which cuts the recess for the pearl eye at the same time. Each bow maker makes these bits themselves to the requirements of their taste and style. Francois Tourte was probably the first to make this type of eye and to begin with the ring was fairly heavy, getting finer during the course of the 19^th century. To make this eye a thin strip of silver is cut, bent into a ring and soldered. It is then put on a tapered rod or mandrel and hammered to the correct diameter. It is then filed until it fits snugly into its groove. The pearl eye is filed to fit and glued into its recess followed by the ring, which is hammered lightly into place. When the glue is set, any silver sitting proud can be filed off flush with the sides and the eye is completed.

EBONY. Beginning the frog.

There are many living things that go into a bow but after the Pernambuco wood, the bowmaker is perhaps most thankful for ebony. This amazing wood grows initially a creamy white in color before turning after some years to a black as dark as coal. So the sapwood or exterior inch or so of the tree trunk is white and the heartwood or interior of the tree is black. Over time the wood’s pores become filled with the minerals from the earth and when the wood is polished these minerals shine in little silvery lines. The polished wood takes a luster like marble.

Ebony wood refers to a number of different species in the genus Diospyros and only a few are suitable for bow-making with a jet-black color and a tight grain. The ebony of legend, Mauritius ebony or Diospyros tesselaria, has not been exported since the 19^th century. In fact it is exceedingly difficult to find ebony suitable for really fine bows. Years ago Stephane Thomachot and I bid for and won a lot of this ebony at the Drouot auctions house in Paris. It was from the estate of André Chardon and the crate, which had been stored in the coal cellar actually contained coal as well, which we dubbed ‘le charbon de Chardon’. Since that time it has been occasionally possible to locate ebony from Ceylon or Madagascar with the required qualities. A bowmaker needs only a very small quantity of ebony but nonetheless the conservation of these trees is of concern as the world’s forests are cleared. Replanting of the trees as we are doing with Pernambuco wood is necessary for the future.

The basic ebony piece that will become a frog is split or sawed from a larger block and worked down with a gouge and a plane. The minerals in ebony will dull a sharp tool in minutes so we have to sharpen often. When the blank is cut out we drill a hole where the ferrule will go and saw out the rough throat. Then we put the piece aside and prepare the silver for the ferrule.