CELLO BOW CAMBER

At this stage the camber has been finalized and the stick, which has been octagonal up to this point is rounded. The taper of the stick and its curve or camber is critical to how the bow will play and sound. Because of the power needed to drive the large diameter cello strings the bow must be far more resistant than a violin bow. On the other hand there is an incredible range of expressivity to the cello’s sound and without flexibility the cellist cannot access this potential. Yet there is no consensus between bow makers as to what will work best and this is for good reason because there is no consensus between fine players either. I have measured bows belonging to a number of today’s great players and they vary in every way; weights ranging from 76 to 90 grams and widely ranging camber concepts and stick graduations.

The bow maker can approach commissions it two ways. One is to simply do what they think is best and the players who like these bows will buy them. The second to tailor the bow specifically to the player but in this case one inevitably has ideas on how to reach this goal. Although I’m in the later group, the solution is not to simply copy the bows a player has. If they want another bow its because they believe they can unlock more potential from their instrument or their technique with a different stick. It is possible that something quite different would be ideal for them if they can make the technical adjustment. They have no doubt tried certain bows belonging to colleaugues that they loved. If it was a well-known maker like Dominique Peccatte or Eugene Sartory, that gives us quite a bit of information up to a point because each of these maker’s work also varies considerably. In the end the maker has to make an intuitive call on the camber, stick selection and graduations or taper that he hopes will give his or her client all the power and potential for expression they need. There is a kaleidoscopic interchange of different elements that effect the hoped for outcome, a bow that joins both power and technical response with the flexibility to bring out the full spectrum of a cello’s sound.

PLANING THE STICK

The cello bow progresses and the stick is getting planed down to rough dimensions. At this time the frog is fit on the stick so that we can adjust the stick with the frog in place.

TALON

The silver heel plate or ‘talon’ is about half a millimeter in thickness and it is fit in a shallow channel cut with knife and chisels to accommodate it. When the silver heel is fit and bent into place, the forward edge is squared perfectly straight across where the pearl slide must join it perfectly. Then it is glued and riveted with small silver pins.

At this point the dovetailed channel for the pearl slide is completed and the mortise and channel for the hair is cut freehand using different chisels. The pearl slide or ‘recouverment’ is then fit and trimmed so it fits perfectly on all sides. Finally the bottom of the frog and the heel is filed so all parts are flush with the ebony and smooth. The pins, which have been left proud, are filed off at this time and usually disappear. The pins on a new bow are tight and very difficult to see but over time the miniscule movements of the ebony frog due to changes in humidity rock the pins slightly. So in older bows the pins are usually noticeable.

The frog is now well advanced and all that remains is the underslide or ‘coulisse’ where the frog joins the stick. Here a silver lining is usually fit and pinned in place and a bronze eyelet screwed into place. At this point the frog is complete and ready to mount on the stick but the polishing will wait until the bow is nearly completed.

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.