When a Tourte bow is held at the frog and lightly tapped against the player's opposite palm, an evident vibration can be felt through the bow. Rarely in modern bows can this vibration be so clearly detected. It is one of the most significant of Tourte's many construction secrets. Giovanni Lucchi of Cremona invented a device for measuring the velocity of sound through solid materials and advocated its use in selecting wood for modern bows. Tourte's bows combined speed with two other equally important qualities, the regularity of their vibration and its long damping time. These properties give his bows the ability to express the harmonic series without distortion and to couple the bow's regular vibration to that of the instrument. Tourte's bows draw an instrument into fuller and more harmonic vibration than other bows do, enhancing its positive tonal properties and projection while minimizing its distortions.
The materials currently used in Ervin bows are selected for their unique contributions to the final product. The wood favored by Tourte was pernambuco from Brazil. Most modern supplies of this wood, when they were still available, were from frequently-harvested stands. Tourte had access to old growth pernambuco of greater density and finer grain than the modern supplies. Dr. Ervin was one of a few American bowmakers fortunate enough to purchase wood from the De Almeida Ranch in Pernambuco Province prior to the Brazilian government's ban on exportation. That wood had never been harvested before the 1980s and provided the finest old growth pernambuco to reach the market in decades. In addition to testing the wood with a Lucchi meter, Charles further tested the wood for regularity and length of vibration, selecting only those pieces which passed all three tests.
To this choice wood he currently adds fittings made from stock provided by Bogaro and Clemente of Italy, a firm specializing in the highest quality materials. Dr. Ervin custom finishes and fits their frogs and buttons to his De Almeida bows. Their advantages are lightness of weight, accuracy of construction and beauty of materials. As weight is a significant factor in making a well-balanced and comfortable bow, one which vibrates as fully as possible, every gram saved is important. These fittings are of thin-sheet rose gold, inherently lighter than yellow gold. The ebony used is fine-grained and very dark, more attractive and stronger than most ebony available today. They also use a rare type of mother of pearl that is the most beautiful Dr. Ervin has ever encountered, a beauty he wants to share with his customers. It most closely resembles fire opal, with a universe of color shining in every piece.
Dr. Charles Ervin represents the great tradition of Cremona at its highest level. His knowledge of restoration and adjustment enhances the qualities of Stradivarius, Guarnerius, Gaspar da Salo, Amati and all the elect of quality makers.
Professor of Cello and Chamber Music,
University of Texas at Austin
Solo Recording Artist with the English Chamber Orchestra,