Finished a set of whistles the other day using a new material, well new to me anyway. In fact it's a very hard vulcanised rubber, dating from 1839, which was used for all sorts of purposes, including flutes, in its day.
Rockstro, he of "A Treatise on the Flute "fame, was a keen advocate of the material:
Ebonite embraces more good qualities than any other material ever used for the manufacture of flute tubes. This valuable and well known compound, often called vulcanite, consists of India -rubber, sulphur and lead, mixed with a black pigment and subjected to great heat. Its first employment in the construction of flutes is not of recent date, for in the great exhibition of 1851 I saw one that was made of it. This was however, but a very rude instrument and it attracted little attention. About twenty years afterwards Messrs Rudall, Rose Carte & Co. undertook the manufacture of ebonite flutes, and these instruments are now more popular in England than any others. If we compare the qualities of ebonite with the list of requirements of a flute-tube, we shall find that it leaves little to be desired.
Firstly, then in the matter of endurance it may be pronounced perfect for it is practicably indestructible.
Secondly, as it is absolutely non-absorbent of moisture no change in the dimensions of the tube ever occurs, and a metal head-ling is unnecessary.
Thirdly, an ebonite flute invariably improves by judicious use.
Fourthly, this substance possesses just the amount of rigidity necessary for the retention of the enclosed air-column in its proper shape and dimensions, while its own vibrations sympathise so readily with those of the air within, that the sound is produced with as little expenditure of the breath as on a metal flute. This latter circumstance renders ebonite flutes particularly suitable for the use of ladies, and for whom none is better adapted. The excellent and brilliant performer Miss Cora Cardigan ( Mrs. Louis Honig ), known as the "Queen of Flute-Players," always plays on an ebonite flute. The charming quality of the tone that this talented lady elicits from her instrument is too well known to need any panegyric in these pages.
Fifthly, this material is so bad a conductor of heat that ebonite flutes are far less affected than any others, in their pitch, by alteration of temperature.
Sixthly, its appearance excels that of the finest ebony, and it generally retains its original lustre with very little attention, though sometimes it loses its extreme blackness.
The practical consequences of all these theoretical perfections is that a flute made of ebonite possesses great endurance combined with capabilities for producing power, softness, volume, brilliancy, sweetness, clearness, flexibility, and general variety of tone, in a greater degree than one of any other material, a slight reservation being necessary in the case of the single quality of power, and if this is a trifle less than that of a cocus wood flute with metal head-lining, the other advantages so immeasurably outweigh the exceedingly slight inferiority in this respect, that ebonite must be pronounced the veritable beau ideal of the material for the tube of a flute.
Not sure that I agree with all of that, (especially the length of the last sentence!), and it would make one wonder if Rockstro had a commercial interest in ebonite. It is a useful material though, and the samples I was sent by Schonberger Ebonite I've been experimenting with. First attempt is the whistle heads, which look great. ( I think anyway ). Here's a couple of pics:
At this stage the plug, which you can't see in this photo, is still delrin, but I've been modifying the brass pin which keeps everything together, so that it's pushed into place and held there by friction.
This enables me to make each end slightly domed and polished, and makes a much simpler job of tuning the outside of the head to an even, cosmetic, finish.
I'm considering making a post mounted flute from the black sample I've received.
I'll keep ye posted...