From Francis Hopkinson, with Enclosure
Phila. May 25th. 1784
Enclosed you have my Proposals respecting the improved Method of Quilling a Harpsichord; these may be shewn to any Instrument Maker, and in Case he will engage to allow a reasonable Recompense for the Invention, if the Engagements therein made shall be fully answered. The Paper containing the Description (or a Copy of it) together with one of the Models in the little Box herewith delivered may be given to him, which will enable him to comprehend the whole Device, and to execute it in a better manner than I have done.
As to the Quantum of the Recompense I leave it entirely to your better Judgment and freindly Determination. I should however suppose that if the Improvement answers the purposes expected, it is worth 30 Guineas if it is worth any thing.
Should you have any Success in this Negociation, my Wish is that you would pay to Dr. Franklin my Subscription to the new Encyclopedia; and with the Remainder of the Money (if any) purchase a few Yards of handsome grane1 Silk sufficient for a Gown or Robe for Mrs. Hopkinson. If there should be still a Remainder, send the Amount in Sets of the best Crayons or Pastiles, with a Quantity of black and white Chalk. These I can sell to advantage.
I had need make many apologies for giving you so much Trouble. But as I know I would chearfully do ten times as much for you, I feel the less Reluctance.
With sincere Wishes for your Health and Prosperity I am Your affectionate friend & faithful Humble Servant,
I wish you to shew the Description and models to our friend Dr. Franklin.
Description of an Improvement in the Manner of Quilling a Harpsichord or Spinnet
Philada May 24th. 1784
The present Mode of quilling a Harpsichord is subject to this great Inconvenience, that some of the Quills, will after a little Use, crack, and loose their elastic Spring, whilst others retain their full Vigour, thereby rendering the Touch unequal, and some Tones full and loud whilst others are so faint and weak as scarcely to be heard. The different Gradations of Strength from a Quill absolutely broken to one in full Strength are so various and imperceptable that the most nice Attention cannot restore the perfect Equality which the Instrument had when it first came from the Hands of the Maker and even to keep the Harpsichord in tolerable Order, in this Respect, requires constant Examination and frequent Repairs. To remedy this, many Substances have been tried as Substitutes for the Raven Quill, but all without Success. They have all been found liable to the same Inconvenience, with this additional Disadvantage, that none of them could draw so pleasing a Tone from the String as the Crow or Raven Quill.
I have also tried many vain Experiments to remedy this Evil, but being always disappointed in my Search for a Substitute, I at last thought of examining into the Cause of the Quill’s being so liable to crack, the Discovery of which I hoped would suggest a Remedy, and was not disappointed in my Expectations.
The Quill, as applied in the usual Way, is worked to the greatest Disadvantage. See Fig. 1. Where (a) is the Tongue in which the Quill (b) is fixed, about one Quarter of an Inch in Length. In such Case the Quill is too short to admit of it’s bending freely and operating, as a Spring, which it ought to do; but when, by the Impulse given, it is forced to yield, it bends only (or at least principally) at (c) where it issues from the Tongue, working there as upon a Hinge; and this by frequent and rapid Movements must cause it to break in that Place. And it is observeable that there, and there only, does the Quill ever crack. A Peice of Steel if made to bend backwards and forwards frequently on one Point would also break. The Cause thus discovered, I thought if the Quill could be made much longer, and it’s bending be in a Curve, instead of on a fixed Point, it would operate fairly as a Spring, and retain it’s Elasticity for any Length of Time, as other Springs do.
For this Purpose I constructed the Tongue and applied the Quill as represented in Fig. 2. where (a) is the Tonge (b) the Quill, which is firmly fixed in the little Hole punched for it’s Reception, and then, by an even Pressure, bent over the rounded Top of the Tongue (c) is a small Wire Staple, necessary to cause the Quill to proceed in and retain a horizontal Position. This Staple should be driven down so as to bring the Quill very near to, but not absolutely pinch it against the Top of the Tongue; for, if it should, it would bring it back to the same disadvantageous Situation in common use. Without enlarging upon this Improvement, it is manifest from the Figure, but more particularly from the Model, that the Play of the Quill, or it’s Spring, being in the Curved Line (b) there is no particular Point on which the Stress is laid, no Place where it can possibly break, but will retain it’s Elasticity any reasonable Length of Time failing only by an actual wear of it’s Substance. It will also be more lively and pleasant to the Touch, and acting fairly as a Spring, will draw a more free and a purer Tone from the String.
This Method of Quilling will require the Quill to be stronger, than in the common Way; it must be very firmly fixed in the little Hole and the Tongue should be scraped gradually thinner from the place where it issues from the Tongue to the Extremity of the Point. The Use of this Caution is to prevent any Chance of Motion at the Place where it issues from the Tongue, for if there should, it will probably, in Time, crack in that Part.
Should the Quill be dry and hard by long keeping it will be proper to dip it in hot water before it is applied, in order to make it more easily take the intended Curve, without breaking.
It may be a further Improvement if instead of the Quill’s being inserted horizontally into the Tongue thus [see Fig. 3 in margin] it could be fixed in a hole slanting downward thus [see Fig. 4 in margin]. The Quill would then be less forced in it’s Bent, and be in no Danger of coming out.
Much more might be said on the Subject, but actual Experiment must, and I trust will, confirm the Reality of the Improvement.
RC (MHi); addressed: “Honble Mr. Jefferson.” Enclosure is in MHi.
On Hopkinson’s method of quilling a harpsichord, see Hastings, Hopkinson, 342–3 and Hopkinson to TJ, 18 Nov. 1784, with its enclosure of a paper for the American Philosophical Society. Shortly after TJ received the letter of 18 Nov. 1784, he drafted an advertisement of Hopkinson’s invention for publication in a newspaper, and in that utilized the first paragraph of the present text of the “Description of an Improvement,” &c. (see under Feb. 1785 and also TJ to Hopkinson, 6 July 1785).
1. It is possible that this may be “greene silk,” but the reading above seems more likely, meaning, of course, grosgrain.