William Havell¹ to Faraday   23 March 1839

March 23d. 1839. 24 Montague St | Portman Sq

Dear Sir

From the interest you showed last night in explaining my application of Photogeny to the art of multiplying designs, by means of a drawing, painting, or etching on glass², I am induced to state more in detail the various processes by which these objects may be more effectively obtained, it having been impossible last night to embrace such a variety of topics.

The subject on the large glass is Faust raising a spirit in the appearance of a bright star, was hastily sketched from an etching by Rembran[d]t³, by merely laying the glass on the print, painting on the lights with opaque white lead, combined with copal varnish & sugar of lead to make it dry quickly - semiopacity of the same colour represents the middle tints: when these were perfectly dry the whole was retouched be removing portions of the colour with the point of a knife or etching point. While this was exposed to the Sun, I perceived the middle tints were not sufficiently opaque to resist the light, this obliged me to resort to the use of black paint on the clear side of the glass[.]

This is of great importance as it answers to the practice of engravers in stopping out when a plate is bitten too fast by the acid. There is no advantage in letting the glass remain too long in the light, as it deepens the middle tints & does not blacken the shadows in the same proportion. The specimen sent was exposed too long. The other trifle "a man reading", was done by the above mentioned process. The progress of the work is best seen with the glass laid on a black surface. These specimens were produced immediately after Mr Fox Talbot's disclosure of his process Feb 25th 1839⁴. I was so much dissatisfied with the transfer of points which blackened the lights, that I invented a method of turning this defect to account by throwing the black into the shadows. The subject of two heads after Guercino⁵ was produced by my suggestion to my brother Frederick James Havell⁶, to show an etching ground on glass, & removing the same by the etching point, the effect may be heightened by applying Fluoric Acid to various parts. But the most pleasing mode of etching is by a white opaque ground, similar to the enclosed specimen, & laying the glass upon a black surface, it resembles a sketch with a pen & Ink - bright lights may be effected by touching on the other side with black paint.

It is quite clear that artists may by considering the above methods, multiply original sketches or designs, ad infinitum, they never wear out, may be altered, improved, retouched at pleasure, requiring no printing presses, any number may be exposed to the light at the same instant[.]

There are many other applications of Mr Fox Talbot's invention which readily suggest themselves such as the transfer of engravings. The best method is as follows - Transfer an engraving upon glass by means of Venice Turpentine & damping the points; The oily black lines will only adhere, & the paper may be rubbed off by which means an intense black will be obtained upon Photogenic papers with a sharp relief of white lines - these may be heightened by deepening the black with water colours & scraping away the paper in the white lines with a sharp pointed knife, then stick it to a glass & it is ready for Photogenic transfer upon the sensitive paper.

A few other suggestions readily occur, such as multiplying circular letters by reversed writing upon glass, upon a black or white opaque ground. Blocks of types may be transferred by sticking them down to glass with gum & pouring on a blackened varnish. This after drying the types will remove by moisture[.] The letters BPD &c must have little holes drilled into them &c. These last I have not tried, but there can be no doubt that any one may print his own manuscript book with unlimited illustrations without the aid of Printer's & Engraver's or Presses. Only one side of the paper can be employed. This may be very important where such small numbers may be required as not to be worth the expense of employing the Printer or Engraver, but it is very doubtful if it can ever rival the utility of the former or the beauty of the latter. I have taken the liberty to occupy your attention to these statements as these suggestions originated with me, & being communicated last week by my brother Frederick to others, has been the cause of an attempt to ensure a patent for an improved method of printing & multiplying designs &c &c this has been found impossible & was never thought desirable on my part. I believe it is now relinquished. Should you think these statements worthy of publicity I shall be obliged by their being inserted in any account of public transactions with any omissions, alterations or amendments you may think proper. I have just heard there is an incorrect report of the proceedings of last night, published in the Literary Gazette⁷[.]

I am dear Sir | Your obliged humble Servant | Wm. Havell