26th May | 1861
My dear Sir,
Mr Derffel2 formerly assistant professor of physics and mathematics under Petzval3 at Vienna now earning his bread in England as a teacher of music in which he is eminent as a composer and performer is anxious to obtain cards of admission to the lectures at the Royal Institution on the Friday evenings.
As a scientific foreigner if this privilege could be accorded to him I should be much obliged by your obtaining it for him. He is an excellent mathematician to my certain knowledge. William Francis whom you well know was the person who originally introduced him to me. If you are able to comply with this intercession, you would perhaps be kind enough to furnish him with the means of admission by a communication made to him—direct at his lodgings 23 Queen St May Fair. Englishmen are well treated by their scientific friends abroad. I am sure you will agree with me that we ought to endeavour to return in kind the liberality we meet with especially in the case of a man like Derffel thrown out of his proper sphere by an adverse current of circumstances.
Believe me | Yours very truly | J. J Sylvester
RI MS JT/1/S/291
RI MS JT/1/TYP/4/1508
James Joseph Sylvester: (1814–97), professor of mathematics at the Royal Military Academy at Woolwich from 1855–70.
Mr Derffel: Joseph Derffel (1823–84), pianist, composer and physicist. Formerly a private lecturer of higher mathematics and physics at the Polytechnic School of Vienna, before becoming assistant professor of physics and mathematics at the University of Vienna. Derffel resigned from this position to follow his interest in music. He left Vienna for England, where he became a well-known pianist and composer (Niederrheinische Musik-Zeitung, 13 (March 1865), pp. 69–70).
Petzval: Joseph Petzval (1807–91), Professor of Mathematics at the University of Vienna from 1836–77.
Please cite as “Tyndall1785,” in Ɛpsilon: The John Tyndall Collection accessed on