TALBOT2706

Answd May 30 1833 ¹

29 Albemarle S^{t 2}
May [28^th? 29^th?] ³1833

Dear Sir,

I do not know whether you are likely to be in Town again during the next 3 weeks, but if you are, I should like to show you an experiment on Newton’s rings ⁴ which appears to me to be very remarkable. By causing 2 of these rings to interfere, I obtain a vast number of parallel coloured bands at right angles to the line joining their centres, but the most singular thing, and affording a beautiful illustration of the Theory of Interference, is, that by holding the hand in a particular way so as partially to intercept the incident light, the dark part of the rings suddenly become bright, & the bright rings become dark, the colours changing in to such a degree as to give the system of rings a completely new appearance.

I should wish to communicate some account of this to the Royal Society, but am afraid of falling into the error of giving as new what may be already known. I should therefore be much obliged to you if you would inform me whether the conversion of lights into darkness & vice versâ in Newton’s rings has been anywhere described, & also the appearance of the parallel fringes that I have described at the beginning of my letter.

Believe me Dear Sir Yours vy truly
H. F. Talbot