Oxford
Feb. 7. 1839
Dear Sir
I probably did not sufficiently explain myself in my last letter. I had long ago read your paper in the Phil. Mag. No ix <1> and it was in attempting to repeat your very curious experiment that I found myself unable to succeed & now therefore anxious for still further direction as to the method. As well as I recollect the way in which I tried the experiment was this: as you mention that the 2d prism has nothing to do with the reflected bands (which are there principally referred to) I used a right angled prism on a plate of glass, the plane light being admitted into a darkened room (not indeed wholly dark) through a lens of short focus & the prism being at about 6 feet distance – I could not however procure any such reflexion as to see the bands on a white screen &c. Perhaps you could be so kind as to inform me of any additional precautions which may be necessary.
It has struck me that there will one [sic] very interesting application of your “photogenic” experiments, <2> viz. (presuming that the effect depends on the deoxidizing property which is most powerful towards the violet end of the spectrum or even beyond it) to try the effect of the interference stripes on your prepared paper. <3> There ought I suppose to remain a series of stripes impressed upon the paper – and if so it would shew that this power (whatever it be) depends on the [illegible deletion] &c vibrations & disappears when they mutually destroy each other. Perhaps however you have already tried it.
With respect to the other topics alluded to in Your note no one can be more willing than myself to admit the existence of great & serious difficulties in the points referred to. <4> What I have mainly contended for is at once the impolicy & indeed impossibility of attempting to disguise or gloss them over – they will be forced on the notice of the world, & that in a hostile & mischievous spirit, if the friends of truth do not take up the subject & occupy the ground in the first instance so as to put the question in a fair & rational light. With regard to the particular ambiguity referred to of the (in p 260) the “narration” I allude to is both the shorter one continued in the 4h clause of the decalogue and the longer one in Genesis. i. It is clear the latter was written after the former. [illegible deletion]
The particular suggestion as to its being understood as rather a poetical mode of statement &c is not put forward as in itself supported by any particular arguments, nor is any stress whatever laid upon it. It is suggested merely as appearing to be the least offensive mode of stating [illegible deletion] the contradiction which exists, with reference to popular prejudices, & the prevalent, but as I think erroneous, notions of mixing up these subject with Christianity; which seems to me wholly independent of them.
Believe me to remain Very sincerely yours
B Powell
Notes:
1. WHFT, ‘Facts relating to Optical Science’, section 1 ‘Experiments on the Interference of Light’, Philosophical Magazine, s.3 v. 9 no. 56, December 1836, pp. 401–403.
2. Experiments on the art of the photogenic drawing.
3. Whether ‘the bands of colour produced by interference of Solar Rays’ could be photographed. [See Doc. No: 03808].
4. Probably alluding to Baden Powell, Tradition Unveiled; or, an exposition of the pretensions and tendency of authoritative teaching in the Church (London: 1839); an attack on the followers of Edward Bouverie Pusey (1800–1882), theologian. [See Doc. No: 03790].