Item 41 - Letter from John Herschel

JH will be happy to see Mr. Bunt's [Thomas G. Bunt - based in Bristol and took most of WW's tide observations along the South-West coast] Planetarium. Could WW bring it to his new home in Hawkhurst, Kent? JH is getting no end of strange results from his photographic research: 'I have now got papers which when half darkened darken more at the red end of the spectrum and whiten at the violet - others which darken far beyond the visible end - others which darken at the first impression of the light and then whiten - some which whiten at the two ends of the spectrum and darken in the inside etc'.