Guernsey.
_Photographic Experience._--The plan proposed by DR. MANSELL, in the last
Number of "N. & Q.," for comparison of photographic experiences, will, I am
sure, prove of much practical advantage and I therefore lose no time in
filling up the table published in your paper:
1. Eight minutes' exposure.
2. South Wales.
3. Mr. Talbot's original receipt.
4. Turner.
5. 3/8 inch.
6. 2 inches.
7. 3 inches. Focal length, 17 inches. Maker, Ross.
I would also suggest that the character of the object copied should be
included in the above table. My answer supposes a light-coloured building,
of an ordinary sandstone colour. A view comprising foliage would require a
much longer time for its full development. In working on the sea-coast, I
find that the dark slate rocks of north Cornwall require an exposure in the
camera half as long again as the blue mountain limestone cliffs of South
Wales, which abound in actinic power.