no doubt risk the safety of the boiler; but in the case of so-called
"distilling" ships, there need be no trouble incurred on this
score.--_The Engineer_.

* * * * *




AIDS TO CORRECT EXPOSURE ON PHOTOGRAPHIC PLATES.

[Footnote: We take from the Br. Jour. of Photo. the following interesting
paper read by W. Goodwin before the Glasgow and West of Scotland Amateur
Association.]


With good plates, and intelligent development, a practiced photographer
may within certain limits correct the effects of an over or under
exposure; but you have all, doubtless, found out that there is a correct
exposure, and that you cannot trespass very far on either side of it
without sacrificing something in the resulting negative.

MR. W.K. BURTON'S TABLE OF COMPARATIVE EXPOSURES
------------+--------------------+-------------------+-------------------------
| | Badly lighted| Portraits in bright
| | interiors,| diffused light
Aperture | +------------+ up | out of doors.
calculated | Landscape with | Fairly | to | /
on the | heavy foliage in | lighted | | / Portraits in
standard | foreground. | interiors | | / studio light