ON FOG SIGNALS. 105 
a contrivance for viewing the incandescence produced in exterior darkness ; 
and several absorbents, partly for the sifting of the incident beams, and partly 
for the intercomparison of the transmuted rays with the incident. 
Report of the Committee on Fog Signals. By the Rev. Dr. Rozrnson. 
Turs Committee, consisting of Dr. Robinson, Professor Wheatstone, Dr. Glad- 
stone, and Professor Hennessy, was appointed at Manchester “to confer as to 
experiments on fog-signals, and to act as a deputation to the Board of Trade 
in order to impress on that body the importance of inquiries on the subject.” 
The matter was discussed by them at several meetings of the Committee, 
both in reference to what is practically known of it, and to methods which, 
though yet untried, seem to promise better results than any now in use. After 
mature deliberation, in which they have to acknowledge the valuable aid of 
Admirals FitzRoy and Washington, it was considered most advisable to embody 
in a Memorial to the President of the Board of Trade the facts which we had 
collected, to point out how defective is our knowledge of many things con- 
nected with the efficiency of these signals, and to indicate the nature of the 
experiments which are necessary to complete that knowledge. 
In accordance with this decision, I drew up the following Memorial, which, 
being approved of by the other Members of the Committee, was forwarded to 
the Right Honourable T. Milner Gibson, M.P., on June 18, 1863. 
Memorial. 
“‘Srr,—In consequence of an application from the Belfast Chamber of 
Commerce and several of the leading merchants of that important city, re- 
questing the British Association to cause experiments to be made with a view 
to determine what kind of signals are best for indicating to sailors in foggy 
weather the vicinity and position of a danger, that body, after careful delibe- 
ration, came to the conclusion that, from the momentous bearings of such an 
inquiry on the preservation of property and still more of life, it ought to be 
regarded as of national importance, and as such was a fit subject for investi- 
gation by the Government. 
“Tt therefore appointed a Committee, consisting of 
Rey. T. R. Robinson, D.D., F.R.S., Chairman, 
Charles Wheatstone, F.R.8., 
J. H. Gladstone, Ph.D., F.R.S., 
H. Hennessy, F.R.S., 
and directed them to bring the matter under your consideration,—to point out 
the defects of the existing fog-signals, and to express a hope that under 
your auspices some methods may be devised which will, if not entirely 
remove, yet greatly diminish the chance of such fearful calamities as that 
which within the last few days has spread sorrow through the land*. 
“ Nearly all that is known about fog-signals is to be found in the Report 
on Lights and Beacons; and of it much is little better than conjecture ; its 
substance is as follows :— 
“Light is scarcely available for this purpose. Blue lights are used in 
the Hooghly; but it is not stated at what distance they are visible in fog: 
their glare may be seen further than their flame. It might, however, be 
desirable to ascertain how far the electric light or its flash can be traced. 
‘Sound is the only known means really effective ; but about it testimonies 
* The loss of the ‘ Anglo Saxon,’ with most of her crew and passengers, in a fog. 
