CORRESPONDING SOCIETIES OF THE BRITISH ASSOCIATION. 127
to be especially numerous and powerful, if Palaeozoic rocks are
unusually near the surface there, a view to which I am myself
inclined. It would be interesting to compare with the record of an
instrument so placed, that of another at Culford, near Bury St.
Edmunds, where Palaeozoic rocks of doubtful affinities have been
found at a depth of only 6371/2 feet below the surface. And it is
evident that others are also desirable in districts where the earth-
quake was unfelt, and where Palaeozoic rocks (as near Battle, in
Sussex) are known to be at a great depth below, for the sake of
comparison with the results attained in differently constituted areas.
Pollution of Air in Towns.—Dr. G. H. Bailey gave some account
of the examination of the air of towns in which they had been
engaged at Manchester, in connection with the Manchester Field
Naturalists. He had come to the conclusion that the amount of
the death-rate varied with the amount of the pollution in the air.
The diminution in the amount of sunlight or daylight in the
centres of large towns, as compared with their suburbs and with
the open country, might amount to fifty, sixty, or seventy per cent.
The work already done had been chronicled in the "Journal" of
the Manchester Field Naturalists for 1893. As regards the effects
of smoke on plants, the Chairman (Professor Meldola) remarked that
cryptogams and lichens were once common on trees in Epping Forest
though now they are rare.
Mr. W. Whitaker, F.R.S. (representing Section C), said that the
first subject to which he would refer was Coast Erosion. The final
report on this subject would be made next year, and the matter
would then be handed over to the local societies, when those which
had coast lines could register future changes on six inch maps.
The Committee dealing with the Circulation of Underground
Waters would also issue their final report next year, and the local
societies would be able to continue the investigation. Twenty
reports had been issued, and it had been suggested that if the
material in them were arranged topographically, and possibly
condensed, many local societies might be glad to have the volume,
which would probably form an octavo book of 250 to 300 pages.
Professor Blake wished to inform the representatives of the local
societies that he was engaged in examining the microzoa of clays,
especially of Jurassic Clays, and would be much obliged if they
could send him samples. He would be glad to report to the senders
as to the general character of these clays and their microzoa. He