244
THE ESSEX FIELD CLUB.
they had been used as "pot-boilers" or for other purposes. Mr. Warren
detailed a successful experiment, which he had himself made, to boil
water by dropping heated flints into cold water, and remarked that a
similar method is adopted in Japan to obtain steam-baths.1
The exhibit called forth considerable discussion, in which Messrs. Cole,
Shenstone, Thompson, Christy and Prof. Meldola took part.
In reply to various points raised, Mr. Warren stated that the "hearth"
referred to lay close to the junction of two streamlets, only a few yards
from either ; he thought that the site was quite possibly a "potash-floor,"
and he had not formed any opinion as to a possible connection with the
neighbouring Loughton camp.
Mr. Warren also reported that, at Walton-on-Naze last Christmas, he
had seen boys picking up "copperas" which, they informed him, was
ground up in the Walton Tidal Mill and sent away.—Mr. Miller Christy
remarked that the "copperas" industry had entirely ceased in Essex for
30 years past, so that he could not understand for what purpose these
stones were now being gathered.
Mr. B. G. Cole sent for exhibition a set of specimens of the Peacock
Butterfly (Vanessa io) variety cyanostica (Raynor) bred from caterpillars
taken at St. Osyth during the last summer.
Papers Read.—Mr. H. Whitehead, B.Sc., on behalf of himself and Mr.
H. H. Goodchild, read a paper entitled "Further Notes on Moorlog, a
Peaty Deposit from the Dogger Bank," supplemental to his previous
communication published in the Essex Naturalist (vol. xvi., pp.
51-60). The paper was illustrated by lantern photographs and maps.
Mr. D. J. Scourfield, F.R.M.S., followed with a verbal account of the
Entomostraca he had identified in the washings from the peat sent him for
examination. He stated that these amounted in all to some 18 species,
nearly all Cladocerans. No Copepods occurred, and very few Ostracods,
one form only (a Cytheridea) being a brackish-water species ; all the rest
were fresh-water forms.
An interesting discussion followed, carried on by Messrs. Warren,
Thompson, McLachlan, Dalton, Nicholson and Dr. Graham, and Mr.
Whitehead replied to several enquiries made.
The President proposed a vote of thanks to the authors, which was
heartily carried.
Mr. C. Nicholson read "Notes on Plusia moneta in Britain" and
exhibited specimens and photographs of the moth and its cocoon ; following
which Prof. R. Meldola, F.R.S., and Mr. W. Cole added some further par-
ticulars regarding the occurrence of the moth and some of its near relations
in Essex and elsewhere.
The thanks of the meeting were accorded to Mr. Nicholson for his
paper.
Owing to the lateness of the hour, it was decided not to read the Rev.
W. K. Wyley's communication, entitled "A note on some Ichneumon-
1 It is stated in Johnson's Folk-Memory (1908), pp. 112-13, that the use of the Pot-boiler was
continued until late in the historic period. "Linnaeus, whilst making his Northern tour, saw
the inhabitants of Bothland brewing beer in this way. And at the present time the Austrian
peasant drinks such beer, which he calls 'stone-beer.'" (Ed.)