439 
total dissolution of matter, is indeed very pretty ; but so many 
difficulties arise (however plain it may be to him). I believe few 
now-a-days are of bis opinion.” 
“ Above all, I think Mr. Petit’s liable to the fewest objections, viz., 
by the variation of the parallelism of the earth’s axis, which, being 
allowed, must certainly alter the centre of gravity : if so, all the 
lluid parts will conform thereto, and then it will follow that one 
part will be covered and overflowed by the sea that was dry before, 
and another be discovered and laid dry that was before over- 
whelmed.” 
Mr. Arderon sends a description of some large subterranean 
caverns in the chalk hills near Norwich, near Mousehohl Ileaih, 
which had been formed in a long series of time by the digging out 
of the chalk for the making of lime. “ There’s but one entrance into 
it, whose breadth is about two yards, and its height nearly the 
same ; however, the height gradually rises, till at last it measures 
in some places from twelve to fourteen yards. Notwithstanding 
the entrance is so small, the whole area within is of such large ex- 
tent, that twenty thousand men might with great ease be placed 
therein. In the very lowest parts of these vaults, I have picked 
up several kinds of fossils figured by marine bodies, such as echini, 
pcctunculi, common or fluted cockle, belemnitfe, &c., and by diligent 
search other sorts might be found. Sounds made beneath thesearched 
roofs are strongly reflected from side to side, so that the least 
whisper may be heard a considerable distance : the beat of a 
pocket watch was heard distinctly full twenty yards from where it 
was placed.” The temperature of these vaults are very equable, 
being about 52° by his Hawksbee thermometer. From a note to this 
paper, it appears that a terrible thunderstorm, on June 12th, 1748, 
shook the earth to such a degree as to throw down these chalk 
vaults. 
In the year 1746, the crops in Norfolk and Suffolk were seriously 
damaged by “ grubs or maggots, full as thick as a man’s little 
finger.” Mr. H. Baker applies to Arderon for information “ res- 
pecting the nature of this pest, which he imagines might be the 
aureliae or chrysalides of some species of Beetle.” Mr. Arderon’s 
reply is laid before the Royal Society, prefaced by an extract from 
a letter published in the ‘London Evening Post’ of Oct. 29th. 
(Arderou’s paper was read Nov. 5th.) This letter states that “ the 
