236 TRANSACTIONS OP THE PLYMOUTH INSTITUTION. 
two inches wide, and two inches deep, similar to the small cavities 
already noticed in one of the mould stones at Gobbett. 2 The 
perfect cavity is twelve inches long, three inches wide, and three 
inches deep, and appears to be similar to the cavity found by the 
late Mr. Kelly, and mentioned by that gentleman in a communi- 
cation which is contained in the Journal of the Royal Institution 
of Cornwall for 1866. There are no circular or oval cavities 
visible. 
The streaming operations in Stony Bottom, through which the 
Hook Lake flows, are considerable, and indicate great activity 
among the tinners in this neighbourhood. Close by are many 
groups of hut circles, in several cases surrounded by ruined walls 
forming enclosures or pounds. 
That which is known as Erme Pound is of considerable extent, 
and encloses a dozen hut circles. This pound is figured in the 
fifteenth century map of Dartmoor, which delineates the Perambu- 
lation of 1240, and was doubtless in use many centuries since for 
herding cattle. Outside, and between the pound and the Erme, 
are two ruins of rectangular buildings which may have been 
tinners' huts, or were used in connection with the pound. One ruin 
is curious, for it possesses a bench composed of flat stones, which 
run around both sides and one end, and having somewhat the 
shape of an horseshoe. 
About one and a half miles above Erme Pound are more 
extensive stream works, with coffins or open trenches and excava- 
tions, known as Erme Pits. The heaps of debris here are gigantic, 
and one pit is both large and deep. They were worked two 
hundred years since, for they are referred to in Metallographia ; 
or, An History of Metals, by John Webster, Practitioner in Physick 
and Chirurgery, published in London in 1672. The author in 
the chapter on tin refers to Dartmoor as follows : 
" Now I shall give the Eeader such informations as I received 
from one Thomas Creber of Plimpton S l Mary in Devonshire, who 
was one (and all his ancestors before him) that had wrought in 
the Tin-mines ; and these particulars I had of him. 
2 Since writing this paper the author lias investigated the ruins of two 
more blowing houses situated on the Walkham above Merivale Bridge. Both 
have very perfect mould stones, containing in addition to the mould a small 
cavity in each ; the latter are evidently intended for sample ingots. 
