ON THE DETRITAL TIN-ORE OF CORNWALL. 249 
The entire County now yields only about fifty tons of Stream- 
’ tin-ore a year.* 
The Royalties (Dues) reserved by the owners of mineral 
rights, are, generally, higher in stream-works than in mines. In 
one instance—where the difficulty and risk are exceptionally 
great—the proprietors receive one-twentieth ; in most other cases, 
however, they are content with from one-fifteenth to one-twelfth, 
but in one district—perhaps the roughest and poorest in Cornwall 
—the Lord exacts one-tenth of the entire produce.+ 
Ancient furnaces—locally known as Jews’-houses—have, from 
time to time, been discovered in various parts of Cornwall; and 
rudely moulded blocks of metal—generally called Jews’-house-tin 
have been found still more frequently. Such furnaces and masses 
of metal have—it is scarcely requisite to say—no necessary 
relation to detrital deposits; but the smelting-works and their 
products are often—perhaps mostly—found in the neighbourhood 
of the stream-works ; and imperfectly smelted specimens of Jews’- 
house-tin,—sometimes obtained—consist of stream-ore mixed with 
charcoal and cemented by metallic-tin.; Neither furnaces nor 
blocks of Jews-house-tin, however, have been numerous on the 
coast or at great elevations. 
‘““At Morro Velho [in the same district] the ore which escaped 
“from the dressing-floors in suspension, was collected on the margin of a 
“neighbouring stream; where—by being again stamped and washed,—it 
“yielded from 1856 to 1863, one thousand three hundred and sixty five 
‘‘ (Troy) lbs. of gold.” Symons, Reports of the Saint John del Rey Company, 
“xxvii, p. 40; xxvili, p. 47; xxix, p. 43; xxx, p. 43; xxxi, p. 48; Xxxxii, p. 
60. Drerzscu, /bid, xxxiii, p. 50; xxxiv, p. 49. 
.  # Mr, Francis Michell of Calenick and Mr. Richard Wellington of 
Chyandour, MSS. 
+ ‘‘When a Streaming Tinner...takes a lease...he agrees to pay, the 
“ owner or lord of the fee, a certain part clear of al] expense...The consider- 
‘ation is generally one sixth, seventh, eighth, or ninth,...or instead thereof, 
‘‘he contracts to employ so many men and boys...and to pay the land-owner, 
‘for liberty, from twenty to thirty shillings a year for each man, and...for 
‘every boy...half as much as for a man.” Prycr, Mineralogia Cornubiensis, 
p. 132. 
t Ante, p. 226. Note. 
