488 Goal Washing. [Oct., 



mode of making iron in Sontli "Wales about the year 1750, in which 

 it is stated as follows : — " On the wash, or enclosed ground on the 

 sides of the hills, where we find oar, we dig a trench about 4 or 

 5 foot wide, till we come do^vn to the lowest vein, about 14 foot 

 deep, and in that depth is usually four veins or layers of oar. 

 Then we make small ponds to hold rain water, or any that comes 

 out of springs, above the trench that is cut ; and as fast as the ponds 

 fill, we let them down by a flood-gate into the trench, which carries 

 away all the loose earth, and leaves the myne behind, and the 

 lowest vein bare. They then undermine the banks of the trench 

 on both sides, and when great quantities of the banks are fallen 

 down, they let down the water out of the ponds again, which 

 washes away all the earth from the myne." Such then was the 

 rude method of washing u-on ore 120 years ago ; but although so 

 primitive in method, the principle, it will be recognized, was the 

 same as that which prevails in ore-washing machines of the most 

 approved type at the present day, the separation of the ore from the 

 earthy matters being due to gi-avitation. Thus whilst the hghter 

 particles were carried away by the water, the heavier and mineral 

 portions were left behind. 



Although coal washing has now been practised all over the Con- 

 tinent for about half-a-century, until comparatively quite recently 

 the practice of washing the products of coal mines was unknown in 

 this country, and for the following reasons. Coal, unlike almost 

 every other mineral product, is found running in broad seams, 

 varying from a few inches to many feet in thickness ; and so gi'eat 

 is the quantity in which it exists that the richer seams only are 

 considered worth working at all, and from these blocks are obtained, 

 possessing a very high degree of purity. Not many years back, it 

 was the custom to leave all the small coal down at the bottom of 

 the pit, or, if it was brought to the sm-flice, it was either burned at 

 the pit's month as so much worthless refuse, or run to spoil. Indeed 

 so wasteful has been the manner in which coal-mining operations 

 have been carried on, that large quantities of valuable fuel have 

 been lost, or habitually h'ft at the bottom of the pit as not being 

 worth raising to the surfiice. This subject was closely investigated 

 in 1860, by Mr. Alexander Bassett, of Cardil!',* the result of whose 

 inquiries showed that from thirty to forty per cent, of the products 

 of mines is not imfrequently lost, owing to the imperfect method of 

 coal " getting " usually adopted ; but that where, either from the 

 character of the seam of coal, or from the mode adopted in working, 

 a less percentage of fuel is lost, " still, under the most improved 

 system, the quantity of small coal left in the mines, and conse- 



* " On tlic Largo Proportion of Coal lost in Worlviiiu;." Paper road Ixfore tlie 

 Boutli Wales Iu>stitutc of Engiiietrs, in February, I8(J1, \>y Mr. Aluxauikr Bassttt, 

 M.I.C.E. 



