How to estubUsli a Tile- Yard. 
465 
rollersj or in a round stone trough with a revolving stone wheel ; 
it is then passed through a hopper into pug-mills, and is there 
mixed with water until it becomes of a proper consistency for 
moulding tiles. 
I will next mention, under one head, all clays that are improved 
by washing. Under this head may be enumerated those con- 
taining chalk, sand, or stones ; those of a very tenacious character, 
containing limewash (which require lowering), and many others. 
These are found principally in the eastern parts of Norfolk, in 
Suffolk, Essex, parts of Huntingdonshire, Lincolnshire, parts of 
Berkshire, parts of VV^iltshire, the Vale of Aylesbury, and in so 
many other places that it is very important its management 
should be clearly understood. The best tiles I have ever seen 
have been made from these clays — they are generally light- 
coloured, very hard, burn quite straight, and are very sound. 
Where these clavs are found, I recommend to commence digging 
and washing in November, leaving it in pits, arranged for the 
purpose, until the beginning of April in the following year. It 
is then ready for the pug-mill, which is necessary for its perfect 
amalgamation: for if the pug-mill were not used, it would not 
be projierly mixed and of one consistency, which is absolutely in- 
dispensable for making tiles bv machinery: little or no waste is 
found in the manufacture, and I am convinced that all clays of 
sufficient tenacity, that can be conveniently washed, will produce 
an article better in quality and at a less cost. 
Before treating on the subject of washing, I may remark that 
allowance must in all cases be made for climate, and the humidity 
of the atmosphere. For instance, when clay is washed in North- 
umberland and in Hampshire, many months more must be allowed 
in the former than in the latter for it to become sufficiently con- 
solidated prior to use — the force of the sun, in the early spring 
months, being much less in the one than in the other. The 
subject of washing clay is one which has hitherto been little 
understood, but its great importance is daily becoming more ob- 
vious to those connected with tile-making:. In the neighbourhood 
of London it has been practised many years, but more for the 
purpose of admixture with chalk for brick-making than for 
cleansing clay from its various impurities for tile-making. In 
many parts of England, especially in some of the counties last 
alluded to, it would be impossible to make tiles without it. It 
has been argued and set forth by many that washing clay is an 
expensive and difficult operation. Few things are otherwise, until 
they are well understood; and I can prove that for tile-making it 
not only tends to facilitate the working of the various machines, 
but actually reduces the cost of manufacture. To illustrate this, 
