246 THE ESSEX NATURALIST
more modern, brick pressing processes I will not now deal as they
are in essence similar to moulding by hand on a "stock".
I said just now that one feature characteristic of many bricks is
necessarily excluded in "wire-cut" bricks; I was referring to the
"frog", the recess in one face of a brick, intended to hold mortar
to reinforce the bonding between one course and another.
The series of bricks shows a progressive development of the frog
from a mere depression to a sharp-cut v-shaped slot in a modern
twentieth-century brick. But I must here utter a warning against
the common fallacy (not confined to this example) of supposing
that because a series of forms from simple to complex can be
selected to appear in order of date, this necessarily implies an
evolution. I have a brick of 1850 in which the frog has almost
exactly the shape of its late seventeenth-century predecessor.
It is necessary constantly to bear in mind that here is one of the
simple, fundamental industries in which, until quite recently, the
most primitive methods held sway. It must be expected that
reversion to earlier forms will often occur by re-invention, because
there are few if any subtle inventions in brickmaking; it has been a
simple craft, almost unchanged for millennia.
The Roman brick is included in my series to show the edge-
thickening which may have served, either deliberately or acciden-
tally, the same purpose as the later frog, which was formed, of
course, by suitably shaping the stock of the moulding-board.
In drying the bricks, sometimes a strong wind would cause the
outside to dry more quickly than the inside face, and the whole
brick became bowed, contracting most where it was first dry.
Such bricks, though now rejected, were prized in early Tudor days
for building well-shafts, round chimneys, and other structures
where their shape served the purpose. Later, such curved bricks
were made deliberately, as were the Roman segmental bricks to
which I referred previously.
The two thin bricks lying immediately above the Roman brick
(Fig. 17) are from Little Coggeshall Abbey buildings; they are not
whole bricks, I am sorry to say, but together are equal in length to
a complete brick of the period. The one piece is from the earliest
part of the structure built at the end of the twelfth century, the
other from the Dorter, probably about 1220, but there is no con-
siderable difference between them. They are very irregular in size
and rough in texture, but of a fine dark red-brown colour. The size
is, as an average, llin.-12in. long by 6in.-7in. wide and about
13/4in. thick. This medieval brick is very rare in Essex and else-
where; it is quite different from all later bricks, even of those made
so soon afterwards as 1260, which will be dealt with in a moment.
It is tempting to say that there is much in common between the
Roman bricks, particularly the thinner ones, and these earliest