mething
not to be described. There were vaults under some of the warehouses
stored with inflammable materials, the contents of which caught fire and
burnt for a fortnight, defying all attempts to put them out. Yet these
very vaults, though they were blazing furnaces for all that time, were
not materially injured. When the warehouses came to be reinstated, it
was only found necessary to repair and repoint them a little, and they
were retained in use. The fact is that the bricks have been calcined
already, so has the lime in the mortar, and the sand is not affected by
heat, so there is nothing in brickwork to burn. Against each of these
good qualities, however, we may set a corresponding defect.

If brickwork is easily thrown into any shape, it is also easily thrown
out of shape. It has little coherence or stability, less than masonry
and very considerably less than timber. If any unequal settlement in the
foundation of a brick building occurs, those long zigzag cracks with
which we in London are only too familiar set themselves up at once; and
if any undue load, or any variation in load, exists, the brickwork
begins to bulge. Any serious shock may cause a building of ordinary
brickwork to collapse altogether, and from time to time a formidable
accident occurs owing to this cause. The fact is, the bricks are each so
small compared to the mass of the work, and the tenacity or hold upon
them of even fairly good lime mortar is so comparatively slight, that
there is really but little grip of one put upon another.

Persons who have to design and construct brick buildings should never
forget that they have to be handled with caution, and are really very
ticklish and unstable. One or two of the methods of overcoming this to
some extent may be mentioned. The first is the introduction of what is
called bond. At the end of the last century it was usual to build in, at
every few feet in height, bond timbers, which were embedded in the heart
of the walls. If these had always remained indestructible, they would no
doubt have served their purpose to some extent. Unfortunately, timber
both rots and burns, and this bond timber has brought down many a wall
owing to its being destroyed by fire, and has in other cases decayed
away, and caused cracks, settlements, and failures.

The more modern method of introducing a strong horizontal tie is to
build into the wall a group of bands of thin iron, such as some sorts of
barrels are hooped wit