y not unknown to the Romans. But the grouting machine is a
modern invention, and it has only been applied to ancient buildings
during the last six or seven years.[65] It is unnecessary to describe
its mechanism, but its admirable results may be summarized. Suppose an
old building shows alarming cracks. By compressed air you blow out the
old decayed mortar, and then damping the masonry by the injection of
water, you insert the nozzle of the machine and force the grout into
the cracks and cavities, and soon the whole mass of decayed masonry is
cemented together and is as sound as ever it was. This method has been
successfully applied to Winchester Cathedral, the old walls of
Chester, and to various churches and towers. It in no way destroys the
characteristics and features of the building, the weatherworn surfaces
of the old stones, their cracks and deformations, and even the moss
and lichen which time has planted on them need not be disturbed.
Pointing is of no avail to preserve a building, as it only enters an
inch or two in depth. Underpinning is dangerous if the building be
badly cracked, and may cause collapse. But if you shore the structure
with timber, and then weld its stones together by applying the
grouting machine, you turn the whole mass of masonry into a monolith,
and can then strengthen the foundations in any way that may be found
necessary. The following story of the saving of an old church, as told
by Mr. Fox, proclaims the merits of this scientific invention better
than any description can possibly do:--

"The ancient church of Corhampton, near Bishops Waltham, in
Hampshire, is an instance. This Saxon church, 1300 years old, was
in a sadly dilapidated condition. In the west gable there were
large cracks, one from the ridge to the ground, another nearer the
side wall, both wide enough for a man's arm to enter; whilst at
the north-west angle the Saxon work threatened to fall bodily off.
The mortar of the walls had perished through age, and the ivy had
penetrated into the interior of the church in every direction. It
would have been unsafe to attempt any examination of the
foundations for fear of bringing down the whole fabric;
consequently the grouting machine was applied all over the
building. The grout escaped at every point, and it occupied the
attention of the masons both inside and outside to stop it
promptly by plastering clay on to the openings from which it was
running