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.

“After the operation had been completed and the clay was removed, the interior was found to be completely filled with cement set very hard; and sufficient depth having been left for fixing the flint work outside and tiling inside, the result was that no trace of the crack was visible, and the walls were stronger and better than they had ever been before.  Subsequent steps were then taken to examine and, where necessary, to underpin the walls, and the church is saved, as the vicar, the Rev. H. Churton, said, ’all without moving one of the Saxon “long and short” stones.’”

  [65] A full account of this useful invention was given in the
  Times Engineering Supplement, March 18th, 1908, by Mr. Francis
  Fox, M. Inst.  C.E.