Arthur Brunel Chatwood

“ This patent is noteworthy as being the only one connected with the lock and safe industry which has been extended by the privy council.
It is about this period (1860–1870) , perhaps the most important in the history of safes, that the opening of safes by wedges seems to have become prominent. The effect of wedges was to bend out the side of the safe sufficiently to allow of the insertion of a crowbar between the body and the edge of the door, and various devices were adopted by different makers with the object of resisting this mode of attack. ”

“ The earliest examples extant were constructed of hard wood banded with hammered iron, and subsequent development took place rather on artistic than on practical lines up to the time of the introduction of boxes entirely of iron. On the continent of Europe the iron box was developed to a very high standard of artistic beauty and craftsmanship, but with no real increase of security. ”

“ For many years little advance was made except such as consisted in substituting steel for iron and in general gaining increased strength by the utilization of better materials, although many safes are made and sold to-day which -offer little if any more resistance to Ere and thieves than those of 1860–1870. About 1888 the “solid” safe was introduced. In this the top, bottom and two sides of the safe, together with the flanges at the back only or at both back and front, are bent from a single steel plate (fig. 3) . This construction, with solid corners, also illustrated in figs. ”

“ The space between the outer body and the inner casing must be properly charged with a steam-generating mixture in sufficient quantity to keep the interior of the safe moist for the whole time during which it may be subjected to heat in the case of a fire. ”

“ The use of high explosives has become a more frequent method of attack by burglars in Great Britain, but where the safes have been of the best quality, of solid construction and good workmanship, this means of attack has been rendered ineffective. ”

“ Where the value known to be contained in a strong-room is sufficiently great, an attack by tunnelling must be specially guarded against, and as in this form of attack the time which may be devoted to preparing for the actual breaking through is practically unlimited, the use of some device which will give warning of any such attack before the floor of the strong-room itself is reached is of very great importance. Probably the best of such devices, and one which is in practical use, consists of a network of small pipes, laid in concrete below the floor, and filled with glycerin or other liquid. ”

“ The timber construction employed in American buildings rendered fires much more fierce, but at the same time of very short duration, not more than an hour or two, To meet this condition of affairs thick, sides of non-conducting materials were more efficacious than the, chambers of steam-generating, materials employed in British construction, but the gradual abandonment of timber and the increasing size of buildings have called for changes in the methods of fire-proofing. ”

“ If any breach is made in the pipe system, a leakage takes place, causing an alteration in the level of the mercury in the manometer, which may, if desired, be arranged to ring a bell. The manometer should in any case be observed regularly on the opening of the strong-room. ”

“ It is fitted with a ground-in door rotating concentrically with the shell and internally. The spherical form and great thickness render the useful space in the interior very small and of inconvenient shape. ”

“ Railway metals attached to steel plates and also bedded in concrete are very largely employed. Thick plates of steel and latterly of manganese and other special, steels are also in common use. Various forms of strong-room walls are illustrated in fig. ”