Some people expect perfect impossibilities, and imagine that, having obtained a secure lock, they have done all that is necessary. No lock whatever will guard against culpable negligence with regard to its key; or, as in the famous South-Eastern Railway bullion robbery, the treachery of supposed trustworthy servants. It will be remembered that the notorious lock-picker Agar said the robbery on this railway would be impossible unless copies of the keys could be taken. By the connivance of a guard named Tester this was accomplished, and yet the duplicate keys thus made were useless until Agar had travelled seven or eight times to Folkestone with the chests, altering the keys until they fitted.
Since 1851 many improvements have been made and adopted in Chubb’s locks, and more still have been tried and rejected, as interfering with their proper working. Complexity of action in any lock will sooner or later invariably prove fatal to its success. A lock is unlike a
watch or other delicate machine that is treated with a considerable amount of carefulness; it is subject to every day hard wear and usage. Absolute perfection is perhaps as unattainable in locks as in other matters; nevertheless the present is an age of progress, and a more perfect lock may perhaps be invented some day. Lock patents by scores have appeared within the last twenty-one years; some good, others indifferent or bad in principle, and many of them embracing as new ideas certain principles of construction long since exploded or laid aside. Of those practically defunct (and they are many), my opinion of them is that the ingenuity of the inventors has generally been allowed to over-run their perception of the before-mentioned fact, viz., that a lock is a very hardworked machine, and that in its construction simplicity is as necessary an element as security.
A good lock cannot have a key made to it unless another key is available to copy from or the lock itself can be broken open. Of this latter fact London burglars have not been slow to avail themselves, and they have tried it in the following manner. It should first be said, for those not acquainted with the mode of securing warehouse and office doors at night, where the buildings are left unoccupied, that such doors are usually fastened with a large rim or mortise lock of the ordinary kind. When this is locked from the outside a small flat bar, that is secured at one end to the door, is put across the keyhole to a staple thereon, fastened by a padlock. The advantage of this plan is that the inner lock cannot be touched, the keyhole being closed while the outer lock is secure; and this padlock being visible, the police in their rounds can tell by a glance under the light of the bull’s-eye whether or not it has been interfered with. But there is such a thing as forcing a padlock completely open, with proper appliances; and some clever burglar watching the policeman off his round past a warehouse in Watling Street, one night, wrenched the padlock off and supplied its place by a common one, the outside of which in the dark resembled the one previously on. He then took the patent lock away, got one side off, cut out all the works, so that anything like a key would at once open or close the bolt, fastened the side on as neatly as was possible, took it back to Watling Street again, and watching his opportunity took his own lock off and refixed the empty shell of the patent lock. The purpose in all this was that next night he might at once open the padlock, force the inner lock, and enter the place, while a confederate would doubtless