IV

general intelligence and scientific knowledge shouldplace their valuable convertible property in a cast-iron safe, with a box of wards for a lock, expectingthat it will preserve such contents from destructionby fire and abstraction by thieves. That others forthe sake of saving a few shillings in the primarycost of a lock for the safe keeping of their propertyin an iron safe or other receptacle, will purchaseone that can be readily picked with a quill or askewer, not only by the accomplished burglar, butby any ordinary mechanic or intelligent artisan, aswell as by the amateur lock-picker.

As there are no works in our language, excepta few pamphlets and a rudimentary treatise, on thesubject of locks, I have added the chapters on locksand keys , in order to make this treatise as completeand useful as possible.

I am especially indebted for many extracts toMr. Granville Sharp ’s “ Prize Essay on PracticalBanking ,” Mr. Chubb’s paper “ On the Constructionof Locks and Keys,” and the “ Rudimentary Treatiseon the Construction of Locks,” by Messrs. Tomlinsonand Hobbs,—works of such an interesting characterthat they should be read by all. Other generalworks have afforded me considerable information.