Page:A Dissertation on the Construction of Locks (1785).pdf/21

 impediments, may render the paſſage to the bolt ſo intricate and perplexed, as to exclude every inſtrument but its proper key; a ſkilful workman having acceſs to the entrance, will be at no loſs to fabricate a key which ſhall tally as perfectly with the wards, as if the Lock had been open to his inſpection. And this operation may not only be performed to the higheſt degree of certainty and exactneſs, but is conducted likewiſe with the utmoſt eaſe. For the block or bit, which is intended to receive the impreſſion of the wards, being fitted to the key-hole, and the ſhank of the key bored to a ſufficient depth to receive the pipe, nothing remains but to colour the bit with a preparation, which, by a gentle preſſure againſt the introductory ward, may receive its impreſſion, and thus furniſh a certain direction for the application of the file. The block or bit being thus prepared with a tally to the firſt ward, gains admiſſion to the ſecond, and a repetition of the