A dissertation on the construction of locks : containing, first, reasons and observations, demonstrating all locks, which depend on fixed wards, to be erroneous in principle, and defective in point of security : secondly, a specification of a lock, constructed on a new and infallible principle, which, possessing all the properties essential to security, will prevent the most ruinous consequences of house robberies, and be a certain protection against thieves of all descriptions /