This padlock was therefore a hand-drawn, and not a key-drawn, lock. Its origin is at present uncertain, but it is here no doubt represented in its more complete and developed state, after having already undergone prior modifications. The absence of simpler contrivances of the same kind suggests the inference that its forerunners may have been made of perishable materials. Be that as it may, its progress onward from this point of perfection can be traced with some degree of certainty. Already in Roman times it had undergone changes. Amongst the Roman antiquities discovered in 1854 by the Honourable RICHARD NEVILLE (since Lord BRAYBROOKE), at Great Chesterford, in Essex,[27] were two kinds of this padlock: one, represented in fig. 23C, Plate V., is of the form already described; the other (figs. 24C and 25C, Plate V.) was constructed on what, judging by those which succeeded it, must probably have been regarded as an improved form, or it may have been merely adapted to a different purpose. The bolt _a_, instead of having perpendicular bars and rings to slip over the parallel bar, was simply a plain straight bolt with the catch springs attached to it. The horizontal parallel bar of the lock, after passing along the top of the box or tube, was curved down over the mouth of the lock, at a short distance from it, and terminated in a ring, leaving a space between it and the mouth of the tube to admit of the passage of the chain or staple, or whatever was intended to be secured by means of the padlock, as shown in fig. 25C, Plate V. The bolt was slipped through this ring, and on into the tube, the barbed springs flying out and catching after they entered the box, so as to fill up this space and secure the bolt, which was opened and withdrawn in the same manner as before, as shown in fig. 24C, Plate V. [27] 'Archæological Journal,' vol. xiii., p. 7, Plate II., figs. 24 to 27.