They had furthermore absorbed the knowledge that in several parts of London town were large fabricks called Gates, viz. Ludgate, Moorgate, and Bishopsgate. They had even passed through Aldgate a few times, that being their usual way of invading the city. But the connexion between gates of that type, and hog-yard-wickets, was most obscure. A gate in the hog-yard sense of the word made no sense unless built in a wall, fence, or other such formal barrier, as its purpose was to provide a means of passage through same. But none of the large London buildings called Gates appeared to have been constructed in any such context. They bestrode important roads leading into the city, but if you didn't want to pass through the actual gate, you could usually find a way round.