It soon became the habit of the printers to open shops apart from their printing offices for the sale of their productions. These salesrooms developed into book-shops through carrying in stock the books of other printers. In the old-world cities trades had a habit of congregating in one place. If a man wanted to open a book-shop, instead of trying to find a good location where there were no other book-shops very near at hand, he tried to get a location as near as he could to all the other book-shops. In this way certain streets or quarters of the cities, and particularly of London, were given up to certain industries. The centre of the English book trade of the seventeenth century was the churchyard of the old St. Paul’s Church. This was the smaller church which occupied the site where now stands the magnificent St. Paul’s Cathedral built by the great architect Sir Christopher Wren after the fire of 1660. A glimpse of the way in which the business was done may be obtained from the following description of John Day’s book-shop: “He got framed a neat handsome shop. It was but little and low, a flat roof, and leaded [covered with sheets of lead] like a terrace, railed and posted, fit for men to stand upon in any triumph or show.” Evidently thrifty John Day was not above turning an honest penny by renting the roof of his shop to those who desired to see the Lord Mayor’s show or some other glittering procession. All processions of any importance passed St. Paul’s. We are told that this shop cost £40 or £50, which would be equivalent, making allowance for the difference in the purchasing power of money, to from $1200 to $1600 to-day. We are told that £150,000 worth of books were burned at St. Paul’s churchyard and in the crypt of the church in the fire of 1666. This represents no less than $4,000,000 in our present money.