It should be a great object with the chief clerk to see that the customers' books are written up correctly and neatly, in a good handwriting, and free from blots or erasures. These are the only books that go out of the bank, and therefore they are the chief means by which the customers can judge as to the manner in which the business of the office is conducted. It is not advisable that the writing up of these books should be left to the junior clerks. They should be placed in the hands of clerks of some standing. The same book should always be written up by the same clerk; and when it can be so managed, the credit and debit side should both be in the same handwriting. One of the best writers in the office should be appointed to this post, and his salary should be proportionate to its importance.

It is the practice of all bankers to let the customers' book be a copy of the ledger with the sides reversed, Thus the credit side of the ledger is the debit side of the customers' book. The reason assigned for this is, that the ledger is the banker's account against his customer, and the book is the customer's account against the banker. Hence the customer, when he looks at his book, has at his left hand the sums with which he has debited his banker, and at his right the sums which are to the banker's credit.