Another form of internal analysis is the bank audit, which differs from an examination, especially in pur-pose. It has been shown that the examination of a bank seeks to verify the existence and value of assets and liabilities at a fixed date as compared with the corresponding entries in the bank's ledgers. The audit proceeds a step farther in checking the records themselves. Besides, an audit is made not alone to determine the accuracy of the accounts, but also to test the efficiency of the methods used in keeping these records. Audits should result in the installation of systems which possess a minimum of error and a maximum of economy. The records of the bank may be audited by a firm of public accountants employed by the board of directors. Audits may also be made by members of the bank's staff. In a small bank this task quite naturally devolves upon the cashier, but another way is to rotate the clerks from one department to another so that they will verify records which they do not handle in the course of their daily work. A large bank maintains an auditing department, in order that the more important transactions can be placed under constant observation. According to the frequency with which audits are made, they may be classed as either periodic or continuous. The former are made only at various intervals throughout the year, especially in the case of a small bank, while a continuous audit is essential in departments of a large bank handling the shipment of cash and securities.