19. Ledger systems.—The use of special forms of ledgers is closely related to this subject. In a small business it may be that all the bookkeeping can be performed by one person, and all the accounts can be kept in one book. The more complex system has been discussed, and it has been explained how the ledger, under that system, is separated into the general ledger and the subsidiary ledger containing the indi vidual accounts, which are branches of the various con trolling accounts. The general ledger derives its name from the fact that it contains complete data con cerning the condition and the operations of the entire business, tho in a summary form.
In contrast, the customers' and the creditors' led gers, and other subsidiary ledgers, are often referred to as detailed ledgers, because they contain detailed information about a class of accounts. The idea of the detailed ledger, with its controlling account, may be adopted very extensively. In the case of a large business corporation, nearly every account in its gen eral ledger may be a controlling account. The land
account may control a land ledger, in which an ac count will be kept with each tract of land owned. The buildings account may control a building ledger, which will contain an account with each building. The machinery account may control a machinery ledger which will include an account with each class of machines, or perhaps even with each individual ma chine.
In the case of many railroad companies, the equip ment account may control an equipment register, in which there will be a record of each of the hundreds of locomotives and the thousands, or tens of thousands, of freight and passenger cars, showing for each its date of acquisition, cost, wearing-out or depreciation, rate, cost of repairs and the like. This illustration should help us to understand that account names are but class names, and that the class lines may be broadly or narrowly drawn, according to the particular business.