First, the broker must know who would sell. To do that he must know who owns the property. To gather this from the Hall of Records is an insuperable task; unless one name in the chain of title is known, it is practically impossible. Previous to 1892, the index to conveyances was kept in alphabetical order, and to locate a given property thousands of deeds might have to be read. Since 1892 only those in any given block would have to be followed up. But that in itself is a huge task. This work has all been simplified by the compilation called the Real Estate Directory of Manhattan.

This directory is cross-indexed. The first is geographical, according to street number. This division gives the street number, the block and lot number, the last owner of record at the date of publication, the date of record, and in the case of multifamily houses, a full description, such as flats to the floor, rooms to the flat, steam heat, hot water, elevators, store fronts and the like. The second classification is alphabetical. In this part each property owner's name is arranged in alphabetical order, followed by his address and a list of his holdings. So, to locate the owner of a particular parcel, turn first to the street, glance down the column to the number, and then turn to the name given in the alphabetical section for the address. But ten to thirty thousand parcels change hands each year. How can it be known that this very parcel has not been transferred? A weekly supplement is issued giving the property sold or bequeathed and the name and address of the purchaser or heir. To avoid a search for the owner through a number of these supplements, a cumulative index called the Checking Index is issued each week. Thus the first index of the year contains the first and second week, the second, the first, second and third week, and the fifty-first the last one of the year, the whole fifty-two weeks inclusive. After that a new real estate directory is issued. Thus one great labor existing in the past has been eliminated by a central co-operative bureau.

A more comprehensive and more expensive system is one which does away with the weekly supplement and Checking Index, and reports each conveyance as it is recorded on a separate filing card. This card bears an abstract of the title. As property is transferred not only by conveyance but by will and letters of administration, the means of transfer is specified.