In some cities and in nearly all country towns real estate assessment rolls are still arranged alphabetically instead of geographically, and in most country towns the assessment of the real estate of residents depends for its validity upon the correct designation of the owner. This system unnecessarily injects the personal element, occasionally invalidates the assessment, and worst of all, renders comparison of assessed values exceedingly difficult. Moreover, the alphabetical arrangement depending upon the correct designation of the names of owners requires a separate roll or a different method for the assessment of the property of residents and non-residents. Altogether, the alphabetical system has nothing to commend it, unless it be a necessity caused by the absence of proper maps.

Accurate maps are the foundation of a good system of assessing real estate. The maps should be prepared in accordance with the block system, similar to that in the City of New York. This system is applicable to both city and country. An example of its use in country districts and cities as well may be found in the Cadastral System in the Province of Quebec. The entire province is divided into cadastres, the boundaries of which are unchangeable. Within each cadastre the lot numbers are changed as necessity requires. The system in the City of New York was first established to provide properly for the recording and indexing of instruments affecting land, by Chapter 166 of the Laws of 1890. This system was established for the assessment of real estate by Chapter 542 of the Laws of 1892.

Briefly described, the block system of assessment in the City of New York is as follows: A land map of the city was prepared under the direction of the commissioners of taxes and assessments, upon which was exhibited in sections and section numbers, and block and block numbers the separate lots or parcels of land taxed within each of the city blocks. Each lot or parcel of land shown on the map is designated by a lot number. The lot numbers commence in each block with Number 1 and continue numerically upwards for as many lots as are comprised within each block. The word "block" as used in this system designates a plot or parcel of land wholly embraced within continuous lines of streets or streets and water front, and may be more than a city square, but generally does not exceed 200,000 square feet in area. Blocks are numbered from number one consecutively upward. The numbers never change and the boundaries never change. The city is further divided into sections the boundaries of which are unchanging, and which are numbered consecutively from one up; each section is about three or four square miles in area.

On the assessment rolls the blocks appear consecutively and within each block the lots are placed in accordance with their location on the streets, commencing at one corner and proceeding continuously along each side of the squares which constitute the block. Any lot may be located rapidly and certainly, either on the assessment roll or on the map. For the convenience of the assessors, the maps are bound in volumes of suitable size with a key map in the front; the scale of the key map being from 300 to 700 feet to the inch and the scale of the official map being 50 feet to the inch.

The block system has not yet been extended to cover the entire City of New York, but it is being extended as rapidly as the work can be done and the street system becomes sufficiently permanent to establish unchangeable block lines. In the territory not yet covered by the block system the maps are temporary and are called tentative maps. As these maps cover territory held in large parcels, much of it farm land, the scale somewhat varies, being from 80 to 200 feet to the inch. So far as practicable, however, the same system applies in the territory only tentatively mapped. Every lot is numbered, and its position is designated by a number on the map and by ward, plot and map numbers. The length of all boundary lines is shown on the maps in feet and inches, and on valuable lots of irregular shape the area is shown in square feet; on larger parcels the area is shown in lots or acres.