PREVIOUS MAI'S. 



state. Subsequently, many of these points were redetermined by the 

 Coast and Geodetic Survey, by more elaborate methods, thus furnishing 

 what served substantially as a primary system of triangulation within which 

 and to which the Borden work has been adjusted. As thus adjusted, the 

 Bordeik locations are sufficiently accurate for the ordinary needs of map 

 work upon the scale of one mile to an inch. 



New York. — For several years, terminating in 1885, the state of New 

 York supported a survey which was devoted to the geodetic location of 

 points within its area. The work was of a high grade, comparing favora- 

 bly with that of the Coast and Geodetic and Lake Surveys. 



For many years also, the same state supported what was known as the 

 Adirondack Survey, which was engaged mainly in a triangulation of the 

 Adirondack region. Of this work few results have been published. 



New Jersey.— -In the year 1875, the state of New Jersey instituted a 

 topographic survey of its area. The plan of the work contemplated a map 

 upon a publication scale of one mile to an inch, with contours at vertical 

 intervals ranging from 5 to 20 feet, Control of the work was furnished in 

 part by the triangulation of the Coast and Geodetic Survey and in part by 

 triangulation of its own. In July, 1884, the completion of that state was 

 undertaken by the U. S. Geological Survey, by which organization it was 

 pushed forward to a conclusion in 1887. 



Pennsylvania.— -In Pennsylvania considerable topographic work has 

 been done by the State ( Geological Survey. This work is of a local char- 

 acter and confined to small areas, which have been mapped upon large 

 scales, and the aggregate area is not large. It was carried on by traverse 

 by the use of stadia and level. 



RAILROAD AND OTHER SURVEYS. 



Besides the material above enumerated, there exist in various parts oi 

 the country maps in great number and of varying quality. They consist of 

 town and county maps, mainly made by traversing roads with odometer 

 and compass, of railroad lines, executed in the ordinary manner by transit 

 and chain, the surveys of the boundaries of the states and territories, etc. 

 Some of this material may prove of service. 



