86 National Geographic Magazine. 



method, and it might be inferred that the former work is better 

 controlled than the latter. I do not judge, however, that this is 

 the case, owing to the fact that traverse stations are not of as 

 much value for purposes of location as those by intersection. 

 The latter are selected points. The former are not selected 

 points, but on the contrary, a large proportion of them are 

 located simply for carrying forward the line and are of no further 

 service, and very few of them are such as would be fitted for the 

 purpose of controlling areas. 



Within the area surveyed by traverse nearly every mile of road 

 has been run. With the exception of those in the cities, nearly 

 every house and every church in the commonwealth has been 

 located, either by intersection with the plane table or by traverse. 



The organization of the surveying parties has been of the sim- 

 plest character. Plane table work has been carried on by one 

 man with an assistant, the latter doing little more than attend the 

 plane tabler and assist him in carrying the instruments. Each of 

 these little plane table parties was furnished with a horse and 

 buggy for transportation. The organization for traverse work has 

 been equally simple, consisting of a traverse man and a rodman. 

 As a horse and buggy would be an impediment in this work, this 

 feature of the outfit has been omitted. In the mixed work the 

 traverse men have been under the immediate control of the plane 

 tabler, so that their movements have been directed by him in de- 

 tail. The average output per working day of the plane tabler has 

 been for the whole survey 3,1 sq. miles, and of the traverse man 

 2.8 sq. miles, and, as the expenses of the former have been slightly 

 greater than those of the latter, the cost per square mile of the two 

 methods of work has been substantially the same. 



The average cost per square mile of the survey of the State has 

 been a trifle less than |13. This includes the salaries of all men 

 engaged upon the work during the field season, their traveling, 

 subsistence and all other expenses, the salaries of the men engaged 

 in di'awing the maps in the oflSce, the cost of supervision and of 

 disbursement, — in short all expenses of whatever character, in- 

 curred in the production of the map. 



