412 



ANNUAL OF SCIENTIFIC DISCOVERY. 



The foregoing positions are all derived from astronomical observations, 

 carefully made, with good instruments. 



The following additional positions are given as approximations, near 

 enough for general geographical purposes, such as the projection of maps, 

 etc. 



They are derived from measurements of courses and distances, made 

 on C. H. Stoddard's map of Scott County, Iowa, and Rock Island County, 

 Illinois, published in 18-37, from our astronomical station in the centre of 

 Washington Square, in the "City of Rock Island," Illinois. See No. 10 in 

 the Table. 



The said map is, we believe, compiled from the United States public land 

 surveys. 



