ORDNANCE SURVEY 
OF 
THE COUNTY OF LONDONDERRY 
LIEUTENANT COLONEL COLBY, 
OF THE ROYAL ENGINEERS, 
F.R.S. L. AND E., M.R.I.A., ETC. ETC., 
SUPERINTENDENT. 
DUBLIN: 
PUBLISHED FOR HIS MAJESTY’S GOVERNMENT, 
BY HODGES AND SMITH, 21, COLLEGE-GREEN. 
M.DCCC.XXXV. 
