158 EARL DE GREY'S ADDRESS. [May 28, 1860. 



two distinct branches, viz., tlio Ordnance Survey of the United 

 .Kingdom, and the Topographical and Statistical Depot of the War 

 Office : previously to the year 1857 they were superintended by 

 officers who were quite independent of each other, but since then 

 they have been formed into one Topographical Department, and 

 placed under Colonel Sir Henry James as Director. 



Ordnance Survey. — -A Eeport of the progress of the department 

 during the year 1859 has been laid before Parliament, and from 

 this Eeport we are able to state the exact progress which has been 

 made in the Ordnance Survey up to the present time. And first, 

 as regards the great trigonometrical operations of the survey, we 

 learn that the principal triangulation and the principal lines of 

 levelling in Ireland have been already published, and that the 

 principal lines of levelling in Great Britain are in the press, and 

 will be published this year, and complete this great branch of the 

 work which commenced so long ago as the year 1784 under 

 General Eoy. 



Along these principal lines, which are laid out as a network 

 over the whole country, broad arrows, or the Queen's marks as they 

 are sometimes called, have been cut upon the churches, bridges, 

 and other permanent structures, as the exact points to be found 

 on the ground to which the levels refer ; and as the heights of 

 these points are all given in reference to the level of mean-tide 

 at Liverpool, they form accurate definite points of reference for 

 those who are engaged in any great engineering operations, such 

 as the laying out of railways, roads, canals, or the drainage of 

 extensive districts, as well as points of reference for connecting 

 the levelling taken within these lines in the execution of the 

 Ordnance Survey. 



It will be remembered by all who have taken any interest in the 

 progress of the Ordnance Survey, that after the 1-inch map of 

 England and Wales had advanced from the Land's-end to the 

 borders of Yorkshire and Lancashire, the survey of Great Britain 

 was suspended, that the survey of Ireland might be taken up on 

 the scalb of 6 inches to the mile ; and that after all the plans of 

 Ireland had been published on the 6-inch scale, the surveys of 

 England and Scotland were resumed. After much discussion on 

 the subject, and the appointment of a Eoyal Commission under 

 Lord Wrottesley, it was definitely settled that the scale for the 

 large plans of the cultivated districts should be the gVooj or 25*344 

 inches to a mile ; that the scale for the large uncultivated district 



