246 



under the direction of Buraeus, and particularly encouraged 

 by Adolphus. In 1681, the Swedes had completed the ge- 

 neral topographical map of Sweden ; but it was kept secret, 

 and at the end of a century, they had only published some 

 parts of it. These maps were constructed for the purpose 

 of ameliorating the condition of several provinces of the 

 kingdom, which had been desolated by war. The Dutch 

 also commenced early to construct topographical maps. 



The measurement of many arcs of the meridian to deter- 

 mine the figure of the earth, had very much extended geo- 

 detical operations, and had, in many cases, become the 

 elements on which topographical maps were based. The 

 numerous geodetical surveys called into activity the inven- 

 tive powers of the ablest artists in Europe, and instruments 

 of extreme accuracy were produced ; and the skill of ob- 

 serving and determining angles kept pace with those im- 

 provements connected with this important branch of science. 

 The repeating principle due to the celebrated Tobias 

 Meyer, gave birth to Borda's circle of repetition about 1789, 

 an instrument which has been connected with the most bril- 

 liant scientific operations which adorn the annals of the 

 eighteenth century. 



Mr. Bald then showed to the Academy some specimens 

 of the new map of France, and noticed briefly the trigono- 

 metrical survey of England — the Down survey of Ireland — 

 the maritime surveys of Ireland — the county surveys, and 

 the bog surveys. He made some observations on the great 

 importance of accurate maps, especially to professional men 

 engaged in conducting public works, such as roads, canals, 

 river navigations, harbours, railways, supplying towns with 

 water, irrigations ; to the geologist and miner, exploring 

 the strata, and mineral wealth of the country ; to the states- 

 man devising improvements, and developing its resources ; 

 and to the poor, by affording useful employment to the 

 working classes. 



