124 eeport — 1877. 



of the work, remained to be surveyed ; this base was laid down in 1849 ; the 

 primary base-line, on the margin of Lough Foyle, was measured in 1827. The base 

 on Salisbury Plain was 360 miles away, aud its length in the first instance was 

 computed by a connected series of triangles projected on from Lough Foyle. When 

 this base was measured by the standard compensation base, it was found that the 

 actual measurement agreed within five inches of the length computed by the 

 triaugulation and trigonometry : this fairly expresses the accuracy which had now 

 been introduced into this branch of surveying. 



The English triaugulation was connected with the systems of France and 

 Belgium in 1862, and in 1865 a remarkable International Congress was held at 

 Southampton, in which town the standards of linear measure of England, India, 

 Russia, Belgium, Prussia, Austria, Spain, Italy, and the United States were com- 

 pared with each other as a preliminary to a measurement of a great arc of a 

 parallel of latitude. In the very year in which the British Association last met at 

 Plymouth, the arc of India, which extends from Cape Comorin to the Himalaya, was 

 completed. In 1867 a base-line was measured at Bangalore, which was found to 

 be within a quarter of an inch of the length that had been assigned to it by a 

 series of triangles from Vizagapatam. The detailed plan of the survey of London 

 was completed on 326 sheets in 1871. General Dufour brought out his celebrated 

 map of Switzerland in 25 sheets : this is one of the finest specimens of mapping the 

 physical features of a country ever accomplished. 



In the work of hydrographical progress we have ample reason to be proud of 

 all that has been accomplished by this country, under the direction of those 

 eminent hydrographers of the Admiralty — Beaufort, Richards, and Evans. To enu- 

 merate all the work that has been carried out by the several scientific naval 

 officers employed in the surveying service all over the world, and give them a full 

 consideration of their merits, is beyond the limits of this brief space ; the accuracy 

 of our surveys is so thoroughly credited, that our Admiralty charts and sailing 

 directions afford to the mariners of this great maritime nation every confidence in 

 the pursuit of their calling. The delineation of our charts has attained such a high 

 degree of boldness in style and clearness as to give them a reputation of excellence 

 among all nations. Although our maritime surveyors have accomplished mighty 

 work in the examination and the correctly laying down a very extensive pro- 

 portion of the coasts on our globe, there remains a large amount of interesting 

 work for our attention ; for the " unsurveyed world " is of considerable extent — new 

 routes are opened up to the commercial world in unfrequented seas, which demand 

 the careful examination of the skilled marine surveyor. 



During the period now before us, our kindred across the Atlantic have taken up 

 a very high position in this branch of hydrography : the admirable manner in which 

 the Cnited-States Coast Survey has been conducted is exemplary to all nations as 

 regards its liberal provision, as well as for the comprehensive and systematic 

 method of execution in carrying out this great work. I would point to the 

 reports made to Congress for the last quarter of a century as containing matter of 

 surprising interest both to the mariner as well as to the scientist ; every new 

 object is recorded with minute precision, an enormous amount of information is 

 collected on meteorology, magnetism, tides and currents, as well as on hydrography 

 and geography; also discussions on the causes as to the increase and decrease of 

 coral-reefs, besides important additions to natural history ; above all, the complete 

 investigation and information regarding the great Gulf-Stream. It is a work 

 nobly organized and executed, truly worthy of a great maritime nation. Here 

 I deem it as opportune for this Section to accord a tribute of praise to the works of 

 Captain Maury, of the United States. He has honoured us with his presence at 

 the meetings of this Association, and favoured us with the benefit of his informa- 

 tion — his elaborate charts of the trade-winds of the Atlantic Ocean and his laborious 

 work on ' Winds and Currents ' being a combination of science and experience 

 which have contributed to abridge our long ocean voyages ; the production of his 

 marvellous work, the ' Physical Geography of the Sea,' in which the " wonders of 

 the deep " led the way to a general interest on the subject of oceanic physics, and 

 its style and language are so engrossing that it is attractive to the general reader, and 

 takes its place as a work of literary excellence. 



