May 23, 1859.] OBITUARY.— RAPER. 249 



Having tlins virtually abandoned the active line of bis profession, 

 he betook himself very assiduously to the cultivation of its scientific 

 departments ; and his efforts were crowned with such success that 

 his name must ever be enrolled among the improvers of hydro- 

 geographical knowledge. In 1 832 he was selected by the Admiralty 

 to form one of a committee to improve the method of measuring the 

 tonnage of ships ; and the Report, which was principally drawn up 

 by him, was equally clear and convincing. 



In connexion with this Society, of which he was one of the earliest 

 members, has Lieutenant Eaper repeatedly served on our Council. 

 In 1840 he published his * Practice of Navigation,' a book of sterling 

 merit, for which we awarded him the Gold Medal in the fol- 

 lowing year. That this prompt appreciation of the work was a 

 just one, was evidenced by its being soon afterwards adopted in the 

 Eoyal Navy, and by the ships of the East India Company. More- 

 over the third edition of it was noticed from this chair by Admiral 

 Smyth, in 1850, as well generally for the useful additions engrafted 

 on* its pages, as particularly for its admirable and well-organized 

 table of ' Geographical Positions ' of all the places on the globe ; 

 and which, with infinite skill and labour, he increased from 2 ,.300 

 to no fewer than 8,800. In this edition he also introduced those 

 significant symbols for the admission of great local information in 

 a limited space, which promise to render chorographic details of 

 readier reference than under any other form ; and the whole is so 

 stamped with worth as to prove unequivocally the industry, method, 

 and varied attainments of the author. 



This highly useful book was to have been followed by a second 

 volume containing a theoretical discussion of all the data and details 

 contained in the first — in fact, to prove analytically what he had 

 expounded synthetically. As this work advanced it assumed in- 

 creased importance, from combining astronomy, geodesy, mechanics, 

 geometry, and physics ; but, unfortunately, he did not live to com- 

 plete it. His manuscripts are left, but from their unarranged state 

 and nature, their publication is rendered very unlikely. 



Lieutenant Raper became a Fellow of the Eoyal Astronomical 

 Society in 1829, and not only served upon its Council repeatedly, 

 but for several years filled the important post of Secretary, with 

 credit to himself and advantage to the Society. He maintained 

 his habitual cheerfulness and continued his labours to the last; 

 insomuch that in July, 1858, he communicated to the Astronomical 

 Society his improved method of * Clearing a Lunar Distance-.* 



u 2 



