Royal Society. 217 



tical calculation has been so far successfully applied, that they might 

 form a portion of the subjects of study here, if we had clear and con- 

 venient treatises upon them." (Preface, pp. xvii and xviii.) 



We may also quote the following from a really practical work by 

 one of the most distinguished Cambridge men of the present day, 

 whose example, it is much to be regretted, has not been followed 

 by more men of his own university : — 



" I am not without hopes, that, in addition to its principal object 

 of giving a scientific and systematic form to its subject, the results 

 of the volume which I now venture to present to the world may be 

 found a useful addition to mathematical studies in general, by afford- 

 ing simple illustrations of the application and interpretation of for- 

 mulae, and by suggesting new subjects for problems, and for further 

 investigation." (Willis's 'Principles of Mechanism,' Preface.) 



IMr. Phear's ' Hydrostatics' is not sufficiently copious and expla- 

 natory. He (like so many other Cambridge writers) has sacrificed 

 clearness to brevity. But there are some good examples, and the 

 work, like all the others, is admirably printed. 



Of Mr. Barnard Smith's ' Arithmetic and Algebra,' we need say 

 no more than repeat the encomium of Dr. Peacock, and recommend 

 it as the best book we know on the subject. We may state that the 

 ' Arithmetic ' is published separately for the use of schools. 



XXVII. Proceedings of Learned Societies. 



ROYAL SOCIETY. 

 [Continued from p. 149.] 



May 24, 1855.— The Lord Wrottesley, President, in the Chair. 

 nPHE following communications were read : — 

 -■- " On a Decimal Compass Card." By James M. Share, Esq., 

 Master R.N. 



The mariners' compass-needle having of late years received great 

 improvements, I am of opinion it is high time the card, as at present 

 arranged, should take its place by the side of such things as are 

 superseded by others better adapted to the advancing spirit oi" the 

 times. 



I venture to make an attempt to innovate on an old custom, by 

 suggesting the substitution of a compass card containing thirty-six 

 points of ten degrees each — every degree being one-tenth of a point. 



By the use of this card the mariner will avoid the constantly re- 

 curring trouble of turning degrees into points, and vice iwrsd. 



The ship's course having been worked out in degrees, the devia- 

 tion and local attraction have but to be applied to adapt it to the 

 decimal steering card, thus rendering the " traverse table for 

 points " no longer necessary to those steering by it ; the course 

 N. 35° E. being the same as " north three and a half points east," 

 &c. The same remark applies also to astronomical bearings, azi- 

 muths, amplitudes, &c. 



Should the decimal card be adopted, the old-fashioned method of 

 " boxing the compass," which takes young people so long to become 



Phil. May. S. 4. Vol. 10. No. 65. Sept. 1B55. Q 



