150 'Mathematical Puldkatmis. — iVe«/ Block. 



prompts ine to state, that tlie Nautical Almanac for 1821 has 

 been out of print nearly three months, and the new edition is 

 not yet issued from the press. Durin;^ this period many valuable 

 ships have sailed on distant vovages ; niiie of the East India 

 Company's ships to my knowledt^e : six of these from 1200 to 

 1350 tons burthen, all destined first to India and afterwards to 

 China: several of these have not been al)le to proi'ure a Nauti- 

 cal Almanac for 1821 ; and as some of them will be obliged to 

 proceed from India by an eastern passaf>e to China, they will 

 have to navigate in the Pacific Ocean early in 1 82 1 destitute of 

 a Nautical Almanac for that year, if thov do not obtain one prior 

 to their departure from India, which is verv improbable : and it 

 is possible some of these valuable ships may be compelled to na- 

 vigate afterward from China to England, without possessing that 

 essential requisite to the safety of navigation. 

 Feb. 22, 1820. An Observer. 



MATHEMATICAL PUBLICATIONS. 



To Mr. rUloch. 

 Sir, — I perfectly concur with the opinion given in your useful 

 Magazine for November 1819, page 368, of the advantage arising 

 from the mathematical periodical publications, and feel confident 

 that the books there noticed, have conjointly with others, and 

 particularly the verv respectable and well conducted Gentleman's 

 Mathematical Companion, uniformly afforded a stimulus to ma- 

 thematical intjuiries, which could not fail to produce mathema- 

 ticians of the first rank. But the reason of my troubling you at 

 present, is to express mv regret at not observing the name of the 

 Gentleman's Mathematical Companion, which commenced in 

 1799 and was antmally and regularly continued to the present 

 time, mentioned in an article apparently written for the laudable 

 purpose of drawing the student's attention to a good collection 

 of such publications. As I have been for many years a corre- 

 spondent to various ])eriodical productions, and am in consequence 

 well acquainted with them, I beg to recommend the above-named 

 work to the notice of those who may l)e desirous to possess au 

 advantaceous selection, through the medium of your Philoso- 

 nhical Magazine. With the idea of replncing what appears to me 

 to be an omission in your valuable pages, 



I remain with respect your obedient servant, 



A Correspondent. 



NEW BLOCK. 



Specification of a new Block for ivhich a Patent has been 



obtained. 

 The advantages in the carcase over that of the common block, 



arc. 



