Captain HalFs Notice of a Voyage of Research. S5T 



dent observations of Jupiter's satellites, and particularly corre- 

 spondent observations of moon culminating stars, as well as 

 of eclipses, would be very serviceable to the cause of nautical as* 

 tronomy. It is desirable also to ascertain how far the method 

 of occultations can be practised at sea, and to what magnitude 

 of stars it may be useful to carry the computations in the nau* 

 tical almanack. Men of science who have turned their atten- 

 tion to these pursuits, would probably furnish the commander 

 of such an expedition with many hints for inquiry, which can- 

 not be suggested by a practical man. There have as yet been • 

 no regular and systematic trials made at sea of the relative me- 

 rits of the various instruments contrived for measuring the 

 moon's distance from the sun and stars. Practical men are di- 

 vided between the sextant, Troughton's circle, and the repeat- 

 ing circle, and much needless expence is often incurred by per- 

 sons who can ill afford such outlay. The readiest, as well as 

 the most exact methods of making lunar observations and chro- 

 nometers mutually assist one another, have never yet been pro- 

 perly stated. 



NAUTICAL SUPPLIES. 



A wide field for the diligence of any officer so employed, is 

 presented under this section, and, if duly explored, could not fail 

 to prove highly beneficial to the country. The peculiar resources * 

 of the distant parts of the globe are extremely little known ; 

 indeed up to a recent period, it was of no great importance that 

 they should be so. Now, however, that the trade of the eastern 

 seas and of South America is thrown open, and that with China 

 and Japan will soon undoubtedly follow, it becomes of the first 

 consequence that our traders should have some further knowledge 

 of the resources of ports far from home, independently of all ob- 

 jects merely commercial. A ship may be dismasted in the middle 

 of her voyage, or spring a leak, or run short of provisions ; — her 

 crew may become sickly ; — she may lose her anchors and cables, 

 or split her sails ; and it may become essential to the very ex- 

 istence of the whole enterprize, that some re-equipment should 

 take place. But it is quite possible, that, under such circum- 

 stances, the master of the ship may be entirely ignorant in what 

 direction he ought to proceed ; he may, and in fact very often 

 does, make the most ruinous mistakes. The remedy for this 



