Experiments and Discoveries . T7 
« The following observations were made at sea by Mr Fos- 
ter, under my superintendence and occasional assistance. The 
instrument used was an azimuth compass, made by Messrs W . 
and T. Gilbert of London, lent to me by the makers, at the 
suggestion of Professor Barlow. It is so constructed, that the 
observer reads off the angle at the same time that he observes 
the object: it is in other respects, also, admirably suited for prac- 
tice, not only on such occasions as this, where much delicaOy is 
required, but also in surveying and in piloting ships, by means 
of charts and bearings. The azimuth compasses at present 
supplied to his Majesty’s ships (1822) are altogether unfit for 
any of these purposes, even the most common. 
(Signed) “ Basil Hall.” 
Lieutenant Foster, the gentleman spoken of above, and who 
made the greater number of the observations under the superin- 
tendence of Captain Hall, gives in this place a detailed statement 
of all his experiments : they are continued from England, be- 
low Cape Horn, and hence, again, to the magnetic equator, on 
the western coast of America. They occupy several pages in 
Mr Barlow’s report, but they are afterwards brought into a ta- 
bulated form, in order to bring them more collectively under 
the eye of the reader, and the better to compare them with each 
other, and with the observations of Captain Flinders ; the au- 
thor having added two columns for this purpose, one containing 
the dip of the needle at each place of observation, from Han- 
steen’s chart, and the other shewing the end of the needle, that 
was drawn forwards, according to the indication of the plate, in 
order to ascertain how far the deductions agreed with those of 
the distinguished officer above alluded to. This Table, and 
the author’s remarks upon it, must conclude our notice of these 
important observations. 
