XXII. A Method of determining the Time with Accuracy, from 

 a Series of Altitudes of the Sun, taken on the same side 

 of the Meridian. By Major-General Sir Thomas Bris- 

 bane, Knt. F. R. S. E. 



(Read Feb. 2. 1818J 



Having for a number of years been constantly moving about, 

 in situations where I could not convey large astronomical in- 

 struments, I have repeatedly tried to what extent of accuracy 

 and consistency I could arrive with the smaller ones. The re- 

 sults have convinced me, that a great deal of accuracy may 

 in that way be obtained ; and that the sextant is an instru- 

 ment, which, if perfectly understood, would be in higher esti- 

 mation, and more general use, than it is at present. The ob- 

 servations I am about to submit, were made with a ten inch 

 sextant of Troughton's, divided on platina to 10", (No 1200). 

 The manner of using it, which I am now to describe, is what 

 I have pursued for a great length of time, both at sea and at 

 land, and I can recommend it as uniting simplicity with accu- 

 racy, and at the same time as serving to discover errors, if they 

 happen to exist. Our climate does not admit of obtaining equal 

 altitudes very frequently, but I conceive that the mode which 

 I wish to see adopted, will admit of equal accuracy, and I am 

 Vol. VIII. P. II. 3 R justified 



