242 
LITTLEHALES. 
Chronometer slow on Greenwich mean time, 2 minutes 
39 seconds. 
The hour-angle of aArietis is 4- 2 h 59 m 17*, or 44° 49' 15" 
W., and we are enabled to find by inspection that a body in 
this hour-angle with a declination of 4- 22° 59'.5 must be in 
altitude 38° 48'.5 and azimuth N. 57° W., to an observer in 
the stated geographical position. 
The hour-angle of a Canis Major is 2 h ll m 24 s , or 32° 51' 
E., and we are enabled to find by inspection that a body in 
this hour-angle with a declination 4-5° 29' must be in alti¬ 
tude 55° 56'.2 and azimuth N. 74° E. to an observer in the 
stated geographical position. 
The difference between these two deduced altitudes is 17° 
7'.7, and this subtracted from the measured difference of 
altitude set down in the statement of the problem gives the 
means, when taken in connection with the two deduced 
azimuths, of reducing the estimated place of observation to 
a point on the required line of position by means of the 
following formula: 
7 . d A h A* 4- A x A 2 — A, 
(U = ~~2~ sec - V sec - ~ l ~2 — 1 C0SGC - —~— 9 —- 
in which d A = the difference of longitude between the as¬ 
sumed geographical position and the re¬ 
quired point of the line of position. 
d A h~ the difference of the two differences of alti¬ 
tude as found by measurement and by 
inspection. 
<p = the latitude of the assumed geographical 
position. 
and A x and A 2 — the respective azimuths of the observed 
bodies. 
