SeXTaNT aiId prism aYIo do M pass survey. 80 
march, read off and plotted from b on the field-sheet; bearings are also 
taken to objects, such as X, Y, on either side of the route, and plotted ; 
the point X haying also been observed from A, is now fixed. The march 
is again taken up in the direction b c' until a point c is reached, at which 
the road bends to the left, the distance b c laid down, and so on until camp 
B is reached. At B, observations should be made in the evening for time 
and latitude; and in the morning, observations similar to those which 
b o 
have been made at A. Should the camp be near one of the points 
observed to from A, the distance and true bearing of such point from B 
should be determined, with a view of fixing its position. At certain 
camps the longitude should be found by lunar distances, or other methods, 
to serve as a check on the traverse-survey. Distances on the line of march 
may be measured by counting or timing the paces of a man, or by counting 
or timing the paces of a horse, mule, camel, &c., whose length of step is 
