Page:Handbook for Boys.djvu/87

66 corner places. Then take the triangle along the bank in the direction of C until. C' D' are in line with the sight object,

with the pegs B C. Then the length of the long base B C' will equal the distance from B to X.

To measure the space between two distant objects, D and E. Line A B on one, then move this right-angled triangle until F G is lined on the other, with B G in line with G H. B G equals the space between D and E then.

If the distance is considerable, it may be measured sometimes by sound. Thus, when a gun is fired, a man is chopping, or a dog barking, count the seconds between the sight and the hearing of the sound, and multiply by eleven hundred feet, which is the distance sound travels in a second.