Elements of Plane Trigonometry, Surveying and Navigation

A B C base line bearing calculation called centre chain chords column compass computed convenient coördinates corner cosecant Cosine Cotang course deflection degrees departure determined diagonal difference of latitude difference of level direction divided draw drawn earth east employed equal example extended feet field book find the remaining given line graduated limb height horizontal plane hypothenuse instrument length line A B longitude manner mark means measured Merid middle latitude miles objects observed obtain offsets parallel perpendicular plane sailing plane triangle plot principal meridian quadrant radius right angles right triangle river road rods scale secant series of triangles ship side A B sine and cosine spirit level square station subtracting supposed surface survey tance Tang tangent telescope Theodolite tion township triangle ABC trigonometrical vernier vertical yards