A Manual for Practical Surveyors: Containing Methods Indispensably Necessary for Actual Field OperationsJ. W. Moore, 1854 - 108 páginas |
Otras ediciones - Ver todas
Términos y frases comunes
1st offset 40 perches angle ABC angles of deflection angular point back sight bearing of A B bearing of CD bring the sights bring the telescope circumferenter clamp the lower closing line correction course degrees determine difference of variation equal error feet kerfs last station let the needle line A B line CD line joining line run lines of survey lower plate magnetic magnetic bearings marked tree method n² m² n³ m³ nier nonius compass nonius plate parallel perpendicular distance Place the instrument present bearing PROPOSITION quired random line right angles right line run a line run the line Set the instrument set the vernier sights to bear subtracted surveyor tance tang telescope to bear tion trapezoid traverse table tripod true bearing true line unclamp vernier to zero
Pasajes populares
Página 80 - All the interior angles of any rectilineal figure, together with four right angles, are equal to twice as many right angles as the figure has sides.
Página 17 - ... more than half through its thickness, and intersecting each other at right angles at the centre of the block...
Página 58 - A line which is to be established from the course only, should be re-run at nearly the same season...
Página 58 - It must, therefore, be a matter of uncertainty 'whether we have the correct bearing of the line, even when the change for years has been ascertained with the utmost care.
Página 57 - The variation of the magnetic needle in declination, is subject to much irregularity, in some instances increasing, in other decreasing, and some years having scarcely a perceptible motion.