backstaff Definition

heliometer, almucantar, macrometer, angular distance, pantometer, holometer, forestaff, cathetometer, magnetograph, statoscope, gravity meter, chartometer, rhysimeter, astrometer, magnetic north, apparent magnitude, heliometry, tellurometer, spherograph, pilot balloon, anemography, dynactinometer, hypsometer, system of measurement, pyrheliometer, anemograph, angulometer, mean solar day, lapse rate, absolute magnitude, isotach, aerometer, cosmolabe, altitude, spectrohelioscope, standard candle, anglemeter, dioptometer, y level, thermoscope, datum plane, nephoscope, wind rose, weather map, temperature scale, machmeter, hypsometry, meteorometer, armil, anemoscope, contour line, meteorograph, light meter, isohyet, dygogram, isothermobath, measurement, exposure meter, hygrostatics, sidereal time, hydrodynamometer, geothermometer, line of longitude, fundamental quantity, selenodesy, lucimeter, ephemeris time, map projection, vaporimeter, megameter, loxodrome, magnetic dip, right ascension, sidereal day, pluviograph, noematachograph, mercury barometer, isothermobathic, spherometer, psychrometry, anemo, absolute space, ozonometry, small circle, evaporometer, declinator, hydrobarometer, vacuum gauge, weatherglass, cryometer, haemoscope, evection, colatitude, phonometer, universal time, radiation pyrometer, artificial horizon, isobarometric, true anomaly, longimetry,