Combining a clock with other adjustable dials, a watchmaker in a California aircraft plant has devised an instrument with which the navigator of an airplane, after setting a problem in the chronometer, can obtain the plane’s position in fifteen seconds. The instrument is expected to be of great value on long flights, as on bombers where success depends on exact calculations of position. A vernier at the top of the clock records minutes and seconds of time with the corresponding conversion of arc during elapsed time of observation. Calculations and corrections are set by movable dials, the navigator “shoots” the sun or stars and by checking the vernier against the clock reading, he can read his position to the second.