henry kater invented the floating collimator.
henry kater invented the floating collimator.
who invented the floating collimator?
henry kater
floating collimator









































floating collimator was an early collimator widely used in astronomical observations. it was invented by an english physicist and astronomer captain henry kater about 1825.









































his collimator was meant to replace a level, or plumb-line, in astronomical observations, and to furnish a ready and perfectly exact method of determining the position of the horizontal or zenith point on the limb of a circle or zenith sector. its principle is the invariability, with respect to the horizon, of the position assumed by any body of invariable figure and weight floating on a fluid.
floating collimator
floating collimator consists of a rectangular box containing mercury, on which is floated a mass of cast-iron about twelve inches long, four broad, and half an inch thick, having two short uprights or y's of equal height, cast in one piece with the rest. on these is firmly attached a small telescope, furnished with cross wires, or, what is better, crossed portions of the fine balance-spring of a watch, set flat-ways, and adjusted very exactly in the sidereal focus of object glass.
floating collimator