Also telometer. [f. TELE-, TELO-2 + -METER. Cf. F. télémètre, 1852, in Cosmos, II. 222.]
1. An instrument for ascertaining the distances of objects: applied to instruments of various kinds used in surveying, and in military operations. Acoustic telemeter, one in which the distance is ascertained by observing the time occupied by sound in traversing it.
1860. G. Richardson, Patent Specif., No. 2102. This improved instrument (which in commerce I intend to call a telometer).
1869. Pall Mall G., 31 Aug., 4. Of two batteries coming into action, the one with and the other without a telemeter, a difference of about a minute in opening fire would make the difference between accurate shooting and shooting by guesswork.
1888. A. W. White, in Encycl. Brit., XXIII. 126/1. Telemeter, or Rangefinder…. Telemeters have been made on three distinct principles, and classified as acoustic, optical, and trigonometrical respectively. Ibid., 126/2. The Nolan range finder … was the first telemeler used by the British artillery.
1900. H. M. Wilson, Topogr. Surv., xiii. 274. The gradienter is used as a telemeter in measuring horizontal distances in two ways.
attrib. 1900. H. M. Wilson, Topogr. Surv., 236. The stadia, telemeter, or subtend system [of measuring distances].
2. An apparatus for recording the readings of any physical instrument at a distance by means of an electric current; a general term including the teleanemograph, telebarometer, telethermometer, etc. (see TELE-).
1891. in Cent. Dict.
Hence Telemetric, Telemetrical adjs., pertaining to, connected with, or serving as a telemeter; also Telemetrograph, an instrument for measuring and drawing plans of distant objects or areas (Sci. Amer., Supp., 1 Aug. 1885, 7975).
1871. W. N. Jeffers, Naut. Surv., 101. Telemetrical Telescope of Gautier.—Although familiar with most of the telemetrical apparatus, the writer has seem nothing which promises to be more useful to the naval officer than this instrument.
1877. Knight, Dict. Mech., 2513. Another form of telemetric marine-glass…. The telemetrical telescope of Captain Gautier.
1900. H. M. Wilson, Topogr. Surv., xiii. 282. The range-finder furnishes a … rough telemetric method of obtaining a fairly accurate measure of inaccessible distances.
