This has been accomplished by the employment of a translatable deflecting prism to which the scale is directly attached.Īs originally produced, however, the range finder fell ' far short of fulfilling expectations, due principally to the difficulty of making the optical parts, which are of exceedingly novel design.
In the working out of the design for the finder it was sought to make the accuracy of the instrument, so far as possible, independent of the precision of such mechanical parts as micrometer screws or any delicate mechanism which might become worn or deranged through hard continued service. The invention of the range finder was the outcome of a public advertisement, issued by the British War Office in 1888, for an instrument which would fulfill certain specified conditions. The principal claims of superiority of the Barr-Stroud finder over other instruments of similar nature are its portability, absence of all delicate mechanism, ease of manipulation and the fact that it obviates all necessity of the services of more than one man to establish a measured base.
#Ithaca 1911 to navy oakland series#
THE accompanying illustrations convey a very fair idea of the appearance of the Barr and Stroud range finder, at present used in the British army and now undergoing a series of tests by officers of the United States army, stationed at Fort Sam Houston, Texas, with the view of determining what advantages, if any, it possesses over the Weldon instrument as used by our own government. It is easily made, inexpensive, can be used in many ways and will be found especially useful in moving stones or other heavy objects, prying timbers apart, opening boxes, wrecking small buildings and in a hundred other ways in which a small, easily handled crowbar can be used to advantage. returned at the other end to form a claw which can be used for It is practically a small crowbar, pointed at one end to form a pinch. ONE of the handiest tools in working around a house or small shop is a goose-neck, such as shown in the accompanying sketch.
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