Fig. 433.—Sling case for drawings.

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894.—Chronograph.—For the observation of stars in transit for the purpose of taking longitude, a dead-stop watch or chronograph is most useful. This can now be had in combination with an otherwise fair going watch at a very moderate price.

895.—Outfit of a Surveyor for Work in a New Country.—The ordinary items of strong, dust-coloured woollen clothing, good boots, saddle, firearms, etc., do not come within the province of this work. The instruments he will require will depend partly upon the nature of the country and the kind of work to be done. If for prospecting only, light instruments are commonly selected—the sextant, or box sextant with glass artificial horizon, good pocket chronometer, telescope, aneroid barometer, prismatic compass, and clinometer. If a general survey is to be made, the first instrument of importance is the theodolite, the 4 or 5-inch being the most usual. With this, pickets, land chain and arrows, a steel tape for testing, and a linen tape. If for survey in mineral districts, a good mining-dial is required, with all accessories of chains, etc. If for railway work, a 5-inch theodolite, a good level, staves, pickets, clinometer, and prismatic compass. In all cases, field-books, drawing instruments, supply of paper, drawing boards, squares, parallel rule, pencils, Indian ink, colours, stencil plates, and other articles for office use, of which the established optician or trader will give full information from his experience, or general reference may be taken from any complete catalogue of such instruments.

INDEX

A B C D E F G H I L M
N O P Q R S T V W Y