138 GEOGRAPHICAL SURVEYS AND EXPLORATIONS. 



superior size and stability. It can be slung with its stand on a mule or pony without 

 difficulty andean be used with cavalry. But each assistant should also be provided with 

 a lighter, smaller, and more portable table, which can be conveniently slung- on a man's 

 back ; a really portable table of this sort has yet to be devised, as also the best kind of 

 stand. 



Each officer or assistant should also be provided with the following minor instruments 

 and books, viz. : — 



Two trough needles, 1 sight-rule, 1 telescope or binocular, 1 aneroid barometer, 1 

 prismatic compass and stand, 3 thermometers for determining the boiling point of 

 water, ordinary air thermometer, 1 Gunter scale, 1 beam compass, 1 small box 

 instruments, 1 Shortrede's log tables, 1 Chambers's log tables, 1 auxiliary tables 

 for facilitating the computations of the Great Trigonometrical Survey. 

 The officer iu charge should carry in addition — 



One Abney's level, 1 set scales, 1 maximum and minimum thermometer, 1 nautical 

 almanac, 1 prismatic subtense instrument, 1 parallel ruler, 1 pantagraph, 

 J manual of surveying, 2 sets measuring tapes (steel), 1 perambulator, lamps 

 for observing, 1-G" heliotrope, 1 chronometer watch, 1 portable sun-dial, spare 

 compass and drawing pens. 

 ****** 



5. In addition to the usual personal baggage scale, the following will be required for 

 the headquarters camp — 



( (ffice tent .-- - 150 lbs. 



„ table - - - - 20 „ 



Stationery and small instruments - 160 „ 



Maps and data - - 50 „ 



For public followers 1 sepoy's pal, holding 17 persons, or its equivalent in smaller 



tents. 



These recommendations were made on the following assumptions 

 regarding the nature and extent of the work to be undertaken by 

 the survey officers : — 



A. — That a large extent of country, embracing several thousand square miles, may 

 be either actually visited or sketched from a distance, during the course of a campaign. 



15. — That every surveyor should be equipped to act independently, if necessary. 



C. — That there may be no opportunities of visiting any portion of the ground twice, 

 and therefore that all surveying must be done pari passu with the more or less rapid 

 movements of troops along the main lines of communication. 



D. — That maps are to be compiled and traced in the field, so that all the work of the 

 survey can be put into the hands of the generals concerned as speedily ;:s possible. 



K. — That the topographical operations are not to consist merely of surveys of the 

 lines ol* route, but are t.. embrace as much as possih!'- of the surrounding country, and 

 must therefore be executed on a trigonometrical basis ; consequently, that the surveyors 

 must always work together iu pairs, one doing the tri-mgulation, the other the topo- 

 graphical sketching; for, when the troops are marching rapidly, it is impossible for any 

 single man to do both, and each is required to supplement the other. 



F. — That the survey office with the army will be the general depot for all maps of 

 the country which may be published by the Surveyor-General's Department and be 

 supplied for distribution as required. 



G. — Tint the sanctioned allowance of baggage and equipment for every officer iu the 

 field who is employed ir transport, commissariat, or any other duties which oblige him 



