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. . . GENERAL FIELD AND OFFICE PROCEDURES FOR INDIREeT DISCHARGE MEASUREMENTS 9 hinged stadia rod may aIso be used. A rod level for plumbing the rod is recommended for accuracy as well as speed. Range poles are not necessary but they are often useful for obtain- ing alinement, for taping, or for locating cross sections in photographs. A steel tape and engi- neer's folding rule graduate in hundredths of a foot are needed. A hand level is useful in re- connaissance.. All surveying instruments are precision in- struments which must be handled with care. Give particular care to protecting the transit while enroute in an automobile. Wrap or set the carrying case in some soft material to pro- tect the instrument from shock. A mauled and dented carrying case is a sign of abuse. In brush or woods, carry the tripod under an arm with the instrument forward where it can be watched. Do not drive stakes with level rods. Set aside an old level rod for sounding in water. Use graphite in the slip joints of the three- section Chicago rod. Clean and oil steel tapes after use. Check and keep all instruments in good adjustment at all times. Level rods and engineer's rules are subject to error, particu- larly at the joints. Check them periodically. A boat is needed at times for stream crossings or soundings. Desirable materials are marine plywood, aluminum or fibre glass. A boat should preferably be at least 14 feet long. A light boat may be carried on top of the car, using a raek; a heavier boat requires the use of a trailer. A motor of at least 10 horsepower should be used and kept in good condition. A hand level, plastic tape (for flagging), a taping weight, an axe, and plenty of stakes, are needed; also nails, cloth measuring tape, crayon, paint, and chisels for marking high-water marks and reference points. A weight should be available for sounding from bridges; standard sounding weights may be used. The standard stream -gager's tagline or a heavier boat tagline is ideal for eross-sec- tioning. For soundings from a boat a wading rod, range pole, or an old level rod may be used. Camera equipment is a necessary part of .the field equipment; stereocameras are recom- mended. It is also desirable to have a small drawing board and drafting machine, or at least some triangles and a protractor, for field draft- ing. Special equipment is occasionally needed for unusual circumstances. Where high-water marks are high in trees or on a steep bank, a ladder has been found to be timesaving. When necessary to work in rainy weather, a tractor- type umbrella can be held in a 6- foot pipe driven in the ground beside the instrument. In dark woods a flashlight is useful for lighting up the level rod and reading the transit vernier. On large-scale surveys where the men may be some distances away or across a wide river, two-way "walkie-talkie" radios, or transceivers, have been used advantageously. Short-range 1~- watt output transceivers weighing less than 2 pounds serve well. Flexible antennas, recharge- able batteries with charger, and carrying cases are useful accessories. Boots and waders are usually needed, and wet-weather equipment such as raincoat and hat, add to the engineer's comfort. If both the rodman and the instrumentman wear distinc- tive type clothing, such as red coats, shirts, hats, or vests, they can locate each other in a mini- mum of time in heavy woods. Life jackets should always be worn in boats. The kapok type is preferred to inflatable vests. The following is a suggested checklist for items which may be included when assembling equipment for an indirect-measurement trip. Prepamrory: Reconnaissance notes Notes on high-water mark locations Field notes ot previous survey Reviews ot previous measurements Maps Station descriptions Bench-mark descriptions Survey: Transit Tripod Level rods Level-rod level Hand level Engineer's folding rule or 600ft steel tape Notebook and Dote paper Stakes Hatchet, axe Macbete, brush cutter Marking equipment: Nalls, tape, crayon, paint, chisel Field drafting equipment