. Building and repairing railways . ry. TEE RECONNOISSANCE. 55 In making a reconnoissance the most directline should always be examined first, unless thereis positive knowledge of some insurmountabledifficulty. Should this be the case, of course theterritory to the right or left will be short route, other things being equal, should not, however* betoo quickly aban-doned. Rocky val-leys, giving the im-pression of difficultand expensive con-struction, have of-ten been summari-ly avoided, when af-terward they haveproved to be thecheapest the gen-eral direction of apropo
. Building and repairing railways . ry. TEE RECONNOISSANCE. 55 In making a reconnoissance the most directline should always be examined first, unless thereis positive knowledge of some insurmountabledifficulty. Should this be the case, of course theterritory to the right or left will be short route, other things being equal, should not, however* betoo quickly aban-doned. Rocky val-leys, giving the im-pression of difficultand expensive con-struction, have of-ten been summari-ly avoided, when af-terward they haveproved to be thecheapest the gen-eral direction of aproposed line cros-ses ravines or pas-ses from a summitinto a valley, fol-lows a stream forsome distance andthen ascends another stream to a divide, it willbe found advisable to look for a high line andkeep on the summit, following a spur out to thestream, cross the stream by a viaduct to a spuron the opposite side and again take the locations need careful comparison as to firstcost and cost of operating and maintenance, and. *>- dial with leather case and straps. 56 BUILDING AND REPAIRING RAILWAYS, in making a reconnoissance the engineer will givethem most careful consideration.* Mountain and valley lines are not the mostdifficult to construct as is generally greatest errors of location have been madeon open prairies and foot hills of mountains onaccount of stopping exploration when a locationgiving the desired grades curvature and cost wasfound without endeavoring to find a better. In making a reconnoissance the engineer will,as he proceeds, make calculations and notesshowing the probable nature of the material to behandled i. e., whether earth, loose rock, hard panor solid rock, and the percentages of each at di^ferent cuts. This will be approximate only, buthis observation will afford a basis upon which toestimate cost. He will note also the probablequantities of excavation, embankments and bridg-ing per mile; the fuel supply; possibil
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