MILITARY ENGINEERING. Military engineering is officially stated to be that branch of engineering science applied by engineer troops in the field to the emergencies of mod ern warfare in order to protect and assist troops, to ameliorate the conditions under which they are serving, to facilitate locomotion and communication and whenever the occasion requires to act as purely combatant troops. In the performance of these duties engineers are trained and equipped to supplement or amplify by scientific measures the efforts of combatant troops in the services mentioned below and such other special services of an engineering nature as may arise and are beyond the tech nical training of combatant troops, or such 'as require the use of engineering implements and material not supplied to combatant troops. The following services are executed under the supervision of engineer officers by engineer troops, by details from other troops, by civilian labor or by any combination of these means as the particular circumstances may require: I. The service of reconnaissance, including tactical reconnaissance, engineering reconnais sance, surveying, mapping and sketching, pano ramic sketching, photography, drafting and map reproduction.
2. The service of castramentation, including the selection, laying out and preparation of camps, the reconnaissance and municipal and sanitary engineering incident thereto, and the installation, operation and maintenance of water-supply systems.
3. The service of fortifications, pertaining both to the attack and the defense and includ ing the selection of defensive positions when not in the presence of the enemy; rectification of and assistance in the selection of such posi tions in the presence of the enemy; the loca tion, design and construction of the more im portant field works; assistance in and super vision of the construction of hasty defenses wherever possible; the supply of tools and ma terials, and the reconnaissance, demolitions, water supply and communications incident thereto.
4. The service of sieges, pertaining both to the attack and defense and including the selec tion and location of defensive lines, lines of investment and siege works, the construction of saps, mines and counter-mines; the operation of searchlights; preparation for and assistance in attacks, counter-attacks and sorties; organi zation of captured points, and the supply of tools and materials.
5. The service of demolitions, including the carrying out of all work of this nature au thorized by the commander and not within the scope of other troops.
6. The service of battlefield illumination, in cluding the supply and operation of search lights and other means of battlefield illumina tion.
7. The service of general construction, in cluding the location, design and construction of wharves, piers, landings, storehouses, hospitals and other structures of general utility in the theatre of operation.
& The service of communications, including the construction, maintenance and repair of roads, ferries, bridges and incidental structures; the selection and preparation of forts; the con struction, maintenance and operation of rail ways under military control and the construc tion and operation of armored trains.
9. Special services, including all municipal, sanitary and other public work of an engineer ing nature which may be required in territory under military control.
Fire Action.—To comprehend the subject of fortifications it is imperatively necessary to know and understand the effect of fire both from small arms and artillery, destructive forces quite different in action from those against which the engineer must ordinarily pro tect his works. To shoot straight, to direct a projectile true to its target, is a feat of engineer ing just as much as the accurate adjustment and pointing of a theodolite in a geodetic sur vey. Rifle fire which dominates a certain space and prevents the enemy from occupying it is just as effective as that which strikes his men, and the greater the space which can thus be occupied by fire action per unit volume of fire the more efficient is that fire. Artillery fire has of late become a most important factor in mod ern tactics with its great increase and accuracy and bids fair almost to revolutionize battle tactics and the art of fortification. By the ap plication of indirect fire and spotting a battery can take up a position of safety and systemat ically search out the landscape.