Modernwarshavenotmateriallychangedtherelativevaluesorproportionsoftheseveralarmsofservice:infantry，artillery，cavalry，andengineers。Ifanything，theinfantryhasbeenincreasedinvalue。Thedangerofcavalryattemptingtochargeinfantryarmedwithbreech—loadingrifleswasfullyillustratedatSedan，andwithusveryfrequently。Soimprobablehassuchathingbecomethatwehaveomittedtheinfantry—squarefromourrecenttactics。Still，cavalryagainstcavalry，andasauxiliarytoinfantry，willalwaysbevaluable，whileallgreatwarswill，asheretofore，dependchieflyontheinfantry。Artilleryismorevaluablewithnewandinexperiencedtroopsthanwithveterans。Intheearlystagesofthewarthefield—gunsoftenboretheproportionofsixtoathousandmen;buttowardthecloseofthewaronegun;oratmosttwo，toathousandmen，wasdeemedenough。
Sieges;suchascharacterizedthewarsofthelastcentury，aretooslowforthisperiodoftheworld，andthePrussiansrecentlyalmostignoredthemaltogether，penetratedFrancebetweentheforts，andleftasuperiorforce\"inobservation，\"towatchthegarrisonandacceptitssurrenderwhenthegreatereventsofthewaraheadmadefurtherresistanceuseless;butearth—forts，andespeciallyfield—works，willhereafterplayanimportantpartinwar，becausetheyenableaminorforcetoholdasuperioroneincheckforatime，andtimeisamostvaluableelementinallwars。
ItwasoneofProf。Mahan’smaximsthatthespadewasasusefulinwarasthemusket，andtothisIwilladdtheaxe。Thehabitofintrenchingcertainlydoeshavetheeffectofmakingnewtroopstimid。Whenalineofbattleisoncecoveredbyagoodparapet，madebytheengineersorbythelaborofthementhemselves，itdoesrequireanefforttomakethemleaveitinthefaceofdanger;
butwhentheenemyisintrenched，itbecomesabsolutelynecessarytopermiteachbrigadeanddivisionofthetroopsimmediatelyopposedtothrowupacorrespondingtrenchfortheirownprotectionincaseofasuddensally。Weinvariablydidthisinallourrecentcampaigns，andithadnoilleffect，thoughsometimesourtroopswerealittletooslowinleavingtheirwell—coveredlinestoassailtheenemyinpositionoronretreat。Evenourskirmisherswereinthehabitofrollinglogstogether，orofmakingalunetteofrails，withdirtinfront，tocovertheirbodies;and，thoughitrevealedtheirposition，Icannotsaythatitworkedabadeffect;sothat，asarule，itmaysafelybelefttothementhemselves:Onthe\"defensive，\"thereisnodoubtoftheproprietyoffortifying;butintheassailingarmythegeneralmustwatchcloselytoseethathismendonotneglectanopportunitytodrophisprecautionarydefenses，andactpromptlyonthe\"offensive\"ateverychance。
Ihavemanyatimecreptforwardtotheskirmish—linetoavailmyselfofthecoverofthepickets\"littlefort，\"toobservemorecloselysomeexpectedresult;andalwaystalkedfamiliarlywiththemen，andwasastonishedtoseehowwelltheycomprehendedthegeneralobject，andhowaccuratelytheywereinformedofthesateoffactsexistingmilesawayfromtheirparticularcorps。Soldiersareveryquicktocatchthegeneraldriftandpurposeofacampaign，andarealwayssensiblewhentheyarewellcommandedorwellcaredfor。Onceimpressedwiththisfact，andthattheyaremakingprogress，theybearcheerfullyanyamountoflaborandprivation。