Chapter Xi. =obstacles=--Object--Necessity for 1173-1193

Obstacles--Location--Abatis--Palisades--Fraises-- Cheveaux de Frise--Obstacles against Cavalry--Wire Entanglements--Time and Materials--Wire Fence--Military Pits or Trous de Loup--Miscellaneous Barricades-- Inundations--Obstacles in Front of Outguards--Lessons from the European War--Wire Cheveaux de Frise--Guarding Obstacles--Listening Posts--Automatic Alarms--Search Lights.