Y

Yarrowdale, prisoners from, II, 294-296

Ypres, air battles at, I, 265, 266-275;
  First Battle of, I, 104-106;
  Canadians at, I, 248-276;
  Germans use gas projectiles, I, 242;
  second battle of, I, 240-276;
  in battle of Picardy, III, 168

Ysaka Maru, sunk, II, 282

Yser, Germans trying to cross the, I, 116-117;
  last ditch, I, 108

Z

Zeebrugge and Ostend, bottled up by British, III, 101-118

Zeppelins, raid England, I, 375-383

Zimmermann, Herr von, I, 35;
  views of, I, 21-22