five o'clock
Between petting and feeding , the collie spent a busy hour among his comrades-at-arms . He was to stay with the `` Here-We-Comes '' until the following day , and then carry back to headquarters a reconnaissance report . At four o'clock that afternoon the sky was softly blue and the air was unwontedly clear . By five o'clock a gentle India-summer haze blurred the world 's sharper outlines . By six a blanket-fog rolled in , and the air was wetly unbreatheable . The fog lay so thick over the soggy earth that objects ten feet away were invisible . `` This , '' commented Sergeant Mahan , `` is one of the times I was talking about this morning -- when eyes are no use .