Sentence:  I was looking in the direction of the lightship off and on from the time we first sighted her. I could not be mistaken in such a matter as a <WSD>flare</WSD>-up light. By a <WSD>flare</WSD>-up light I mean a large bright light waved in the air, something like a torch dipped in resin and waved about. I am prepared to say that any person who has sworn that she shewed a <WSD>flare</WSD>-up light from the lightship while the "Kanagawa Maru" was passing has perjured himself. 
Meaning of the word marked with <WSD> tags:  A source of brightly burning light or intense heat.