We had not been engaged in our reading very long when at the far end of the arch I noticed a twinkling light. "Kool esclop!" shouted one of the boys, at the same moment doucing the glim and bolting with his companion, leaving me in the dark with my upset beer bottle and my douced candle, forming a spectacle which seemed to arouse suspicion on the part of our friend the policeman, whose light it was that had appeared in the distance.
Source: wiktionary