about midnight
I do n't know what other ingenious fakes you have added . The visible bluish light from the tube is designed , I suppose , to hoodwink the credulous , but the dangerous thing about it is the invisible ray that accompanies that light . Mr. Haswell sat under those invisible rays , Prescott , never knowing how deadly they might be to him , an old man . `` You knew that they would not take effect for hours , and hence you ventured the prediction that he would be stricken at about midnight . Even if it was partial or temporary , still you would be safe in your prophecy . You succeeded better than you hoped in that part of your scheme . You had already prepared the way by means of a letter sent to Mr. Haswell through Dr. Burnham .