The respondent cement company had engaged Kleinsteuber, doing business as the Kleinsteuber Boiler Works, to make some alterations on the barge. Sauer and Wilberding were in the employ of Kleinsteuber, and were performing such work as was assigned to them by the cement company under instructions of its vice president and general manager. The libels allege that the explosion was caused by the negligence of the respondent in failing to use reasonable care to provide the deceased with a safe place in which to work, in that respondent, after having used the barge for oil, failed properly to clean out its hold so as to prevent the generation of gases. The record discloses certain accepted methods for removal of gases under such circumstances. They are, first, to scrape the sides of the tank and remove all oil possible, then to exclude the gases by filling the hold with water or steam. None of these things was done.