Probably the most mysterious disappearance of recent times is that of the United States collier transport _Cyclops_, which sailed from Barbados for Baltimore March 4, 1918, and has not been heard of since. The official information respecting this important vessel is fragmentary and disconnected. In December, 1917, she reached Bahia, Brazil, and was ordered to take on a cargo of manganese at Rio de Janeiro for the return voyage. The Navy Department exchanged several messages regarding her cargo with the commander in chief of the Pacific fleet, and, on February 7, the latter sent the following message concerning damage to one of her engines: "Starboard high pressure engine found to be damaged on board U.S.S. _Cyclops_ during passage Bahia, Brazil, to Rio de Janeiro. Board of investigation reports accident due to loosening of nuts on follower ring studs, resulting in breaking of follower ring. Cylinder is broken into two parts by plane of fracture passing from inboard upper edge down and outboard at angle of about 45 degrees. Cylinder cover and piston ring broken and piston rod bent just below piston, which is damaged. So far as now determined, responsibility seems to be upon engineer officer watch Lieut. L.J. Fingleton, who did not stop engines nor report noise. Board recommends that new cylinder, piston rod and piston, piston rings and follower be manufactured. That cylinder cover be repaired by welding upon return United States. Repair of cylinder by welding believed possible. Can not be made here. Engine compounded and vessel will proceed thus when loaded." She reached Barbados safely and began her voyage from there to Baltimore. Being overdue, the Navy Department sent the following message to the naval stations at Key West, Charleston, Guantanamo, Navy Radio San Juan, and the U.S.S. _Albert_: March 22, 1918. "U.S.S. _Cyclops_ sailed from Barbados March 4 for Baltimore. Now about ten days overdue. Endeavor communicate _Cyclops_ by radio and ascertain location and condition." The following day the Navy Department sent a similar message to the commander of Squadron I, Patrol Force, Atlantic fleet. On March 24 the station at Charleston, S.C., reported that at intervals for twenty-three hours messages by radio had been sent in an endeavor to locate the _Cyclops_, but without success. Commander Belknap directed that calls be continued, and on March 26 the Navy Department sent the following message to the Governor of the Virgin Islands: "U.S.S. _Cyclops_ sailed from Barbados March 4 for Baltimore. Has not yet arrived. Have you any information regarding this vessel passing St. Thomas?" The reply was "No information regarding U.S. S. _Cyclops_."