A tapered section and a flange section which constitute reinforcements are provided on mounting members to which a blower is to be attached. In general, a document library comprises a database, a special \u201cdocument library\u201d file system folder and the documents in that folder. The third lubricating oil composition of the invention comprises an ether oil as a base oil, a specific amount of an anti-wear agent comprising a neutral phosphoric ester andor a neutral phosphorous ester, and an antioxidant, so that this composition is free from change of properties over a long period of time and is favorable as a watch lubricating oil. An on-board fuel tank is fluidly coupled to the fuel passageway. The corrosion resistance of the tungsten overlay is considerably improved. The irradiation history sensor and detection method advantageously employ Dy-containing nanocrytals residing in a transparent host.