A Ni-based superalloy contains 13. The wind velocity measuring device includes a wind velocity measuring unit that measures a wind velocity of air, and an air circulating unit that circulates a portion of the air blown to the cooled objects. A composition comprising volumetric ratios of ethanol:water:propylene glycol selected from those in the range of from 10-70:10-30:20-80, respectively, having a combined total of 100 is also provided.