D-LUX2 with Real non AI Mount lens Sample Photo 318996 By keninejr

This would be a psychrometer, with the middle thermometer giving the shaded air temp, and the nearer one with the sock that would be moistened to determine the effect of evaporation (why that one's called the wet bulb), with the chart used to find the humidity from the difference in the readings. I haven't seen one like this with the third thermometer which I'll guess indicates the effect of exposure to the bright sun... 112°? Wow, and about 103 in the shade. (former USAF weather guy here!)