Written by Royal Geographical Society
Hints to Travellers, Scientific and General, Vol. 2
by Royal Geographical SocietyThe minimum requirement of instrumental observations by a traveller is the reading twice daily of the barometer and of the dry and wet bulb thermometers, to ascertain the temperature and humidity of the air, also the reading once daily, in the morning, of the minimum thermometer which has been exposed all night, and on days in camp of the maximum t..