• An Eigel’s centigrade thermometer, graduated up to 150 degrees (302 degrees Fahr. ), which seemed to me too much or too little. Too much if the internal heat was to rise so high, for in this case we should be baked, not enough to measure the temperature of springs or any matter in a state of fusion.
• An aneroid barometer, to indicate extreme pressures of the atmosphere. An ordinary barometer would not have answered the purpose, as the pressure would increase during our descent to a point which the mercurial barometer 6 would not register.
• A chronometer, made by Boissonnas Jun. , of Geneva, accurately set to the meridian of Hamburg.
• Two compasses, viz. , a common compass and a dipping needle.
• A night glass.
• Two of Ruhmkorff’s apparatus, which, by means of an electric current, supplied a safe and handy portable light. 7