Barometer for Farmers
In one of his letters, Humboldt says that a Barometer should be considered as necessary on a farm as a plough: but farmers generally prefer to trust in the moon and other exploded nonsense to purchasing a reliable instrument that would repay them tenfold. A substitute, called Leoni’s Prognosticator, consists of a vial full of a clear liquid, in which swims a snowy substance. In fine weather that substance lies on the bottom, but before a storm it rises to the surface, with a tendency to the side opposite the quarter from which the storm is coming. The substances used are kept secret. An ordinary barometer indicates the density of the atmosphere. Leoni’s instrument evidently indicates its electric state, and for that reason we are of opinion that it is a better instrument to prognosticate the weather. The following is a substitute that will not cost more than 1s., and for aught we know it may be the identical thing itself. Dissolve some camphor in alcohol and throw into the solution some soda; the camphor will be precipitated in snowy flakes; collect these by passing the mixture through a filter and put them in a vial with clear alcohol, in which as much camphor as it would take has been dissolved. Cork it, place it where it will not be disturbed, and examine it every morning and night. This is termed a Storm-glass.