Few of the problems suggested call for continuous routine observation at fixed hours. They require, on the other hand, an intelligent examination of ordinary weather phenomena, with special reference to discovering their explanation. In most of the problems a small number of observations will suffice. Under the supervision of the teacher, different problems may be assigned to the several members of a class; or several scholars may work on different parts of the same problem, exchanging records in order to save time. All the scholars should have a general knowledge of the results which have been obtained from the observations made by the other members of their class. The teacher will use his discretion in arranging the order of the problems, and in selecting those that are best suited to the season in which the work is done, to the locality in which the school is situated, and to the facilities and apparatus at command. Although the variety of accessible problems is less in city schools than in country schools, much may be done in the city as well as in the country.
The opportunities for carrying out such observational work vary so much in different schools that it is impossible to give specific instructions, which shall be available in all cases. Some general suggestions are therefore given, which the teacher may supplement by more detailed instructions framed to fit the particular circumstances of each case.
A review of the headings of the different problems shows that a very general correlation exists among them, whereby the subjects of every heading are associated with those of nearly every other.
In other words, every weather element is treated as a function of several other elements. It follows from this that the variety of work here outlined is more apparent than real, and that many problems which appear from their wording to be entirely new are in large part rearrangements of problems previously encountered.
APPENDIX B.
THE EQUIPMENT OF A METEOROLOGICAL LABORATORY.
A. Instruments.
Exposed Thermometer (United States Weather Bureau pattern), with brass support, $2.75.