lessons may be taught as to the relation of the local weather conditions which prevail in the vicinity of the school, and those of other portions of the country, by comments on newspaper despatches concerning gales along the coast or on the lakes, and resulting damage to shipping; of snow blockades and stalled trains; of severe thunderstorms and tornadoes; of hot waves and sunstrokes, or of cold waves and the destruction of crops or fruits by the frost. The scholars should be encouraged to bring into the class any comments on such phenomena as may be of interest in the work. Such of these newspaper clippings as are of the most value may be pasted in the space reserved for the “Remarks,” where they may be referred to by succeeding classes; and in this space also may be pasted at the end of each week the barograph and thermograph sheets, if these instruments are in use at the school. CHAPTER III. These observations may usually be profitably undertaken in the later grammar and in the high school years. The instruments described, while all desirable, are by no means all necessary, and no teacher should postpone the establishment of a course in observational meteorology for the reason that a complete set of first-class instruments cannot be secured at the start. If the school is provided with a psychrometer, there will be no need of the ordinary thermometer, because the psychrometer gives the true air temperature. It is well, however, to have both stationary wet and dry-bulb thermometers, in the shelter, for ordinary school use, and also a sling psychrometer for use in the meteorological _field work_ which forms an important part of the more advanced instrumental work in meteorology. The sling psychrometer may, of course, be used simply as an ordinary sling thermometer. The simple form of mercurial barometer, without vernier and without attached thermometer, described in Chapter II, will be found the best barometer for general school use. The standard barometer, described in this chapter, is too expensive and too complicated to come into extended use in our schools. Full instructions concerning the care, the reading, and the corrections of the standard mercurial barometer are published by the Weather Bureau, and to these instructions teachers who have such an instrument are referred. (See Appendix B.)