PRACTICAL EXERCISES IN GEOGRAPHY 71 



Longiiade. — Difference of longitude (introduced under any name 

 that is suggested by the pupils when talking freely of the relative 

 positions of places on a rotating globe — the technical name to come 

 in later) can be determined between two schools in any one of the 

 three historical methods. As Strabo employed an eclipse of the 

 moon to determine the relative easting or westing of certain points 

 bordering the INIediterranean, so school children in different joarts of 

 the country may employ a lunar eclipse today to determine the rela- 

 tive positions of the meridians on which their homes are situated, 

 previousl}^ determining their local solar time, and subsequent!}' com- 

 paring the recorded time of any phase of the eclipse b}'' correspondence. 

 As governmental parties a hundred j^ears ago made chronometer ex- 

 peditions between neighboring national capitals, so school children 

 may today send a watch from one school to another by express, and 

 thus make a very good determination of difference of longitude. As 

 modern observers employ the telegraph for time comparisons, even 

 if separated b}' the wbole breadth of a continent or of an ocean, so 

 school children may toda}' delegate some of their number to go to a 

 telegraph office and send "time signals " from their watch (previously 

 set to local solar time by their own observations) to an expectant 

 part}'^ at the other end of the line. The two parties may have to wait 

 half an hour or so to get the line " clear," but such a trifling delay 

 should be no obstacle to success ; and even such delay may be 

 avoided if a long-distance telephone is used ; then the time signals ma}'' 

 be counted aloud by one party and directly heard by the other. 

 Surely it is not the lack of capacity on the part of the pupils; it is 

 not the expense involved ; it is not the difficulty or the uselessness 

 of the work that keeps such practical experiments as these out of our 

 schools. What is the real difficulty in the way of their introduction ? 



Indoor Exercises. — Practical exercises of another kind on the earth 

 as a globe may be performed indoors.* A meridian section of the 

 earth as a sphere and as a spheroid may be drawn to scale in order 

 to show how vanishingly insignificant tlie ])olar flattening really is_ 

 Geographically, its value is negligible in a high-school course, however 

 important and interesting it is in astronomy and however valuable it 

 is historically as a i)roof of the earth's rotation. The height of the 

 highest mountains, the depth of the deepest oceans, the mean alti- 

 tude of continents, the mean depth of sea floors, and the rate of in- 



♦ Sevenil of those exercises luive been suggcstcil to iiic by Mi \V. II. Snydir, i>r \\ iiii'(!.stor 

 Academy. 



