ON SCIENCE IN SCHOOL CERTIFICATE EXAMINATIONS. 493 



II. Physical Section. 



A. Astronomy. 



The following subjects should be taken in class. Further voluntary work 

 may be directed and encouraged by the School Science Club. 



1. Revision of previous work. The fundamental importance of sidereal 

 time. The astronomical clock. Fixing positions of stars by right ascension 

 and declination. Construction of star-charts. (In connection with these the 

 use of the polar and meridional gnomonic projections may be either taught or 

 applied from the geography course.) 



2. Plotting of monthly course of the moon upon a cylindrical projection 

 (compare Second Year, II., A., 4), right ascensions and declinations being taken 

 from ' Whitaker's Almanack.' The path of the moon thus shown to be approxi- 

 mately a plane inclined to the ecliptic. 



Plotting on enlarged scale of paths of moon and sun about the times of 

 new and full moon. (It is best to use the gnomonic projection, since the paths 

 are then straight lines.) Conditions for eclipses. 



3. The variation in distances of sun and moon deduced from varying 

 observed diameter. (Data from 'Whitaker's Almanack.') Perihelion and 

 aphelion ; perigee and apogee. The orbits of earth and moon elliptical. Calcu- 

 lation of eccentricities. 



Regression of moon's node ; influence on dates of eclipses. The precession 

 of the equinoxes. 



Simple theory of tides. 



4. The planets. The Ptolemaic and Copernican theories. 



The relative distances of the planets from the sun and of the moon from 

 the earth. Measurements of absolute distances by parallax, transit of Venus, 

 &c. Kepler's laws. 



B. Geology. 



The following subjects may be expected to be taken during this year in 

 geography lessons : — 



1. The stratigraphy of the home region. One or two lessons based on 

 evidence acquired on field-excursions or reported by individual pupils, museum 

 collections, &c. Thus, in London a clear idea should be given of the geology 

 of the Thames basin from the northern to the southern chalk height.s, the 

 evidence of borings for artesian wells, &c., being examined. The probable 

 geological history of the region. 



2. Extension to neighbouring regions : for example, in London to the Weald, 

 Surrey, Hants, and the Isle of Wight. 



3. Outline of the geological structure of typical regions, such as Wales and 

 the northern coal-fields of England. 



C. Mechanics. 



The following subjects are to be regarded as territory common to the 

 courses in science and mathematics. Much (or all) of the work may be taken 

 in mathematics lessons. 



1. Uniform and variable velocity (linear and angular), average velocity, 

 velocity at a given moment; distance-time and speed-time graphs. 



Two cases of special importance : (i) Falling bodies and projectiles. The 

 vertical distance fallen found to vary with the square of the time ; hence the 

 average, and therefore the final, vertical velocity must be proportional to the 

 time. Value of ' g.' (ii) Pendulum motion. Here, since the time of swing is 

 constant for small arcs the average velocity is proportional to the amplitude. 

 It follows that the velocities at all corresponding moments, including the 

 moment of mean position, are proportional to the amplitude. 



2. Velocity as a vector. Relative veJocity. Vectorial representation of 

 changes of velocity. Utilisation of the property given in 1 (ii) to measure 

 changes of velocity produced by collision of swnging balls (Goodwill's ' Vector 

 Balance '). 



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