Ixxii Education Committee. — Examination Papers, 1868. 
No. 4. Explain the effects of burning on the chemical constitution 
of soils ; and point out the precautions (from a chemical point of 
view) which must be taken in applying this agency and the reasons 
for them. 
No. 5. In what combinations occur usually the following elements, 
in soils ; P., S., K., Na., Si., Ca., Mg. 
No. 6. Describe in general terms what takes place when the follow- 
ing liquids percolate through a fertile soil : — 
Solutions of Nitrate of Soda. 
„ Sulphate of Ammonia. 
„ Chloride of Potassium. 
„ Chloride of Sodium. 
„ Superphosphate of Lime. 
Town Sewage. 
No. 7. Describe the chemical properties of the chief constituents of 
milk, and a good plan of analysing milk. 
No. 8, How would you proceed in determining the nutritive value 
of new articles of food, such as palm-nut meal, foreign grains, feeding 
cakes, &c. 
QUESTIONS IN MECHANICS. 
Time allowed for answering these Questions, 10 a.m., to 1 p.m. 
No. 1. A rope from a windlass, having a strain of 2640 lbs. upon 
it, passes along a headland and round a pulley, drawing a steam plougli 
across a field ; the direction of the plough is at right angles to the 
headland. 
Required the strain in lbs. on the shank of the anchor which keeps 
the pulley in position. 
Also give the metliod of findinpi; it in the case of any angle other 
tlian a right angle, and \vork it w here the direction of the plough is 
4-5 degrees to the headland. 
No. 2. The diameter of the safety-valve of a steam boiler is 25- 
inches, the length of the lever from the centre of the fulcrum to that 
of the weight is 26 inches and the distance of the centre of the fulcrum 
from that of the valve is 3^ inches ; the weight applied to the lever 
is 20 lbs. 
Required the pressure per square inch in the boiler to be in 
equilibrium with the weight on the valve. 
No. 3. A loaded cart weighs 5000 lbs. ; the diameter of the wheels 
is 4 ft. 9 in. 'J'hc cart has to be drawn into a barn over a thi-eshold 
35- inches high. 
Required tlic force in lbs. to draw the cart over the threshold, 
fraction excluded. 
