Agricultural Education — Examination Papers, 1885. ciii 
5. Explain what is meant by the diffusion of gases. How is it 
shoAvn that gases do not all diffuse at the same rate? Find the 
relative rates of diffusion in the atmosphere of carbonic acid gas and 
aqueous vapour. 
6. "What is galvanized iron ? Explain the advantages of so treat- 
ing iron. 
7. What are the distinguishing characters of compounds of 
manganese ? Mention points of resemblance of such compounds to 
those of iron. What is potassium permauganate and what are its 
2iroperties ? 
8. State the general constitution of animal oils, and how they differ 
from mineral oils and oil of turpentine. What is the cause of driiiiui 
of oils? 
9. Explain the relations between starch, sucrose, glucose and lactose. 
What are the conditions under which lactic acid is formed ? 
EX.\MINATION IN MENSUEATIOX AND SUEVEYING. 
Maximum Numbeb of Mabks, 100. Pass Numbee, 50. 
Thursday, May \4^i}i, from 2 p.m. till 5 p.m. 
1. State three rules for finding the area of a triangle from 
different data. 
The three sides of a triangle are AB = 7-51 feet, BC = .j6-4 feet, 
C A = 623 feet ; calculate its area, and the length of the perpendicular 
let fall from A upon B C. 
2. State the rules for finding the area and circumference of a 
circle, when the diameter is known. 
How many cubic yards of earth have to be moved in sinking a 
well 5 feet in diameter, and 80 feet deep ? Estimate the number of 
bricks required to line the well, assuming that each brick is 
9 inches X 4^ inches X 3 inches, and that the bricks are laid with 
the 3-inch edge vertical, and the 4i-inch edge at right angles to tlie 
side of the well. 
3. A piece of timber is 40 feet long ; the circumference at one end 
is 1.50 inches, that at the other end is 50 inches ; calculate tlic 
number of cubic feet in it, assuming its form to be that of a frustum 
of a cone. Estimate its weight, assuming its specific gravity to 
be 0-8. 
4. Define a prismoid, and state the rule for finding its volume. 
Stones are heaped against a vertical bank to a height of 10 feet ; 
the heap is on level ground, and its base is a rectangle 100 feet long 
in a direction parallel to the bank, and 20 feet at right angles to 
