NOTES AND QUERIES.

Otago Witness, Issue 3201, 21 July 1915, Page 51

NOTES AND QUERIES.

Questions for reply in coming issue to be received not later than SATURDAY night. Questions will NOT be to through the post. Wayback. —The sample of material you sent for identification was submitted to Professor Park, who has reported that it is a pulverulent form of kaotin clay. Clays of this kind have little or no commercial value in New Zealand. Their presence does not indicate the occurrence of other metals or minerals of value. Reader. —Your best plan is to communicate with the Under-secretary for Immigration, Wellington. There is /no local office in Dunedin. The Government arranged some time ago for reduced fares, but how far this arrangement may be interfered with by the war we do not know. Seven Years’ Reader,—(l) Mr Howden suggests .that the best way to extract seed from pine cones is to place the cones in a slow oven; the cones - open up, and the seed falls out. (2) Sow in September, planting in drills or beds in the-'ordinary way to the depth of lin. Learner wishes to know the way to dance the set dances. We can supply the figures of the set dances, but to learn to dance them he should either purchase a book of, instruction or get some friends to learn him the steps. Cadet. —As to the distance the Defence Department can compel a person to attend drill, what you should ask yourself is: How can I best obtain instruction and drill. At present many business men after an arduous day’s work travel more than the statutory four miles to drill with the National Reserve. 'Pansy. —The individuals to which you refer nave not advertised for more than 12 months, so we cannot give their address. Electricity, Ranfurly.—Mr H. M. Davey, consulting engineer, replies:—“A pelton wheel would scarcely bo suitable under the conditions you name. You might send the approximate length of the level pipe, as that would make all the difference, and also state the number of lights that you would need, and also if you would.be likely to want heating or power as well—now or taker on. Also the quantity of water available. The fall you mention would seem to point to a low pressure turbine as the most suitable machine for your jiurpose; but it would be bettor to know above particulars before deciding." H. B. M., Gore. —Mr Davey replied:—“We have again consulted in the matter of the boiler setting, and Mr M'Lintock writes as follows: —There is no doubt that the firegrate is built in too low to suit the fuel you use; as although you say it is 22in from the bars to the bottom of the boiler, it is more at all points except the centre line, owing to its curvature, and so much heat is as lost, especially towards and at the wings. The grate might therefore be raised as much as, say, Gin or Tin, with advantage; and this should give much better results. The probable reason that the seed or coal- is not consumed on the wing bars is that there is faulty combustion, owing to the construction of the bridge. It would certainly be an - advantage to reduce its height at the sides, and not for it to follow the curvature of the boiler, but to have it horizontal or. the top edge. This would - allow the escaping gases to get away raoro freely and not .be retarded as they appear to bo at present, preventing the adequate combustion at the wing be If the boiler is under-powered, the sij;e of the fire-grate. could be reduced. Tile combustion chamber is large, but it ougM not to lower the efficiency. If you remember, the reducing of the sides or ends d the bridge was recommended in the fiist reply. With regard to your final inquiry,

I have no doubt that either of us would be glad to see you if you called when you were in town ; at any rate, I may say, for myself, that I would be pleased to see you if you cared to call.”