NOTES AND QUERIES.

Otago Witness, Issue 3215, 27 October 1915, Page 47

NOTES AND QUERIES.

Questions tor reply In coming Issue to be received not later than SATURDAY night. Questions will NOT be replied to through, the post.

Irene. —The Blue Cross flag as a symbol in ambulance work is to the horse what the Red Cross is to the soldier—-in otherwords, the Blue Cross flag is the veterinary .symbol. (2) The flags were decided upon at the Geneva Convention, an international conference held at Geneva, Switzerland, in 1864, for the purpose of improving the condition of wounded soldiers hi the field. Farmer.—The value of the receipt stamp for a bill over £2 is still on© penny, but on and after November 1 the value will be twopence. Racquet.— For the single-handed game of lawn tennis the court is 27ft in width and 78ft in length. Halfway between the side lines and parallel to them is drawn the half-court line, dividing the space on each side of the net into two equal parts. On each side of the net at a distance of 21ft from it and parallel to it are drawn tho service lines. For the double-handed game the full court is 86ft wide by 73ft long. Within the side lines at a distance of 41ft from them and parallel to them are drawn the service lines. E. W. 8., Mataura. —(1) The best way to clean a whit© straw hat is first to remove all trimming and brush off all dust, then make a paste of sulphur and lemon juice and apply with a small brush (an old tooth(brush does very well). Put in the sun to dry, and when dry brush well once more. (2) A navy blue suit may be renovated by sponging with strong ammonia water, ■which both. removes spots and takes away the shining appearance. The suit should then be pressed by laying a damp cloth over it and pressing with a hot iron, taking care to lift the iron before the steam has ceased rising, as this brings the nap up again. Very shiny ©pots may be rubbed very gently with sandpaper. When sponging it is best to use a piece of the same material if possible. M. C. —Tanning Furred Skins: Wattle bark is a good tanning agent for fur skins, and if properly used should give good results. The skins should be scraped clean on the inside, and then laid as flat as possible in a strong decoction made by boiling or steeping the crushed bark in water. A large square, zinc-lined packing case is a good xeccptablo. The skins_ should be thoroughly covered by tho liquid, which taust either be changed once a week or boiled anew and skimmed. Large skins take up to six weeks to tan well, but opossum skins will not require more than e, month, A quicker method which can be

used if wattle bark is not obtainable is to paste the scraped skin, after soaking in warm water for an houi’, with a mixture of equal quantities of borax, saltpetre, Glauber salts, and water. About hoz of each should be sufficient for opossum skins, but more for larger ones. Then double the skin together, flesh side inwards, and place it in a cool place for 24 hours, at tbe end of which time it should bo washed clean, and treated in the same way as before, with a mixture of loz of sodium carbonate (washing soda), £oz borax, and 2oz hard white soap; these must be melted slowly together without being allowed to boil. The skin should then be folded together again, and put in a warm place for 24 hours. After this, dissolve 4oz of alum, Boz of salt, and 2oz of sodium carbonate (baking soda) in sufficient hot water to saturate tbe skin; the water used should be soft, preferably rain w'ater. When this is cool enough not to scald the hands, the skin should be immersed, and left for 12 hours; then wring it out and hang it up to dry. The soaking and drying must be repeated two or three times, till the skin is soft and pliable, after which it may be rubbed with fine sandpaper and pumicestone to obtain a smooth finish. Inquirer, Round Hill, wants to know if in a game of euchre with hearts as trumps and the ace of spades is led can the ace of diamonds take that trick. Certainly not. The knave of diamonds becomes the left bower, but no other diamond is affected because of hearts being trumps, and only a heart can take the ace of spades. Water Power, Otapiri Gorge. — Mr H. M. Davey, consulting engineer, replies:—“l should have recommended a 12 foot wheel, but your gearing is, I see, suitable for the 8 foot one, and, in fact, is all on the small size even for that; but no doubt you should be able with the storage you speak of to work all you need, as the water is accumulating all the time when you are not, working. Well, now, the water-wheel should run at about 18 revolutions per minute, and I understand the tooth-wheel that you call the big one lias 70 teeth, so you will have 1:' x 7» = 1260 teeth passing per minute. Now the pinion having 13 teeth, you get I*o —r- 15 = 84 revolutions for the intermediate shaft per minute. Then you say that the speed of the machine goes about 130, or perhaps more, and so we may as well say about 140 revolutions per minute as the speed. This then gives you . 8-t : 140 1(i : 19 inches full, which would be the diameter of the new pulley you have to get or make for the countershaft. You calculate thus:

Do not have your belt too short, as if yon do, it has to be much tighter, and so there is more friction. Black pine or totara would seem to ibe the best, though I have heard some say that white pine stands well in the water; but I do not know if this is so. It is generally very bad for buildings, and so has a bad name here, but you will know if it stands in the weather or not You will have a sketch sent you in a day or two, and if there is anything more after that that you want to know, write and ask, for it is no good working in the dark—that is, doing things you only half understand. Your race or fluming w r ould have to be 2ft to 2ft Bin wide and about Ift Bin deep. You may not need it quite as large, but it would be a great trouble if it were at all too small. A water-wheel of the diameter of yours should have about 17 'buckets, and as it makes 18 revolutions per minute, you get 17 x 18 = HOfi buckets passing per minute. As you may need as much as 400 cubic feet of water per minute, you should prepare for that quantity. That means rather more than 1 cubic foot per bucket, so tho capacity of each bucket should be at least eight to nine gallons, or rather more, so as not to have unnecessary splashing. Somewhere about Bft wide would be ample, and you may as well prepare for a little more power than you need at present if it can be got.