Scientific and Useful.

Lake Wakatip Mail, Issue 1526, 9 April 1886, Page 4

Scientific and Useful.

BLCCTBIC APPLICATION. The lateat feat in the way of ekctrio lighting ia the application of cell storage to piai oa. The ctse of the inatrument conceals the materials for an illumination lasting over ten hours. to itg hiking paper. A plan for rendering paper aa touch aa wood or leather has been recently introduced 011 the Continent; it consists in mix'ng chloride < f rinc with the pulp in the course of manufacture. It has been found that tho greater the degree of concentration of tli« zinc solution the greater will b«» the toushnes* of tl e paper. It can be used for making boxes and for roofing. PREHISTORIC IMPLEMENTS. An interesting discovery of bronze hatchets and other warlike inatrument* has been made in Llantwit Major, Glamorgsnsbire. As a number of workmen were engaged digging up a foundstion for builiing, they discovered three spearheads, six hatchets, hko celts, and cereral other interesting relics, which were concealed under an ancient wall Some bones were also discovered, ard the whole matter is under investigation, and a further search is being organised. STIEL VAILS. It is predicted by an American pi| or that in the course of the next four years the steel nail will have as completely supplanted the iron nail as the steel rail has its iron predecessor. Already one half of the nails manufactured in Wheeling are made of steel, and the machinery and plant necessary for ther manu--1 facture are being set up at every nail centre t and at nearly every nail factory. It is said that, under present conditions, steel nails can be made about ten cents per keg cheaper than those made of iron, even where the manufacturer has to purchase his ingots. NATUBAL OAS. From present indications, (says the Mechanical World) it seems doubtful if the supply of natural gas, which has produced such a marvsllous effect on the industries of Pittsburg within the past few months, is likely to be permaneut. Several of the mills along the Alleghany river have changed the hours of wcrk because of a deficient fl jw from the wells. One of the largest now commences work at eleven a.m. instead of three a.m. as here ofore, the supply of gas in the morning being insufficient to meet the heavy demand necestarj to heat the many furnaces which are lighted at that time. THB TKMPBRATCHE 0* THB ATLANTIC. The captain of the steamer Olympin has been accustomed for rorae time past to make daily observations of the temperature of the surface water of the ocean during his transAtlantic voyages. On his last westward trip, in the early part of November, he found the average temperature of the Atlantic along the 40th parallel to be about 72 5 deg. from Gibraltar to 68 deg. west longitude. In crossing the Gulf Stream, however, the warmth wbs considerably greater. In previous years the average temperature was only about 70 deg. for the month of October, and considerably less than this in November, so that this year the water seems to have been at least three degrees above the temperature of former years. This difference is slight, but it shows a backwardness in the approach of winter compemating in a measure for our tardy spring. DRIVING AT NIGHT. How to illuminate a road in front of the horses in driving at night is an important matter. The usual side lamps on carriages, or the attaching of a lantern to tbe dash board, fail to reflect tbe light where it is most needed, and the suspending of a lantern to the front axle is objectionable for many reasons, but it is the best plan for shedding tbe light where it is most wanted that we have seen tried. But a Philadelphia physician suggests the attaching of tbe lanterns to the breast collar of the harness, which be says he has tried with perfect satisfaction; and he has evidently bad some experience with the ordinary method of lighting, for he says tbe various forms of dash lights are pretty much the same, in that they put the light just wbere it is not wanted, illuminating the horse's tail and hips agd tbe buggy thills with a brilliance quite unnecessary, which intensifies tbe blackness of the shadow cast by them just wbere one most wishes to sec clearly.—Scientific American. DEAD BLACK FOB OPTICAL INBTBt'JtBSTS. Those who are the possessors of optical instruments bate, at some time or other, been in need of a dead black paint or varnish for brass work, such as tubes, diaphragms,J he. All the formulir and receipts given in books are unsatisfactory because of the vagueness. The following can be relied upon to give a first rate dead black, and it is easily made i Take two grains of lampblack,, put it it into any smooth, shallow dish such as a saucer or a email butter plate, add a little gold size, and thoroughly mis the two together. Jast enough gold rise should be used to hold the lampblack together; about three drops of such size as may be had by dipping the tip of a lead pencil about half an inch into the gold si*e will be found right for the above quantity of lampblack j it should be added a drop at a time, however. After the lampblack and sise are thoroughly mixed and worked, add 24 drops of turpentine, and again mil and work. It is then ready for use. Apply it thin with a camel's hair brush, and when it is thoroughly dry the articles will have aa fine a dead black as they had when they came from the optician's hands.

" AKCHOB" 'BO6TS. On (he night of Friday, January H, there was an anchor froet in the Cherwell such aa haa net been known for twenty jean, according 10 people who have lived at a mill on the river, (Clifton Mill, near Ajnho Station) fur that psriod. In a mild form the phenomenon it fairly frequent there. The most marked effects are seen in comparatively still water. Thus, in the mill pond, where the current is stopped by the mill during the night, the whols stream becomes semi-viscous. Koota beneath the water, the brickwork at the sides of the mill pond, Ac., are teen to be coated with ice beneath the water aa (ar down as can be seen, and between this ice and the surface ice-crj stall form, not in a sheet or block, but interlaced loosely, like snow crystals in adrift The mass thus formed blocks the channel, and it is B#id that water coming upon it from above will rise in level and flow over it, aa over a solid obstruction. This I have not seen myself. When the mill is started, at first the water will hardly flow paat the wheel j but at length the crystals are forced to the aurface, where they remain iu floating maaacr, under which the water flows aa usual. The surface is not covered with a sheet of ice in these frosts. In a broad, shallow ditch at right angles to the river, where tte water is comparatively still, similar effects could be seen > the pebbles at the bottom coated wiih ioe and the water filled with loom crystals. * One consequence of the ice forming on this occasion waa that the flood gates were frozen down on Friday evening, so that they could not be drawn up at usual, and the rirer overflowed during the night. In the morning, when they wen at last raised, the water would hardly flow through, as already mentioned in the case of the water wheel.—T. Hands, in Falun,