SCIENCE AMI INVENTIONS

North Otago Times, Volume CI, Issue 13234, 4 March 1915, Page 3

SCIENCE AMI INVENTIONS

JIARD CONCRETE FLOOR SURFACE, Concrete floors in factories do not always stand tlio wear, so tliat tlio now fcrentmont now current should ltceomc' better known, A mixture of 15 tb or 20- lb of iron dust or ilour with 100 lb pf cement is added to twice tlmt much sand ami applied as a top coat, nearlyhn'ineh thick. "It is said to ho hard, very durable for heavy wear, waterproof, and not slippery. GOLD MINING IN MANITOBA. Manitoba is' rapidly coming to the front as a gold-produeing provineo. The first gold brick was recontly scut from n mine in tlio Rico Lake district. Its value was only £52, but it represented only .GO. per cent, of the actual value of a ton and n-half of ore, the remainder of lho metal still being on the plates of the mill awaiting the introduction ,of ■a cyanide plant before it could be secured. Gold Lake, from which this ore was taken, was discovered only three months ago. FLOOR-SCRUBBING MACHINES. •. A rotary electric Bci'ubbing machine, 'described 'in Hie Popular Mechanics' Magazine, has a capacity of from 5000 to 8000 square feet of lloor surface an hour, and is both rotated and propelled by electric.power. Power is supplied through an insulated wire, which may be attached to aiiv standard socket, and which is taken up and paid out as required by nn automatic reel carried on tho machine.' The water, which is

ixed"with a cleansing powder, is car

ricd in a ten-gallon tonic placed just above the rotary brushes of the scrubbing device.

A WATERPROOF CEMENT,

Tt is said thai the United Slates army engineers have long used the following mixture for water-proofing cement;One part of cement, two parts of sand, three-quarters of a pound of dry powdered alum to each cubic foot of sand. These are mixed and dried, and to them is added Water in which has been dissolved three-quarters of a pound of soap In each gallon. This, it is said, is nearly as strong as ordinary cement, and is. quite impervious to water, and does not effloresce. For a wash, a mixture of one pound of lye and Iwo ■pounds of alum in two gallons of water is often used. ORIENTAL WATER-BOTTLES. Hebron,, one of the oldest cities in Palestine, has always been famous for its Oriental water-bottles, made of goat skins. Here are to be found large tanneries whore these receptacles arc turned out by the thousand. Lying upon the ground in rows may be socii hundreds of goat skins awaiting purchasers. Each skin is 'inHatcd, either with water or with air, so that the buver may know it is perfectly watertight. The majority of the skins used come from Arabia, while a large number are also received from the Lebanons. They are brought to Hebron .by the camel caravans, and arc purchased, by the tanneries and turned, into bottles. They pass through many processes, and a tanner will spend a week upon a single skin before it is rendered wnter- y tight antl serviceable, From Hebron these old "bottles" are sent to all parts of the East, thousands going down into Egypt and the Soudan every, year. They are also used as rafts. A number of inflated skins are attached to a light wooden frame, which then not only readily floats, but is capablo of carrying quite a heavy load. Such craft are to be seen upon the rivers of Syrin, and also upon the Euphrates and Tigris.

TABLE SYRUP FROM APPLES. The head of the fruit and vegetable utilisation laboratory of .the U.S.A. Department of Agriculture has, il is reported, applied for a public service patent covering the making of a new form of table syrup from apple juice. By this patent, the result of extensive experiment's, ithe discovery, which the specialists believe will bo of great value fo all apple-growers as a means of utilising their culls and excess apples, will become the common property of any cider mill in the United States which wishes to manufacture and sell the product. The new syrup, one gallon of which is made from seven gallons of ordinary cider, is said to be of an attractive colour, and, sterilised and sealed, will keep indefinitely, and it is claimed will keep muler household conditions as well as oilier syrups.' Its flavour is described as similar to the taste of the syrupy substance which exudes from bilked apple, A cider mill in the Hood River Valley, Oregon, will this, fall undertake to manufacture mid test on the retail market 1000 gallons of concentrated eider, which will represent 5000 gallons of ordinary apple cider with only the water removed.

ELECTRIC MOTORS FOR PUMPING,

The use of electric motors.for. operating pumping plants is on the'increase in Europe. Nncli plants comprise city water works, sewage, and drainage planis, and we may consider two general classes of pumps', namely' piston and rotary pumps. Although the output of the rotary pump is much less than that of the piston pump, tho output of the highspeed electric motor which is usually coupled direct, on the rotary, pump'is greater than >lhnt of motors used with piston pumps, However, even with belt-drive on piston pumps, the nil-round yield is superior in this latter case. But tho rotary pump, has several advantages which lead to its use in a number of modern walcr-piimping plants, Pump 'and foundations cost but little, and the plant also is of small size. Upkeep is .small, for the bearings are almost always self-oiling. A recent compact group: has an electric motor and pump mounted on 'the some base, and such groups are most advantageous. Motors aro from'so to 100 Horse-power, and pumps can handle 1130 cubic'feet of water per miniitc. A good example of tliq use of, compact rotary pump groups is seen in tho largo Bangkok water-, works, which now uses five sets 'of this kind. An original plant is found at tho Coetlien waterworks, whevo tho source of supply is an underground well. Two electric.pump sets rire mounted directly in the bottom of the well shni't, a'udcau bo placed in this narrow space •without -n»y trouble. The' olectric motors nrobuilt with spocint insulation in.order tp, stand tho' dninpn'oss.