A "good eater," however,
may require as many as thirty.
An Australian Railway Viaduct.--The Werribee Viaduct, in the colony of
Victoria, is the longest work of the kind in Australia. The structure
consists of lattice-girder work. It is 1,290 feet in length, and runs
to a height of 125 feet above the level of the Werribee river. The
viaduct has fifteen spans each of 60 feet, and thirteen spans of 30
feet. The total cost of the bridge was L600,000.
The Sharpening of
Tools.--Instead of oil, which thickens and smears the stone, a
mixture of glycerine and spirit is recommended. The proportions of the
composition vary according to the class of tool to be sharpened. One
with a relatively large surface is best sharpened with a clear fluid,
three parts of glycerine being mixed with one part of spirit. A graver
having a small cutting surface only requires a small pressure on the
stone, and in such cases the glycerine should be mixed with only two
or three drops of spirit.
Recipes for Plumbers.--Chloride of zinc, so much used in soldering iron,
has, besides its corrosive qualities, the drawback of being unwholesome
when used for soldering the iron tins employed to can fruit, vegetables
and other foods. A soldering mixture has been found which is free from
these defects. It is made by mixing one pound of lactic acid with one
pound of glycerine and eight pounds of water. A wooden tank may be
rendered capable of withstanding the effects of nitric or sulphuric
acids by the following methods:--Cover the inside with paraffin; go over
the inside with a sadiron heated to the temperature used in ironing
clothes.
Pages:
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559