SCIENCE AND INDUSTRY. 
SUBSTITUTES FOR LEATHER BELTING. 
Owing to the shortage of raw materials necessary for manufacturing 
driving belts in 1916, the Belting Control Department of the Imperial 
Ministry of Economics was formed in Berlin to take over the control 
of the manufacture and use of driving belts. A great deal of valuable 
research work was carried out under the control of the Department, 
and much useful information hitherto unknown regarding the efficiency 
of substitutes for leather belting has recently been made available. The 
field of substitute can be generally divided into two parts :— 
1. Belts manufactured on the principle of textile belting; that 
is, from woven flat webbing, strapping, or rope of hemp, paper, 
&e., with or without the use of interwoven wire. 
2. Belts of the leather link type, manufactured from individual 
links of wire, wood, compressed paper, or sheet metal. 
To the first class of belts we may reckon the cellulose belts and 
belts of mixed material. Cellulose belts are manufactured with thread 
made from sodium sulphite paper. The strength of these depends 
upon their form and method of construction. The main forms 
are: Folded (like cotton belts), built up from several separate ropes or 
tubes, woven and knitted belts, twine belts, and wire-armoured belts, 
mostly impregnated against the influence of moisture. Mixed material 
belts are in general differentiated from cellulose belts by the introduc- 
tion of vegetable fibres or threads into their composition, either before 
or during the spinning process, or before they are woven into belting. 
Besides assuming the above-mentioned forms, these belts are also often 
plaited. 
The most important of the second class are made of wood, compressed 
paper, or wire links. Belts composed of links of wood or compressed 
paper are manufactured by pressing together laminations of the material 
in the manner used in the Gall chain. In ‘order to: increase their 
strength, the individual laminations are frequently held together by 
means of metal clips, which, however, are arranged in such a way that 
only the wood or compressed paper comes into touch with the belt 
pulley. Belts of wire links are manufactured by placing side by side 
flattened wire coils, and fastening them together by means of bolts. In 
order to increase the adhesion of the belt to the pulley, paper twine is 
wrapped between the coils. : : 
The idea that now the war is over there will be no need to use belts 
of substitute materials rests on a misunderstanding of the still existing 
difficulties of meeting the total demand for driving belts. 
RESEARCH ON NON-METALLIC MINERALS. 
In the Engineering and Mining Journal, New York, attention is 
drawn to the fact that in the past the non-metallic minerals have been 
considered as of minor importance in the mining industry. With the 
exception of such substances as phosphate rock, limestone, dolomite, and 
recently, magnesite, attention has been concentrated largely upon the 
metallic minerals. In recent times, we have seen the development of 
the alloy steels, with the resulting benefit to the structural engineer, 
and to manufacturers of high-speed engine and tool steels.. Tungsten 
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