SCIENCE AND INDUSTRY. 
hence the price of sulphate of ammonia rose to £22 (1880) and eyen to. 
£24 per ton; but as the importation of nitrate of soda increased 
greatly, it fell below £8 per ton about 1890, when burning oil sold at 
less than 6d. per gal. ‘These conditions led to further concentration. 
Retorts especially designed for the manufacture of sulphate of ammonia 
were universally adopted, and improvements were introduced to secure 
greater economy of working. With the older type of retorts a shale 
had to yield about 30 gals. of crude oil per ton in order to be profitable: 
but with the new retorts and the increased yield of ammonia and fuel 
gas a shale furnishing 20 gals. is remunerative. Not more than 16 Jb. 
of sulphate of ammonia per ton was formerly obtained as a maximum, 
now 35 to 70 lbs. is got, according to the quality of the shale. By 
these methods the quality of shale that can be worked with profit has 
been increased and the life of the Scottish industry has been lengthened. 
“ Since 1873 the Russian petroleum industry has developed rapidly, 
and in recent years competition from this source has become very severe. 
Russian crude oil, however, produces no solid paraffin; and America 
shows signs of not being able to respond as easily as formerly to the 
increased demands of the world for petroleum, any increase in Ameri- 
can output being fuel oil. In 1905, however, it succeeded by great 
effort in making up for the Russian deficiency caused by troubles at 
Baku. In 1909 and 1910 there was a definite decrease in the export 
of burning oil from America to Britain. Sulphate of ammonia is 
being produced in greater quantities from iron works, coke ovens, 
Mond gas producers, &c.; but the demand also increases. New com- 
petitors are always arising; recently, for instance, Galicia with solid 
paraffin, Rumania with burning oil, and the Dutch East Indies with 
motor spirit, But notwithstanding this prolonged and fierce struggle 
for existence, the Scottish industry still survives. The Scottish com- 
panies vie with one another in their efforts to improve and cheapen 
the processes, and show signs of mutual helpfulness and co-operation. 
In the early days of the industry operations were carried on in a simple 
but expensive fashion. Sometimes the shale was carted miles to the 
retorts, and the crude oil carted miles to the refinery, and breaking 
shale, pumping oil, &e., were done by manual labour. But through all 
these years evolution has been at work in developing a high’ state of 
organization, resulting in economy and efficiency. The most of the 
existing works have adopted electricity for lighting and for the con- 
veyance of power for all purposes. , 
“Tn 1894 there were thirteen oil companies in Scotland; now there 
are only seven (three of which produce crude oil only), but the output 
has not been reduced.”* asa 
New anp Improvep Pracricr Berne Drvetoren. 
Thus there is seen fhe continual application of new and. improved 
practice in the Scotch industry, a practical seeking after better methods, 
perhaps not by means of strictly scientific research, but nevertheless 
by research, which; conducted in a practical manner and with a definite 
object in view, has kept. the industry alive. It may be noted that the 
* The largest of these consolidated into one company, Scottish Oils Ltd., im 1919.A yrnok, + 
758 
