Scientific American Supplement, No. 470, January 3, 1885Various
Science
Scientific American Supplement, No. 470, January 3, 1885
Various
Science -- Periodicals
The inventor claims that, as his engine works the steam expansively, even
better results would have been obtained had the engine been furnished
steam at 100 pounds per square inch.
[Illustration: Figs. 2 and 3.--DETAILS OF HARRINGTON ENGINE.]
The Harrington Rotary Engine Company, 123 Clinton Street, Chicago, are the
owners and manufacturers.
* * * * *
In a can of peas sold in Liverpool recently the public analyst found two
grains of crystallized sulphate of copper, a quantity sufficient to
injuriously affect human health. The defendant urged that the public
insisted upon having green peas; and that artificial means had to be
resorted to to secure the required color.
* * * * *
TESTING CAR VARNISHES.
By D.D. ROBERTSON.
At the Master Car-Painters' Convention, D.D. Robertson, of the Michigan
Central, read the following paper on the best method of testing varnishes
to secure the most satisfactory results as to their durability, giving
practical suggestions as to the time a car may safely remain in the
service before being taken in for revarnishing:
The subject which the association has assigned to me for this convention
has always been regarded as important. There is no branch of the business
which gives the painter more anxiety than the varnishing department. It is
more susceptible to an endless variety of difficulties, and therefore
needs more close and careful attention, than all other branches put
together, and even with all the research and practical experience which
has been given to the subject we are yet far from coming to a definite
conclusion as to the causes of many of the unfavorable results.
Beauty and durability are what we aim at in the paint shop, and from my
experience in varnish work we may have beauty without durability, but we
have rarely durability without beauty, so that the fewer defects of any
kind in our work caused by inferior material, inferior workmanship, or any
other cause, it is more likely to be durable, and ought, therefore, to
possess beauty. There are certain qualifications absolutely necessary to
durability in varnish. The material of which it is made must be of the
proper kind, pure and unadulterated; the manipulation in manufacturing
must be correct as to time, quantities, temperature, handling, etc., and
age is also necessary. The want of durability arising from the quality of
the materials, or from the manner of manufacturing, the painter has no
control over; but let me say here, that frequently a first-class varnish
has been used upon a car, and after being in service for a short time it
deadens, checks, cracks, chips, or flakes, and therefore shows a very poor
record. The varnish is condemned, when in reality, had the varnish been
applied under different circumstances and over different work, the result
would have been good and the durability satisfactory.
Public-domain text, read in full here on John Shaqi.
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