The Locomotive - Lighthouse Survival Blog

156 THE LOCOMOTIVE. [October
HARTFORD, OCTOBER 15, 1894.
J. M. Allen, Editor. A. D. Risteen, Associate Editor,
The Locomotive can be obtained free by calling at any of the company's agencies.
Subscription price 50 cents per year when mailed from this office.
Bound volumes one dollar each. (Any volume can be supplied.)
Papers that borrow cuts from us will do us a favor if they will mark them plainly in returning,
so that we may give proper credit on our books.
By an unfortunate clerical error, the total number of dangerous defects found by
our inspectors during the month of July was stated (in our September issue) to have
been 1,097. It should have been 1,102, as an addition of the column in question will
show.
The following data concerning the steam power of the world are quoted by our
esteemed contemporary, the Safety Valve. They are said to have been given out by
the bureau of statistics in Berlin: Of the steam engines now working, four-fifths have
been constructed during the last twenty-five years. France has 49,590 stationary and
locomotive boilers, 1,850 boat boilers, and 7,000 locomotives: Germany, 59,000 land
boilers, 1,700 ship boilers, and 10,000 locomotives: Austria, 12,000 boilers and 2,800
locomotives. The working steam engines of the United States represent 7,500,000
horse-power; Germany, 4,500,000 horse-power: France, 3,000,000; Austria, 1,500,000.
This estimate does not include the locomotives, wdiose number in the world is 105,000.
representing a total of 3,000,000 horse-power. The world's steam engines, therefore,
aggregate more than 26,000,000 horse-power, equivalent approximately to the work of
1,000,000,000 men.
What is a Heat Unit?
When, in ordinary conversation, a person uses the word "heat." there is often some
uncertainty about the precise meaning that he intends to convey by it. This uncer-
tainty arises partly from the many figurative meanings of the word, but principally
from a confusion of "heat, 1
' properly so-called, with "temperature.''' For example, we
speak of the "heat of the day," meaning that part of it which is hot — i. e., the middle
of the day. Again, we speak of the " heat of a furnace,"— meaning, really, the temperature
of the furnace. In the expression " animal heat," on the other hand, the word
" heat" is possibly used in its strict sense, and we understand it to mean a quantity of
some sort or other, which could be measured just as definitely as wood or potatoes can
be, if we could only devise some appropriate unit by wdiich to perform the measurement.
In order to get a somewhat clearer idea of the difference between heat and temper-
ature, let us consider a tub of hot water. A thermometer immersed in this water reads
(say) 200° Fah. : and under these circunstances many persons w r ould say that the water
"contains 200 degrees of heat." Now nothing could be more misleading nor more
erroneous than such a statement as that. It should be observed that the only thing we
have determined is the temperature of the water; and the thermometer would read just