The discovery was soon utilized in Nobili's invention of the thermopile in which the current was increased by employing several layers of dissimilar metals (say antimony and bismuth) in series with each other.
The main use of the thermopile has been in scientific investigations, especially in the science of heat.
The measurements were chiefly of a qualitative character, and were made by interposing between the source and a thermopile a layer or plate of the substance to be examined.
But with the aid of the thermopile or other sensitive radiometer, they may be shown to belong equally to all the radiations from a heated body, even such as are thirty to fifty times slower in frequency than the longest visible rays.
If the eye should take the place of the thermopile it would be found that some of these rays did not affect it at all, while some would produce the sensation of light.
As the room-walls had pretty much a uniform temperature, the deflection of the galvanometer was but slight, when the tube-axis of the thermopile was directed anywhere outside of the hot-air current rising from the flame.
An ordinary lamp, with circular wick, and short glass cylinder, was wholly screened with a board, and a thermopile was so placed that its axis lay somewhat higher than the edge of the board.
Dubois (1886) first studied this problem in Pyrophorus by the use of a thermopile and galvanometer and found a small amount of radiation from the luminous region in excess of that from a non-luminous region.
When, however, the slit of the thermopile is placed beyond the limit of the visible spectrum, the deflection enormously increases, and will increase till a position is reached as far below the red as the yellow is above it.
That these dark rays possess greater energy or capacity for doing work of some kind than any other rays of the spectrum, can be shown by means of a linear thermopile (Fig.
The principle of the thermopile we need not describe in detail.
On the top of the mountain, at an elevation of ten thousand feet, he found that the moon's rays affected his thermopile to the same extent as a standard candle ten feet away.
Footnote 1: Probably most of our readers know that the thermopile consists of a number of little bars of two different metals, connected in pairs, and having the ends joined in a conducting circuit with a galvanometer.
We have no time or space here to describe Professor Langley's "bolometer;" it must suffice to say that it seems to stand to the thermopile much as that does to the thermometer.
The same author states that, "the earth is a great thermopile generating electric currents by the difference of potential between its heated and cooled parts.
A thermopile in the form of a circle with several pairs of metals, can easily be made by fastening the hairpins to a piece of cardboard (Fig.
The heat of a match, or the cold of a piece of ice, will produce a current even at some distance, the thermopile being connected with a sensitive short-coil astatic galvanometer.
The home-made thermopile described in ยง421; astatic galvanoscope; connecting wires; candle or alcohol lamp.
Gradually the light faded, as the thermopile adjusted itself to the change in temperature.
We call those junctions in a thermopile 'couples,' and by getting the recording instruments sensitive enough, we can measure one one-thousandth of a degree.
You see, down there I placed the couples of the thermopile beneath the electric furnace on the table.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "thermopile" in a variety of sentences. We hope that you will now be able to make sentences using this word.
