Intermezzo
(-met'zō), in music, an interlude; a short composition of a lively character played between the parts of a more important work, or between the acts of a drama, etc.
INTERMITTENT AGUE.
FEVER. See INTERNAL COMBUSTION EN- GINE, a type of prime mover in which the actuating energy, in the form of heat, is generated by combustion within the cylinder of the engine.
The commercial introduction and improvements of the internal combustion INTERNAL COMBUSTION ENGINE 171 INTERNAL COMBUSTION ENGINE engine have been comparatively recent, as it was only in 1878 that Otto placed the first important commercial gas engines upon the market. In his engine, as in the common motor of to-day, the gas was compressed before it was ignited.
The two great classes into which internal combustion engines may be divided are: on of done at approximately the end of the compression; fourth, the expansion which forces the piston down; and fifth and last, forcing out the burnt gases on the up stroke of the piston. This type the gas, resulting from combustion, the piston to complete its cycle, is known as a four-cycle motor, while some motors of motor, which requires four strokes of with special valve arrangements and EXHAUST VALVE EXHAUST PISTON CYLINDER HEAD RINGS WRIST PIN CYLINDER SHAFT SHAFT CRANK CASE SPARK PLUG VALVE HEAD INLET VALVE INLET FOR FUEL MIXTURE VALVE SPRING VALVE ROD PISTON CAM CAM SHAFT C TIMING GEAR FRAME CRANK SHAFT CROSS SECTION OF FOUR-STROKE GASOLINE INTERNAL COMBUSTION ENGINE CRANK SHAFT A. Those in which the ignition of the fuel occurs at constant volume. A. Those in which the ignition of B. Those in which the ignition of the fuel occurs at constant pressure.
The common gasoline motor of today is of the first type, and usually opday is of the first type, and usually opcycle: first, charging the cylinder with fuel, which is done on a down stroke of cycle: first, charging the cylinder with the fuel on the up stroke of the piston; deflectors go through a complete cycle in two strokes. designed to operate on natural gas, al- Gasoline is the common fuel of this with air in a carburetor or similar detype of motor, although there are models vice. The entrance of the fuel into the cylinder, as well as the expulsion of burnt gases, is controlled by valves, which may be of the poppet an cylinder, as well as the expulsion of vice. The entrance of the fuel into the with air in a carburetor or similar deand cam VALVE CLOSED EXHAUST SPARK PLUG "INLET VALVE OPEN CYLINDER PISTON SUCTION STROKE COMPRESSION STROKE POWER STROKE EXHAUST STROKE SCHEMATIC DIAGRAM SHOWING HOW A FOUR-STROKE CYCLE SINGLE-CYLINDER INTERNAL COMBUSTION ENGINE WORKS 500 pounds per square inch, which creates a temperature of about 1000° F., then at the beginning of the down stroke of the motor, oil under high pressure is sprayed into the cylinder, where it is ignited by the heat of the air in the cylinder. A constant pressure is maintained during expansion. On the up stroke of the piston the burnt gases are expelled from the cylinder, and the cycle is repeated. This type of engine is practical only in large sizes, and is used for stationary power plants, and for heavy marine duty. It may be either vertical or horizontal, and recent experimentation has improved the speed control and simplified starting, which were the drawbacks of early models. A very high fuel ment has erected a handsome building for its home. A general assembly of delegates is held every two years and over 40 different countries are now represented in its deliberations. In 1913 the assembly discussed methods of crop reporting, an international service of statistics, and made proposals to the departments of agriculture of the various nations concerning concerning the control of plant diseases. The institute has collected a valuable library dealing with all phases of agricultural life, issuing weekly bulletins of books received or published on the subject. It has also aided the various countries in any special agricultural works in which it happens to be engaged, recommending experts and INTERNAL COMBUSTION ENGINE 172 INTERNATIONAL INSTITUTE modern motor the fuel is ignited by an ' economy is possible with this type of electric spark, properly timed, which is usually furnished by a storage battery and intensified by a coil, or generated by a magneto. The lubricating system is usually either of the force feed or the splash type, and a great majority of the engines are water jacketed for cooling.
This type of motor is used for motor vehicles of all types, for small power plants, airplanes, and motor boats.
The typical internal combustion engine of the second type is the Diesel Engine, invented by a German, Rudolf Diesel, in 1898. In the Diesel Engine air is drawn into the cylinder, compressed to about motor.
INTERNATIONAL INSTITUTE OF AGRICULTURE, an institution located at Rome and having for its object the collecting and distributing of information and statistics about Agriculture. Founded by an American, David Lubin of California, who, after several vain attempts to secure government support, persuaded King Victor Emmanuel of Italy to give it his patronage in 1905.
The King has endowed the institution with funds which give it an annual income of $60,000 and the Italian Govern- EXHAUST VALVE <← CLOSED SPARK TAKES PLACE NOW INLET VALVE CLOSED EXHAUST VALVE CLOSED INLET VALVE CLOSED VALVE OPEN EXHAUST INLET VALVE CLOSED INTERNATIONAL LANGUAGES 173 INTERNATIONAL LANGUAGES, library.
INTERNATIONAL languages artificially formed in order to LANGUAGES, do away with the difficulties of communication between people whose natural languages are different. Most of is no aim to produce a literature in a help business men and travelers, there is no aim to produce a literature in a language artificially formed. Early attempts to make an international language date back to Diderot and the French Revolution, but perhaps the most famous of them are Volapük, Bolak or the Blue Language and Esperanto. The larity, but the fact that it copied Eng- in 1879 and attained considerable popularity, but the fact that it copied English too closely aroused the opposition of the Continent. The second, Bolak, was Paris who devoted a lifetime to the task the subject. The difficulty with the Blue Language as it is called is that it is a foreign language and consequently has proved of little practical value. Esperin vogue at the present time, its great advantage being that it makes consideradvantage being that it makes considerates what is special and irregular in eat ates what is special and irregular in the various languages, and retains that which is regular. Thus Esperanto is the easiest to acquire of any of these artificially formed languages. Americans have since proposed two other international languages, Ro by Foster (1910), and Pangerman by Molee (1911).
INTERNAL REVENUE earlier. As early as 1806 the improvement of roads by the National Government was conceived in order to indemican (Democratic- Jefferson, purposes. The Whigs improvement by the National Governimprovement by the National Governbegun. The Republican ment directly of rivers and harbors was Madison, and Monroe, opposed these im- Republican) Presidents, toward the end of his term Monroe betoward the end of his term Monroe became more favorable to the system. John Quincy Adams was a warm advocate thereof and Jackson its stern opany general system of improvements, ponent. The Though the Democrats opposed ticular adopted the system originated by the they continued to apply funds to par- ticular purposes. The Whigs now Democrat, Jackson, viz., the distribution of the surplus among the States. But once did the Whigs attempt to put this into execution, and then, in 1841, the that scheme, which has not since been veto of President Tyler, revived. The introduction of railroads his party in Congress, put an end to veto of President Tyler, at odds with an end to er, at odds with of improvements for roads, while a system of assistance to the railroads, by has partly done away with the question revived. The introduction of railroads means of the grant of land along the line of their route, has sprung up. and the present tendency is to the reand the present tendency is to the reas has not been earned by a strict comas has not been earned by a strict comthis both of the great political parties pliance with the terms of the grant. To stand committed.