TEE WORLD'S ADVANCE 



67 



It is operated from the keyboard of a 

 standard machine located on a desk a few 

 feet in front. The keys of the two ma- 

 chines are connected electrically and the 

 motive power for the larger is obtained 

 from electric motors. The operation of 

 typing is necessarily slow, but the ma- 

 chine serves admirably for attracting the 

 attention of visitors. 



One of the features attracting consid- 

 erable attention at The American Pulley 

 Company's exhibit in the Palace of Ma- 

 chinery is the demonstration which 

 shows the perfect balance of all "Ameri- 

 can" pulleys. A large 72-inch diameter 

 by 36-inch face, triple arm, steel split 

 pulley, weighing approximately 1,500 

 pounds, is turned with perfect ease by a 

 thread of the finest silk. The pulley is 

 in such perfect balance that no starting 

 other than that of the motor is necessary 

 to put it in motion. In other words, the 

 silk thread is capable of taking care of 

 the starting load. A new device called 

 an "Efficiency Indicator/' measuring ac- 

 curately to 3-1000 of a h.p., shows the 

 exact amount of horsepower required to 

 revolve any pulley. 



The U. S. Weather Bureau maintains 

 an instructive exhibit in the Palace of 

 Agriculture. The first instrument of in- 

 terest is a seismograph, used for record- 

 ing the undulatory motions, duration and 

 direction of an earthquake. It consists 

 essentially of a horizontal arm several 

 feet in length, attached to a vertical up- 

 right in such a manner that it is free to 

 oscillate in a horizontal plane. A heavy 

 mass is placed at the outer extremity of 

 the arm to damp the vibrations. The 

 magnitude of oscillation is magnified by 

 a mechanical system of levers and the 

 seismic tremors are recorded by a pen 

 on a slowly revolving sheet of paper trav- 

 eling at right angles to the direction of 

 oscillation. The vibration of the floor, 

 due to a person approaching the instru- 

 ment, causes the recorder to move 

 through an arc of several inches. 



The next instrument, a pyrheliometer, 

 is used to determine the amount of in- 

 solation or radiant energy received from 

 the sun at place of exposure. A cloud 

 nephoscope is of interest in that it meas- 

 ures the azimuth, angular velocity, di- 



rection of motion and apparent velocity 

 of motion of the cloud under observa 

 tion. 



A kite meteorograph is used for re- 

 cording four conditions of the atmo- 

 sphere. One pen actuated electrically by 

 the kite anemometer traces a record of 

 the velocity of the wind, a second pen 

 traces a record of the temperature of 

 the air, and a third pen traces a record 

 of the percentage of moisture in the air. 

 The meteorological balloon tugging away 

 at the floor is also of interest. It is 

 about four feet in diameter and carries 

 a small wicker-work basket in which is 

 placed the balloon meteorograph. This 

 instrument has recorded a temperature 

 of minus 92 degrees F., an altitude of 20 

 miles and a horizontal distance of over 

 260 miles. 



A snow sampling tube and weighing 

 scales are used for determining the water 

 contents of a snow layer and the ap- 

 proximate number of acre-feet of water 

 in the form of snow on any water shed. 

 The weekly floating rain gauge makes 

 an automatic record of the beginning-, 

 ending, rate and amount of every shower 

 of rain during the period of a week and 

 requires attention but once in such 

 period. 



Other instruments shown are anemo- 

 meters, for measuring the velocity of the 

 wind; airmeters, for measuring drafts; 

 psychrometers, for measuring moisture; 

 hygrographs, which write the relative 

 humidity for the week; barographs, for 

 recording air pressure; and thermo- 

 graphs, maximum and minimum ther- 

 mometers, aneroid and siphon barome- 

 ters, evaporimeters, rain gauges, snow 

 stakes, river stage indicators and weather 

 charts. 



The smallest electric motor and steam 

 engine in the world are on display in the 

 North Dakota state building. They are 

 the work of Mr. Ivan T. Nedland of that 

 state and documentary proof is given as 

 to their actual working ability. The mo- 

 tor runs by the current from a dry cell, 

 while the engine is operated by com- 

 pressed air. 



If you enjoy THE WORLD'S ADVANCE, 

 tell others; if not, tell us. 



