Popular Science Monthly 



Incandescent Lamps May Now Be 

 Used to Project Motion Pictures 



IT has always been more or less difficult to 

 give motion pictures in places other than 

 a regular theater equipped for the purpose. 

 A lamp has been devised recently which will 

 make motion pictures possible in 

 churches, schools and even in 

 the home. There is nothing 

 which equals motion pictures as 

 a means of popular enter- 

 tainment. Many a small 

 fair, held for charity, would 

 be more successful from a 

 financial point of view if the 

 added attraction of lively 

 motion pictures could be 

 offered. 



A low voltage con- 

 centrated filament 

 lamp has been de- 

 veloped which may 

 be used with a new 

 lamphouse designed 

 especially for motion 

 picture use. The 

 lamphouse contains 

 a double lamp holder 

 with several adjust- 

 ments, a reflector and 

 two sets of condens- 

 ers, one for stereopticon and the other for 

 motion picture use. 



A compensator with ammeter and resist- 

 ance regulator is used for alternating cur- 

 rent and a small rotary converter for direct 

 current. Where the amount of electricity 

 consumed is not important a specially 

 designed resistance with ammeter may be 

 used on direct current. 



All conditions which might make op- 

 eration difficult 

 may be met 

 by the use of 

 this lamp and 

 lamphouse. A 

 twelve-foot pic- 

 ture has been 

 shown success- 

 fully at one hun- 

 dred feet. The 

 apparatus may 

 be used, how- 

 ever, to project 

 small pictures 

 such as would be 

 suitable for an 

 entertainment to 

 be given at home. 



Switch 

 Details of the low voltage concentrated fila- 

 ment lamp and lamphouse for motion pictures 



893 



The War Gardens of Railroad Em- 

 ployees and Station Agents 



STATION agents of many railroad com- 

 panies have become war gardeners this 

 year. There are one thousand two hun- 

 dred such war gardens on the vacant lands 

 of the Pennsylvania Railroad. It is ex- 

 pected that the value of the crops raised in 

 these gardens will be two hundred and 

 fifty thousand dollars. 



The crops tilled by the rail- 

 road employees aver- 

 age a little less than an 

 acre. They are planted 

 with potatoes, peas, 

 beans, tomatoes, corn, 

 and various other 

 vegetables. 



An agent on the 

 New York Central, 

 stationed at Chau- 

 mont, New York, 

 has specialized in 

 beans. He planted 

 a plot one thousand 

 five hundred feet 

 long and twenty-five 

 feet wide on the off- 

 side of the station 

 platform. 



How a tug was raised out of the water by the 

 dredge and held until the propeller shaft was repaired 



A Dipper Dredge That Served as a 

 Temporary Dry Dock 



THE propeller of a tug on the Black 

 River was injured. It was necessary 

 to straighten the propeller shaft. But the 

 owners did not want to put the tug in dry 

 dock. So the dipper of a dredge was 

 lowered on to the stern of the tug. Then a 

 cable was passed around the hull of the tug 

 and fastened to 

 the [dipper. 

 When the dipper 

 was raised the 

 stern of the tug 

 was lifted Gut of 

 the water to al- 

 low the propeller 

 shaft to be taken 

 out. The shaft 

 was straightened 

 and replaced in 

 much less time 

 than if the tug 

 had been put 

 into dry dock 

 and with no 

 inconvenience. 



