74 



Gliding Boat for Tropical River 

 Mail Service 



A GLIDING boat that speeds over 

 the water at the rate of fifty miles 

 an hour has been built for transporting 

 mails on the Magdalena river in Colum- 

 bia, between the Carribean coast and the 

 capital city, Bogota, a distance of six 

 hundred miles. On her trial trip, from 

 the factories at Nyack, N. Y., to the foot 

 of Ninety-first Street, New York, a dis- 

 tance of twenty-two miles, the "Yolanda 

 11" covered the distance in less than a 

 half hour. 



Popular Science Monthly 



The Steam Engine in War 



THAT the Lanz locomobile, the 

 name by which a remarkable port- 

 able superheated steam engine is known, 

 is equally as successful for war as well 

 as peace purposes is convincingly shown 

 by its behavior during the past year on 

 the various battle fronts. 



One of the most interesting applica- 

 tions of the locomobile is for power pur- 

 jx)ses in connection with field equipment, 

 such as wireless telegraph sets. One lo- 

 comobile is supplying energy to a two 

 hundred horsepower field wireless equip- 



This gliding boat, which takes its power from the displacement of air instead of water 



by its propellers, was built in New York for use on a tropical river, where weeds make the 



use of screw propellers in the water impossible 



Two gasoline engines of one hundred 

 and fifty horsepower each are connected 

 to an air propeller. It is impossible to 

 use screw propellers in the Magdalena, 

 as the sea weeds and grass are so thick. 



The Yolanda II draws three inches of 

 water while speeding at a rate of fifty 

 miles an hour, and five inches while at 

 rest. She was designed by Gonzalo Mejia, 

 an engineer of Columbia. The prob- 

 lem of transportation on tropical rivers, 

 where the shallow draft of encumbering 

 sea weed, makes a draft of more than 

 a few inches impracticable, has engaged 

 the attention of native engineers for 

 years. Mr. Mejia's boat is one of the 

 best devices yet built to meet the prob- 

 lem. 



ment. The locomobile is used extensive- 

 ly in operating pumps directly behind 

 the firing line. A more extensive use 

 is in supplementing the power plants of 

 ammunition factories. 



In one plant two locomobile units of 

 five hundred horsepower each were add- 

 ed ; in another, which, before the com- 

 mandeering of the fuel oil supply, had 

 been employing oil engines, a single one 

 hundred and twenty horsepower locomo- 

 bile engine supplanted the entire power 

 equipment. 



Among other applications of the loco- 

 mobile are hauling gims and ammunition 

 trains to the various batteries, and in 

 heating hosj^itals and prison camps with 

 ihe hot water from its boilers. 



