THE WORLD'S MOST POWERFUL TELESCOPE 

 By William H. Knight 



AT last the 100-incli mirror specially housed at the laboratory 

 of the Mount Wilson Observatory in Pasadena, was ready 

 to be packed and transported to its future home on the mountain 

 top, 17 miles distant, and 6000 feet above sea level. For four 

 years expert hands had been engaged in grinding and polishing 

 the great mirror and now it was daintily packed in thick cushions 

 to relieve any possible jar. It was then placed in an octagon 

 shaped box which was strongly reinforced by a crate of bolted 

 timbers and heavy iron rods. The whole mass, weighing nearly 

 seven and a half tons, was anchored edgewise upon a powerful 

 auto truck weighing five tons, and constructed expressly for this 

 journey. The wheels, seven feet apart, formed an ample base, 

 so that the top of the load, twelve feet from the ground, swayed 

 but little from the perpendicular. 



At 7 o'clock on the morning of July 1, 1917, the truck bear- 

 ing the world-famous mirror left the Pasadena laboratory amid 

 a throng of keenly interested spectators, and motored over the 

 mesa to the toll house at the foot of the mountain roadway, 

 where another crowd of 200 people were gathered to witness the 

 final ascent, and where thirty or forty automobiles lined the avenue. 



At the invitation of Mr. Francis G. Pease, who has been 

 doing notable work on the 60-inch refractor for several years, 

 and previously at the Yerkes Observatory, the writer occupied 

 a seat in his automobile which immediately followed the motor 

 truck bearing the precious burden. Mrs. Pease and Mars Baum- 

 gardt were the other passengers in our vehicle. Preceding the 

 main truck was another provided with cables and machinery 

 ready for use in case of emergency, but fortunately they were 

 not needed on the trip of nine and a half miles from the toll 

 house to the observatory building. The wonderful mountain road, 

 much of it forming a narrow shelf carved from the massive 

 granite rock, with many reentering curves and steep grades, was 

 traversed without a single mischance, and much credit is due 

 the skill and forethought of the Mack Motor Truck Company 

 for the entire success of the enterprise. 



The 100-inch mirror has an interesting history. To one man in 

 particular should be given large credit for the inception of the 

 idea. Mr. John D. Hooker, a prominent business man of Los 

 Angeles, was for several years vice president of the Southern 

 California Academy of Sciences, and he took such great interest 

 in the Astronomical Section that for ten years its meetings were 

 held in a hall of his private residence on Adams street. 



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