Decembeb 12, 1919] 



SCIENCE 



531 



thrift and justified by tlie widely prevalent 

 but immoral theory that the institution may 

 proceed " regardless of expense." 



THE HOOKER TELESCOPE 



One of the distinct, if relatively unim.- 

 portant, misfortunes of the world war was the 

 delay in testing the capacities of the 100-inch 

 telescope named after Mr. John D. Hooker, 

 of Los Angeles, who made the initial contri- 

 bution toward the construction of this in- 

 strument thirteen years ago. It was sub- 

 stantially (3ompIeted shortly before the United 

 States became a participant in the conflict. 

 About this time, also, the director of the Ob- 

 servatory became chairman of the National 

 Research Council and he continued to give all 

 his time to this governmental organization 

 until May of this year. In the meantime, 

 likewise, as already indicated, the staff of the 

 observatory was preoccupied largely with 

 military rather than with astronomical affairs. 

 Hence, opportunity has only recently arrived 

 for determination of the critical question 

 whether this "largest telescope," which is 28 

 inches larger than its largest predecessor, and 

 40 inches larger than the highly successful 60- 

 inch instrument completed by the observatory 

 in 1908, would meet expectations in optical 

 capacity and practicability of operation. The 

 construction of so large a telescope has been 

 regarded as one of the hazardous undertakings 

 of the institution. Its optical perfection de- 

 pends on the stability of the glass used for 

 its mirror; the stability of the latter depends 

 in turn on the rigidity of its mountings; the 

 requisites in both cases must take into ac- 

 count the elastic mobility of materials and 

 the disturbing effects on them of temperature 

 changes; and all these considerations must 

 unite to secure a combination which is man- 

 ageable. The problems in engineering thus 

 presented have appealed very strongly to all 

 parties interested in such constructions, per- 

 haps almost as strongly as the astronomical 

 possibilities anticipated from such an exten- 

 sive addition to visual apparatus. But the 

 director of the observatory now reports that 

 the optical and the engineering difBculties 



have been overcome and that the instrument 

 under repeated tests has proved efficient quite 

 beyond the conservative theoretical predictions 

 of attainable capacities. 



THE NON-MAGNETIC SHIP 



As related in the report of the preceding 

 year, it was deemed expedient, in April, 1917, 

 on account of dangers to navigation, to 

 suspend the cruise contemplated by the De- 

 partment of Terrestrial Magnetism for addi- 

 tional surveys in the Atlantic Ocean by the 

 ship Carnegie. As related also in that report, 

 this ship was brought safely, by way of the 

 Pacific Ocean and the Panama Canal, to the 

 port of Washington, District of Columbia, 

 arriving there Jime 10, 1918. She lay here 

 until the spring of 1919, when it was decided 

 to send her out again on her mission as soon 

 as necessary repairs and alterations could be 

 made. Of the alterations required, the most 

 important was the adaptation of her engine 

 for auxiliary propulsion to the use of gasolene 

 as fuel. When the ship was launched, in 

 1909, it was easier to get anthracite coal than 

 gasolene or other liquid fuel in remote parts 

 of the world. Hence the engine was con- 

 structed to use gas derived from such coal by 

 the so-called producer process. In the mean- 

 time, anthracite coal has become much less 

 and gasolene much more accessible at distant 

 seaports, and this circumstance has led to the 

 noteworthy, and in these times expensive, but 

 highly advantageous change here specially re- 

 ferred to. After delays which serve to em- 

 phasize the inefficiency of mankind under 

 post-war conditions, on October 19, the Car- 

 negie, under the command of Mr. J. P. Ault, 

 put to sea from the Virginia Capes, on her 

 sixth cruise, to comprise surveys in the At- 

 lantic and Indian Oceans not yet adequately 

 covered by previous circuits. 



PUBLICATIONS OF THE YEAR 



Of all branches of the institution the one 

 least affected by the war is the Division of 

 Publications. Although it has undergone 

 some changes in staff and encountered the ob- 

 stacles due to a rapid rise in the costs of 

 printing and illustrations, its work has gone 



