April 10, 1908] 



SCIENCE 



577 



to make the contracts and attend to other 

 necessary details. Bids from four inde- 

 pendent firms of contractors were submit- 

 ted early in May, and on May 14, 1907, 

 a contract was entered into with Messrs. 

 Horton and Hemenway to do the work of 

 construction for $68,334, and a similar 

 contract was made with Messrs. Buerkel 

 and Company, of Boston, to supply the 

 heating and ventilating apparatus at a cost 

 of $14,825. These contracts required that 

 the building be completed by February 1, 

 1908. The construction was begun early 

 in July and the building is now rapidly 

 approaching completion. 



Through the courtesy of the authorities 

 of the Harvard Corporation, the laboratory 

 will be able to secure heat, light, power and 

 refrigeration, at the cost of production, 

 from the near-by power house of the Har- 

 vard Medical School. The site of the labo- 

 ratory is also near to existing and contem- 

 plated hospitals, and the location appears 

 to be in every way extremely favorable for 

 the prosecution of the arduous researches 

 required to improve our knowledge of the 

 physics, chemistry and pathology of nu- 

 trition. 



THE SOLAR OBSERVATORY 



The work of this department is still 

 largely in the preparatory stage, and is 

 thus as much a work of engineering as of 

 astronomy. The novelties of construction, 

 equipment and program of research for the 

 observatory, along with the initial difficul- 

 ties presented by a moiintain site, conspire 

 to make the undertaking a formidable one. 

 In spite of many obstacles, due chiefly to 

 unprecedented precipitation during the 

 past winter and to labor troubles on the 

 Pacific coast, the work of construction has 

 gone rapidly forward. 



The optical parts of the 60-inch reflect- 

 ing telescope have been made ready for 

 mounting, but owing to the labor strikes 



at San Francisco the completion of the 

 dome for the telescope may delay its erec- 

 tion until the spring of 1908. 



The novel tower telescopic apparatus, 

 part of which is above and part of which 

 is below the ground level, has been sub- 

 stantially completed. This consists essen- 

 tially of a vertical telescope with a 12-inch 

 objective and 60 feet focal length in com- 

 bination with a Littrow grating spectro- 

 graph of 30 feet focal length, thus fur- 

 nishing a powerfitl component in the bat- 

 tery of instruments for direct observations 

 of the sun. 



Preparations for grinding, figuring and 

 testing the 100-inch reflector, whose con- 

 struction, as explained in my preceding 

 report, was rendered possible by the gift 

 of Mr. J. D. Hooker, have likewise gone 

 forward. A fire-proof building for this 

 work has been constructed and the neces- 

 sary grinding-machine is nearing comple- 

 tion. In the meantime it is expected that 

 the Plate Glass Company of St. Gobain, 

 France, will soon have the large disk for 

 this reflector ready for shipment, since it 

 was successfully cast on August 28 last. 

 In the rough this disk will weigh about 

 4.5 tons. 



Simultaneously with these varied works 

 of construction, daily photoheliographie 

 and spectroheliographic observations have 

 been made by aid of the Snow telescope. 

 Daily studies of the sun and sun-spot spec- 

 tra have supplemented these observations, 

 and to them have been added pyrhelio- 

 metric and solar magnetic measurements, 

 along with numerous laboratory investiga- 

 tions bearing directly on the physical prop- 

 erties of the sun. 



DEPARTMENT OP TERRESTRIAL MAGNETISM 



The year for this department has been 

 one of varied activities and one specially 

 fruitful in the quantity and quality of the 

 results attained. The operations have em- 



