296 CARNEGIE INSTITUTION OF WASHINGTON. 



(5) The one-quarter-chain fire-break around the site has been plowed over, 

 as also a fire-break around a 15 by 25-chain area surrounding the observatory- 

 buildings. 



(6) The furnishing of the observers' quarters was completed. 



(7) An addition to the observers' quarters, in accordance with the detailed 

 plan supplied by the office, to provide a separate apartment for the assistant 

 observer, was partly completed. 



During the Carnegie's call at Fremantle the land instruments on 

 board were taken to Watheroo and complete intercomparisons with the 

 observatory instruments were obtained. 



Mr. W. C. Parkinson has been chief assistant throughout the year. 



HUANCAYO MAGNETIC OBSERVATORY. 



Despite untoward conditions and an unusually severe rainy season 

 during October 1919 to March 1920, Dr. H. M. W. Edmonds, magnet- 

 ician-in-charge, asssisted by Mr. Albert Smith as foreman-carpenter, 

 made excellent progress on the buildings for the Huancayo Magnetic 

 Observatory. Considerable delay was experienced in connection 

 with the purchase of the observatory site; however, the final titles to 

 the property were legally recorded December 31, 1919. A considerable 

 part of this delay arose from the fact that the land was largely owned 

 on the community plan, and it was necessary to acquire small parcels 

 to make up the whole tract from some thhteen different owners. The 

 site is about 320 meters wide from east to west, with a length north 

 and south of 388 meters on the west and 265 meters on the east, the 

 north boundary being somewhat irregular, conforming to the road and 

 public threshing-areas. The total area of the site is 10.3 hectares 

 (about 25.5 acres.) 



As all building material must be delivered by pack mules over 9 

 miles of poor trail from Huancayo, the assembling of building materials 

 on the site is one of the most difficult features of the work. Orders 

 for the lumber to complete the bill of materials for all the buildings 

 were placed in December 1919. Not until June 1920 could all the 

 materials be delivered at the site. The absolute observatory was 

 practically completed in March, except for the interior lining of wall- 

 board. By the beginning of the rainy season in October 1920 the vari- 

 ation observatory and office and the observers' quarters were under roof 

 and the work of interior finishing was progressing rapidly; it is hoped 

 that the magnetic recording-instruments maybe installed by June 1921. 



During March 18 to March 31, Mr. Fleming, chief of the Magnetic 

 Surv^ey Division, was in Peru and inspected the work at the observatory 

 (see p. 294). Because of the high freight rates and deUvery charges 

 from Huancayo to the site, it was found impossible to consider using 

 sawdust as an insulating material for the magnetic observatory build- 

 ings; accordingly Dr. Edmonds's plan to use straw was adopted. 

 Despite the unusually large diurnal variation in temperature at Huan- 



