144 REPORTS OF INVESTIGATIONS AND PROJECTS. 



Upon our arrival in San Luis on the morning of September 20 we were 

 met at the station by a party of officials of the Provincial Government of San 

 Luis, including Seiior Don Jose Gazari, acting Governor, Seiior Don Modesto 

 Quiroga, Secretary of State and Finance, Seiior Don Jose Romanella, Mayor 

 of San Luis, and others, together with many prominent citizens of San Luis. 



In order that we might be quartered near the possible site of our future 

 operations it had been arranged that we should enjoy the hospitality of the 

 Escuela Regional, which is under the direction of Dr. C. L. Newton. This 

 proved to be a very convenient arrangement. The site offered by the Na- 

 tional Government was inspected on the day of our arrival and definitely 

 accepted on the following day. It is located on the domain of the Escuela 

 Regional, as already stated, and its altitude is approximately 2,500 feet above 

 sea-level. It is about one kilometer from the principal plaza of the city, but 

 in a position sufficiently isolated from buildings. It is also within convenient 

 reach of the water-supply of the city. This site and its immediate surround- 

 ings constitute a wide-spreading plain extending to the base of the San Luis 

 Mountains about 3 kilometers to the northeast. These mountains add a most 

 attractive feature to the landscape. Owing to the extremely dry climate of 

 the province of San Luis, the terrain supports only a scanty covering of 

 vegetation, except in places where resort is had to irrigation. The plot upon 

 which the new observatory is to be located is under irrigation and covered 

 with a luxuriant growth of alfalfa. The effect of this is greatly to protect 

 the soil from undue variations of radiation — a feature that is naturally of 

 great importance in astronomical operations. The subsoil here offers very 

 great advantages for the construction of piers for the instruments. Under- 

 neath the covering of rich vegetable mold is a stratum of sandy loam, of from 

 3 to 5 feet in thickness. Underneath this again is a layer of gravel of nearly 

 equal thickness, and below that a dry, hardened clay. Nothing better as a 

 foundation for the transit-circle piers could be imagined. 



Within less than a week after our arrival the true meridian was established 

 by observation with a small theodolite, the foundations of the building were 

 staked out, contracts for building material were made and the selected site of 

 the observatory, covered with piles of brick, broken stone, sand, and other 

 material, presented a busy scene. Plans for the observing room, and of the 

 building designed for offices and quarters for the staff of observers, had been 

 prepared previous to our departure from Albany. The transit-circle house 

 is to be constructed of brick with a wooden roof, and contains a single room 

 22 by 23 feet. The office building of brick with galvanized-iron roof is to be 

 approximately 80 by 60 feet in exterior dimensions, with a large interior 

 court, or patio, in the usual Spanish-American fashion. This building is to 

 be of one story and of the simplest construction. Detailed description of the 



