ORIGIN AND OPERATIONS 



equal in each division to 0.2, and extend from 20 to 90. They will all he compared with 

 the standard. 



" Ninth. A wind-vane. 



" Tenth. A rain-gauge. 



" Eleventh. A seismometer. 



" The following books also are necessary: 



iiitical Almanacs, British Association Catalogue of Stars, Lacaille's Catalogue of Stars, 

 Johnson's Catalogue of Stars, Madras Observations, Cape of Good Hope Observations, Tables of 

 Logarithms, IVmiy Cyclopedia, &c. 



"To avoid delay on arrival at the station which may be selected, as well as the risk of obtain- 

 ing suitable materials or workmen, it is proposed to build the observatory and prepare the 

 1'it-rs for the circle in the United States. The building should be at least twenty-two feet long, 

 eighteen lift wide, and eighteen leet high from the ground to the eaves, its floor to be elevated 

 two feet above the surface. The east and west doors will require to be wide and high enough 

 for the stand of the equatorial to pass freely through, and the meridian apertures should not 

 be less than twenty inches wide. Its frame may be of yellow, and the weather-boarding of 

 thoroughly seasoned white pine, thick enough to permit being fitted together with tongues and 

 grooves not less than half an inch square, and in sections of ten feet by four and a half. These 

 sections are to be fastened to the studs and rafters with stout screws, and every part is to be so 

 marked that the house may be put together in a few hours after the piers are in their places. 



"The roof doors will be opened from the inside; and should it be found necessary, a revolving 

 parallelogram of iron, described by Struve in No. 458 Astron. Nach., will be secured to the 

 ridge-pole on either side of the meridian aperture to hold the house together ; but I am not 

 sure that it will not be less liable to injury in an earthquake country without this addition. 

 A box of lattice-work will be made on one side for the thermometers ; and to prevent action of 

 the direct rays of the sun during the mornings and afternoons of summer, Venetian blinds will 

 be erected at the distance of three or four feet to serve as screens. Such a house can be erected 

 by two persons in a few weeks, and, if finished in the best manner, will cost five hundred dol- 

 lars. When taken to pieces, it can be packed for transportation in a small compass. 



"The artist selected to construct the meridian circle should be requested to prepare drawings 

 of the piers that will be required, observing, on account of the possible land transportation, to 

 plan them of the smallest practicable dimensions. Sending these drawings to the United States 

 without delay, the piers should l>e split from the same granite boulder, and dressed and prop- 

 erly boxed at the port from which it is intended to embark the observatory and instruments. 



'It is desirable that the whole equipment be despatched under care of the assistant by the 1st 

 of June, 1849, to the port of Concepcion or Valparaiso, from either of which it may be forwarded 

 in a coasting vessel to the point nearest to its final destination. I propose to leave the United 

 States at the same time, cross the isthmus of Panama, and take the steamer which leaves there, 

 monthly, for Valparaiso, where I shall arrive in about forty-five days. This will enable me to 

 examine for the most suitable station between Santiago and Concepcion, and make all necessary 

 arrangements prior to the arrival of the instruments. 



"There appears to be no dmilit that an inland station will be preferable to one on the coast, 

 because the number of rainy and hazy days is much influenced by the vicinity of the ocean; but 

 it in not possible at this distance to obtain the positive information to justify the selection of a 

 station prior to examination. From all that it has been possible to collect, one of the interior 

 towns on the rivers Mnule or lliobio, just to the eastward of the seventy-second meridian, and 

 south of the thirty-sixth parallel, will most probably be chosen, there being harbors at the 

 mouth of each, and boat navigation which will permit us to transport the equipment with safety 

 and facility. " 



The ]. Piling programme was first presented to the American Philosophical Society, and by 

 it r nimittee which had made the report already quoted. Subsequently it was 



