f 
4 
. 
‘ee Se ey 
. 89 
“Thus, through the assistance of others, the Expedition 
would be most efficiently equipped; and the support of the 
Smithsonian Institution, at a very trying period, will always 
be remembered with the sincerest gratitude.” 
Two passed-midshipmen, Messrs. Archibald MacRae, and 
Henry C. Hunter were detailed as assistants, and a young 
civilian appointed as “ Captain’s clerk,” and thus the expe- 
dition was equipped. Before their departure they were 
stationed for a short time at the Observatory, for instruction 
by the officers in charge of the instruments, and employed in 
selecting stars to be designated in advance as objects of com- 
parison. Lithographed charts exhibiting the apparent paths 
of both Venus and Mars during the period of the proposed 
Observations in the years 1849-52, were sent to all the 
northern observatories, since the observations for parallax 
would be available only when combined with corresponding 
observations in the Northern Hemisphere. And inasmuch 
as the co-operation of all other institutions would be matters 
of favor or of scientific zeal, special instructions were issued by 
the Secretary of the Navy to Lieutenant Maury to cause the 
Tequisite observations to be made at the Naval Observatory. 
A circular was also prepared by Lieutenant Maury, and dis- 
tributed to the various observatories of the world, describing 
: the expedition, asking for their co-operation, and requesting 
that the results be sent annually to him at the Washington 
Observatory. ‘ 
The precise place of observation was left to be decided 
Upon Gilliss’s arrival in Chile, the only limits determined in 
advance being the parallel of Valparaiso and Concepcion. 
_ Tt was not till after his arrival in Chile that the city of San- 
tiago was fixed upon, as combining the greatest number of 
advantages ; and there, upon Santa Lucia, a small porphy- 
Titic knoll in the eastern quarter of the city, the observatory 
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