CONTENTS. 





ORIGIN AND OPERATIONS OF THE EXPEDITION i-xlii 



Dr. C. L. Gerling suggests a new mode for determining the solar parallax iii-iv 



An expedition to the southern hemisphere proposed jv 



A brief account of the climate of Chile -- v-viii 



The instruments necessary for the observations --.--.-..-.. viii ix 



Opinions of American astronomers .-.----.._.-.. x-xi 



Results which may possibly be obtained .-..'----_.._. xi-xiv 



Resolutions of the American Philosophical Society and Academy of Arts and Sciences - - - xiv-xv 



Report of the Naval Committee of the House of Representatives in favor of sending out an expedition - - xv-xvii 



Appropriation of funds by Congress xviii 



Proposed plan of operations xviii-xxii 



Approbation of the programme by the Societies and Department - xxii-xxiii 



The Meridian circle ordered from Messrs. Pistor & Martins xxiii 



Defective condition of the instruments supposed available - xxiv 



The Smithsonian Institution authorizes the purchase of a ill-inch Equatorial, to be loaned to the expedition - xxiv 



Telescope made by Win. J. Young and Henry Fitz satisfactorily tried -------- xxv 



Congress appropriates money to pay for the telescope, &c. .-..- xxvi 



Interest manifested in the expedition and valuable services rendered by scientific men in England - - xxvi 



Officers ordered as assistants, and preparation of the ephemerides ..-..-.. xxvi-xxvii 



Circular to the friends of astronomical science ---- xxvii-xxix 



Sailing of the assistants with the equipment ------ - xxix 



Instructions from the Secretary of the Navy - xxix 



Instructions from the same to Lieutenant Maury, Superintendent Naval Observatory xxx 



Departure from the United States and arrival in Chile xxx 



Favorable reception by the government at Santiago de Chile xxxi 



Reasons for selecting Santiago for the observations - xxxi 



The site chosen for the observations xxxii 



Arrival of the assistants and equipment ---- xxxii 



Erection of the observatories on Santa Lucia - ------------ xxxii 



The instruments mounted and work commenced ------------ xxxiii 



The government desires to have some of its young men instructed in practical astronomy xxxiii 



Interest and curiosity of the public- ...... xxxiii 



Progress of the observations of the planets Mars and Venus - - - - xxxiv-xxxv 



Extraordinarily favorable condition of the atmosphere xxxiv 



Visit to the northern provinces of Chile - xxxv 



Zone observations and star magnitudes xxxvi 



Variations in the brilliancy of n Argus - xxxvi-xxxvii 



Visit to Talca. and the river Maule xxxvii 



Establishment of the OnsERVATORio NACIONAI. ............ xxxviii 



Observations during our last year in Chile .--...-..... xxxviii-xxxix 



Two occultations of r; Geminorum on the same evening ----- xxxix 



Meridional distance between Santiago and Valparaiso ----------- xxxix 



Magnetical and meteorological observations - ............ xxxix xl 



Transfer the observatory and take leave of the government ---------- j\ 



Lieut MacRae is instructed to proceed across the Andes and Argentine provinces for special observations - xl xli 



Return of the expedition to the United States - xlii 



OBSERVATIONS OF THE PLANETS MARS AND VENUS. 



INTRODUCTION 



Description of the observatory -..--..' j\ v 



Description of the Equatorial .._........-.... x i v ; 



Observations to determine the position of the instrument xlvii 



Instrumental deviations ----- xlvijj 



Value of a revolution of the micrometer screw xlviii 



Diameter of the micrometer wire xlviii 



