OP THE EXPEDITION. XXIX 



Each co-laborer is requested to send annually to the Superintendent of the National Observa- 

 tory at Washington his observations, with an account of the instruments with which they were 

 made, together with such other information in relation thereto as is necessary to a full under- 

 standing and appreciation of them, and the results arising therefrom. 



M. F. MAURY, 



Lieut. U. 8. Navy. 

 JTXE, 1849. 



In June^ the observatories and all the instruments, except the meridian circle, were shipped 

 at Baltimore on board the "Louis Philippe," bound round Cape Horn, and the vessel being ready 

 for sea, the assistants embarked on the llth of the following month. I hoped to reach Valpa- 

 raiso before them, and supposing that no detention would be experienced on the more expedi- 

 tious route across the isthmus of Panama, none of the portable instruments were reserved 

 except an aneroid barometer and one thermometer. As it resulted, the magnetical instruments 

 would have been an instructive and interesting source of occupation during the weary month 

 passed in that most irksome of all cities on the globe Panama. But I am anticipating. 



On the day following the departure of the assistants, the department was notified of the fact, 

 and advised that there would be nothing to delay my departure beyond the date at which the 

 next steamer would leave for Chagres. And three weeks later the following instructions were 

 received : 



NAVY DEPARTMENT, 



August 6, 1849. 



SIR: Your letter of the 12th ultimo, informing the department that the instruments and 

 other portions of the equipment essential to the observations to be made under the act of Con- 

 gress approved August 3, 1848, have been shipped for Chile under charge of the assistants, and 

 that nothing need now delay your departure, has been received. 



You will be pleased to embark by the earliest opportunity, and proceed to Santiago in Chile, 

 via the isthmus of Panama, and the line of steamers from thence to Valparaiso. On your 

 arrival, you will make known to the consul of the United States there, or other accredited agent 

 of the United States, the object of the Expedition, and request him to make the proper repre- 

 sentation to the Chilean government, with a view to obtain the necessary permission to occupy 

 suitable sites for the observations. The object of the Expedition, as set forth in the act referred 

 to, is to cause "the observations to be made which have been recently recommended (to the 

 department) by the American Philosophical Society and the Academy of Arts and Sciences," 

 of which you have been apprized. After obtaining the necessary permission of the Chilean 

 government, you will select such sites as may be, in your judgment, necessary for effecting and 

 completing the observations contemplated, and proceed without delay to accomplish the object. 



For the pay of yourself and party whilst in Chile, Messrs. Baring Brothers & Co., of Lon- 

 don, have been instructed to honor your drafts. You will keep an exact account of all your 

 receipts and expenditures of public money, taking regular vouchers for all expenditures, send- 

 ing your accounts quarterly to the Fourth Auditor for adjustment. 



The unexpended balance of the appropriations amounts to $4,159 51, which will be placed 

 in your hands, and charged to you on the books of the Treasury Department. 



The department entertains the fullest confidence, that in your ability, zeal and energy, the 

 honorable duty assigned to you will redound to the advance of science, and of the honor of your 

 country and of yourself. 



You will be pleased, from time to time, as opportunities offer, to inform the department of 

 the progress made, and to furnish any other information of a useful character. 



Wishing you success, and the safe return of yourself and party, 



I am, respectfully, your obedient servant, 



WM. BALLARD PRESTON. 



Lieut. J. M. GII.I.ISS, U. S. Navy, Washington. 



