68 RIO JANEIRO. 



that obtained by triangulation. The results will be found in the 

 table. 



Not having time to complete all they desired, some of the party 

 remained over night to complete the interesting observations. Lieu- 

 tenants Emmons and Underwood, on their first trip, obtained many 

 interesting botanical specimens, among them Bromelias, Tilland- 

 sias, &c. 



On the 16th, the Peacock, with the two tenders, sailed for the 

 purpose of measuring the distance between Cape Frio and Enxados 

 observatory. I had first determined to measure the distance by 

 rocket-signals, as the distance, lying nearly east and west, rendered 

 this method very applicable ; but the duties I was engaged in, and 

 the difficulties I might encounter from delays, prevented me from 

 having recourse to it. I therefore adopted that by sound, wishing 

 also to satisfy myself with what accuracy a length of this distance 

 could be measured in this manner. 



Captain Hudson was also ordered to examine the St. Thomas 

 Shoal, to the northward of the Cape. 



The manner of accomplishing the former duty was as follows. 

 The three vessels were anchored in a triangle, with the light-house in 

 sight, two vessels being in range with it, nearly east and west, 

 towards the harbour of Rio. Each vessel firing four guns, the times 

 of the flashes and reports of which were noted in the others. The 

 angles were simultaneously observed between the objects, and the 

 astronomical bearings taken. This gave the data to connect the 

 survey with the light-house. 



The vessels now changed their positions alternately, anchoring in 

 range, and on astronomical bearings proceeding westward, until they 

 reached the island of Enxados, where they again formed a triangle in 

 connexion with the observatory. 



Our repairs in Rio were extensive, particularly those on the 

 Peacock. Among other things, the head of the mizzen-mast had to 

 be cut off eighteen inches, in consequence of a defect in it, which it 

 appeared had been filled up with rope-yarns and putty, and painted 

 over, at her outfit. The defects about the vessel were so glaring 

 that in going to the high latitudes, it would have been impossible to 

 secure the crew from great suffering and exposure. Even in the 

 state in which the squadron w r as now put, I had every apprehension 

 of the greatest disasters. The Peacock, particularly, was wholly 

 unseaworthy with respect to such a cruise. 



My object in giving these details is not to impute blame to any one, 

 how 7 ever satisfied I may be of the great neglect in all the outfits, but 



