Telegraphic Determinations of Longitude. 17 
time, if he escaped, disease would have had the certainty. of being 
quarantined from entering the United States for three weeks or 
a month after leaving Mexico. 
Upon the completion of the West Indian work, and the publi- 
cation in 1877, of the results, it was determined by the Bureau of 
Navigation to send an Expedition for the same purpose to the 
east coast of South America. Cables were in use extending from 
Para in northern Brazil to Buenos Ayres in the Argentine Re- 
public. A cable had at one time connected this system with the 
West Indies, through British Guiana and Trinidad, but one of 
the links was broken and there was no prospect of its repair, 
otherwise the Station established at Trinidad in 1874 might have 
been taken as the starting point. There was direct communica- 
tion however between England and Brazil, by the way of Portu- 
gal, and the Madeira and Cape de Verde Islands. Lisbon seemed 
to afford the most convenient place to start from, but its longi- 
tude had never been determined by telegraph and it was decided to 
request the French Bureau of Longitudes to codperate by making 
this measurement from Paris. This request was readily granted, 
but for some reason the agreement was not kept. For the use of 
the Expedition the old fashioned sailing ship Guard was furn- 
ished and Lieut. Com. Green was given command. Mr. Rock 
being otherwise employed his place was taken by Lieut. Com. 
(now Commander) C. H. Davis, U.S. N. The instruments hav- 
ing been placed in good order, and new supplies furnished where 
necessary, the expedition sailed from New York for Lisbon in the 
latter part of October, 1877. The Guard was a slow sailer, 
the weather was rough and the wind generally ahead, conse- 
quently a month was consumed in making the passage. It was 
the intention to make the first measurement between Lisbon and 
Funchal, Madeira. Lieut. Com. Davis with party and instru- 
ments occupied the latter station, proceeding by mail steamer at 
the first opportunity. The cable from England does not land 
directly at Lisbon, but at a small town called Carcavellos on the 
coast about twelve miles from the city. As it was not practicable 
to connect the land line from Lisbon direct to the cable, it was 
“necessary in making the exchange of signals to adopt another 
method, or rather combination of methods. An officer of the 
ship was sent to Carcavellos, furnished with a chronometer and 
chronograph. When the time came for exchanging signals, he 
first compared his chronometer with that at Lisbon, by the auto- 
VOL. II. 2 
