314 Prof. Bache’s Lecture on the Gulf Stream. 
In order to present an intelligible summary of the results ob- 
tained by the Coast Survey in the short time allowed for a lec- 
to omit matters at all extraneous to the subjects in hand, an 
confine myself to a brief and direct statement of the means em- 
ployed in examining the stream from tts surface to us depths, the 
method of studying the results, and of the results themselves. 
The temperatures in and near the Gulf Stream, are among 
its most striking peculiarities, and therefore have formed one 
rincipal object of observation. It will be necessary in order to — 
ring the subject within limits, to confine myself chiefly at 
this time to the consideration of this class of facts and to the 
results and laws connected with them. 
I shall proceed therefore to consider the subject under the fol- 
lowing heads: 
1. The Instruments for determining depths and temperatures 
and for obtaining specimens of the bottom. 
2. The plan of research. 
3. The method of discussion of the results. 
Upon the diagrams showing these latter curves, the figure of the 
bottom of the sea is given, where it has been obtained. 
_ Discussion in regard to the cold wall, which is one of the most 
interesting features.of the approach to the Gulf Stream. 
5. The limit of accuracy of the results. 
Stream. 
7. The general features of the Gulf Stream as to temperature. 
6. The figure of the bottom of the ocean below the Gulf 
ture, it is necessary to condense the subject very considerably, 
dto - 
cd 
¥ 
ae 
These points are illustrated by diagrams, enabling the eye! ~ 
follow the results as they are stated. 
I. InstruMEnNTs. 
For Temperatures.—The instrument for determining temper 
ae 
atures should fulfill the two conditions of registering its jndica- 
tions and of being unaffected by pressure. The common merch 
ta 
The ordinary self-registering thermometer, or oltre 
at 
