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i 
Prof. Bache’s Lecture on the Gulf Stream. $21 
; femperatures in the mass of water from 50 fathoms down to 500 
fathoms arc just such as would take place in a mass of water 
heated by conduction from the surface, the law is that of a loga- 
rithmic curve, in which the conducting power of sea water is the 
modulus of the system. 
A comparison of many of these curves with the logarithmic 
form showed that it was applicable to them within the limits of 
_ the probable error of the observations. Taking the warm stra- 
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tum from the Gulf of Mexico above and the cold polar stratum 
below, the mass of the water between is heated by conduction. 
The bottom of the sea has not been reached under the axis 0 
the Gulf Stream, north of Cape Lookout on the North Carolina 
st. 
coast, 
This form of curve was deduced in 1844 from the observations 
of Commander Charles H. Davis and was the first discovery 
made in connection with the then recently commenced system- 
atic exploration of the Gulf Stream by the Coast Survey. 
2. Nos. 2, 8, and 8 bis, Plate I, are specimens of the type- 
curve in the Gulf Stream, taken from the sections off Cape Henry, 
ape Hatteras and Charleston, being characterized by the com- 
rely short beak or projection and the persistence of the 
igher temperature to great depths as 55° to 425, 450, 550 fath- 
oms giving the peculiar shape to this curve between 50 and 
500 fathoms. 
Tl. Typx-curves oF DISTRIBUTION OF TEMPERATURE ACROSS THE STREAM, 
(@.) Curves of temperature at the same depths.—The sections 
made are the following, beginning the enumeration at the Gulf 
of Mexico: 1. Tortugas to Havana. 2. Sombrero Key to Salt 
5. Off Cape Cafiaveral. 6. Off St. pain: ore 7. Off St. Si- 
ap 
toeach hundred miles along the axis of the stream. These are 
marked on the general chart, Plate III, the names of the ~ 
Plorers being stated in the column which gives the point o 
The Sandy Hook curves, Nos. 4 and 5 Plate I, are among the 
best of the type-curves of temperatare = > oe sa na 
amon arli y secmale 
eae the earliest determined. _ cold current between it and 
the shore, mixing in a degree with the cold water, is well shown 
- fithoms @, e, f) The whole space from the shore to 240 miles, 
