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results do not differ more than a few degrees from one 
another ; and, when they do, if the bed be examined further 
on, it is often seen that the difference obeys a particular law, 
and results from some gradual change in the direction taking 
place at that part, from the mutual interference of different 
currents, or otherwise. By attending, therefore, to these 
peculiarities of structure, the direction of the current can be 
ascertained with great precision, and also its comparative 
velocity, and I have no doubt, when my inquiries are com- 
pleted, that its rate in miles per hour, will be determinable 
within certain limits. 
I have found it of the greatest advantage to adopt certain 
symbols to express the structures I have described, so that I 
may not only state the direction of drifting of any particular 
bed, but also indicate the exact character of that structure 
by which its velocity may be known. These symbols are 
for — 
Level bedded — Ripple drifted 
Ripple laminated Drift bedded Z. 
I have chosen them with great care, so that they may 
represent, hieroglyphically, the character of the structures, 
be easily written, and also printed by types in common use, 
which are the single dash, and the mathematical sign for an 
angle, the section printed lengthwise, and the same with a 
portion cut away. By writing these down in the order in 
which the amount of each structure preponderates in a sand- 
stone bed, and also signifying the direction of the current, 
most valuable information is afforded of its nature and origin. 
When making the researches included in this paper, I had 
not contrived this useful notation, and hence I am sorry to 
say that I cannot so fully describe the exact character of 
each bed as I could now ; but I trust I shall be able to do so 
with sufficient accuracy for the objects in view on the present 
occasion. Presuming that my methods of research, and the 
