illustrating this paper will, I hope, make the actual geographi- 
j down on a plan, he would have the sections carefully taken for 
_ ‘Mein afew weeks, This plan was accordingly sent to him by 
- work was more tedious than was expected by M. Guillom, 
ot, e did not send me the measured sections until May, 1867. 
the levels of these sections have been taken with the greatest 
» and, I believe, are as precise as any that have been taken 
: Gull. logical purposes ; and I am therefore indebted to Mr. 
— guom for the means of drawing an exact picture of the sur- 
pla m line being mean tide at Havre. The scale of the 
a Feato Tid), is 3} inches to a mile. The vertical scale in 
. a 18 2 Inch to 55 feet, and is three times the horizontal 
ection he dotted lines on the plan show the position of five 
the tes TK, RS, LM,NOP , N Q, nearly at right angles to 
: eel some of them extending to a height of 200 feet above 
‘Tang 7 he line A B is along the Imperial Road. See Plates 
I, Description OF THE LONGITUDINAL SECTION, 
on 8 also a longitudinal section, divided into three parts 
Contin unt of the public buildings at St.-Acheul preventing 
d — levels being taken. The divisions are C D, EF, 
Section. ¢ _ 16 will be treated sometimes in this paper as one 
‘Ac Iong g Dee Plate IV, fig 3, 4, and 5. : 
Ste Esti Sextus, Vou. XLVI, No. 138.—Nov., 1867. 
