Commandant #. le Puillon de Boblaye. 195 
the happy idea of employing the geographical engineers in 
constructing a great topographical map of France; a map 
which might supersede that of Cassini, which was concluded 
in the midst of civil discord, and the accuracy of which the 
lapse of time and the progress of the sciences had alike tend- 
ed to impair. Boblaye was connected with the geodetical 
department of this great work; and, along with Colonel 
Bonne, he took part in measuring the perpendicular from 
Brest to Strasburg, on which both geodetical and astrono- 
mical observations were at the same time made, with a view 
to determine the general form of our planet. 
While engaged in this occupation, which lasted for several 
years, our colleague had to spend a long time among the 
ancient formations of Brittany, the geognostical relations of 
which were, as yet, very imperfectly known. Geographical 
engineers are often obliged to remain many successive days 
at a signal-post, on the top of a mountain, till the bad wea- 
ther cease, or a cloud, which covers another signal, be dis- 
persed. In such circumstances Boblaye did not remain in- 
active ; his scrutinizing glance, embracing all around him, 
when prevented examining the heavens, was busily employed 
upon the earth. It is to these circumstances that we are in- 
debted, in part, for the numerous geological observations 
with which he has enriched science, and which, on his return 
to the capital, he communicated to Cuvier, Cordier, Brong- 
niart, &c. It was while exploring Brittany that our inti- 
macy commenced, and I have often had the advantage of be- 
coming acquainted with his beautiful discoveries before those 
under whose direction we both studied. Our colleague was 
long in coming to a determination to publish his work on this 
curious portion of France, although he had amassed a great 
quantity of materials. Influenced by his filial love, as well 
as by his taste for geology, he often returned to this province ; 
and he had examined it in every direction. The first result 
of his researches was the discovery of a new ore of iron, the 
mining of which soon became a new source of riches for the 
country. It was not till the year 1827, that his Lssay on the 
Configuration and Geological Constitution of Brittany,* made 
* Annales du Museum, t. xv. 
