Underground of Paris. 155 



sary to say a few words concerning the Observatoire Royale, 

 the place of descent into this very remarkable cavern. This 

 edifice is situated in the Faubourg St. Jacques, in the 

 highest part of the city. It takes its name from its use, 

 and was built by Louis XIV. in 1667, after the design of 

 Claude Perrault, Member of the Academy of Sciences, and 

 First Architect to his Majesty. It serves for the resi- 

 dence of mathematicians, appointed by the King to make 

 observations, and improve astronomy. The mode of 

 building it is ingenious, and admirably contrived, it being 

 so well arched that neither wood nor iron are employed in 

 its construction. All the stones have been well chosen, 

 and placed with a uniformity and equality which contri- 

 bute much to the beauty and solidity of the whole edifice. 

 It is reckoned to be about eighty or ninety feet in height, 

 and at the top there is a beautiful platform, paved with 

 flint stones, which commands an excellent view of Paris, 

 and its environs. In the different floors of this building 

 there are a number of trapdoors, placed perpendicularly 

 over each other, and when these are opened the stars may 

 be very clearly distinguished, from the bottom of the cave, 

 at noonday. 



* At this place I was introduced to one of the inspectors 

 (persons appointed by the King to superintend the workmen) 

 by my friend Mr. Smeathman, who had used great appli- 

 cation and interest for permission to inspect the quarry, 

 and had been fortunate enough to obtain it. For as this 

 cavern is extended under a part of the city of Paris, and 

 leaves it in some places almost entirely without support, 

 the inspectors are very particular as to showing it, and 

 endeavour to keep it as secret as possible, lest, if it should 

 be generally known, it might prove a source of uneasiness 



