356 M. Delcros' Barometrical Measurement [NoV. 



phical accounts ; but these labours, though brought to great 

 perfection in this respect, are still absolutely defective as far a» 

 profile is concerned. The method attempted of expressing 

 heights by different kinds of shading is exceedingly vague and 

 unsatisfactory. Every person acquainted with the modern 

 improvements, and aware of the importance of a complete and 

 precise topography, would prefer the arid description of a 

 northern geometer to the sweet harmony imported from Italy. I 

 appeal from my own judgment to that of all the civil and mili- 

 tary engineers of all nations. Let not the caprice of fashion and 

 the necessity of yielding to its dictates be alleged. To call in 

 the assistance of painting to that class to whom topographical 

 charts are useless, is to attempt a geographical description of 

 parlours and boudoirs. It is as if we wished to transform the 

 mathematical precision of the Mecanique celeste into familiar 

 conversations on the world. 



The present time may be considered as favourable for the 

 improvement of topography. All nations are eager to introduce 

 into it the rigorous methods which are adapted to it. War could 

 form only engineers skilled in giving a rapid and picturesque, 

 but vague idea of the country which they were called upon to 

 describe. The leisure of peace permits us to demand a superior 

 degree of perfection. Engineers formed in the first schools of 

 Europe promise us what we have long desired. They are quali- 

 fied to fulfil our expectations. Let us not offer them the seduc- 

 ing picture of romance — let us be as rigid and as sage in 

 geography as we are in literature. We possess engineers who 

 are excellent in planimetry. Nothing can exceed the perfection 

 with which they exhibit the horizontal projections of countries ; 

 but another step still remains, which cannot be difficult for men 

 of such skill. Let us take care neither to retard nor to stop this 

 progressive motion, or to convert it into a' retrograde motion by 

 allegations of superannuated authorities. In the sciences, as in 

 the arts, let us never look behind us, except to admire the 

 progress which has been made, and of which we should rather be 

 the emulators than the servile imitators. I have no hesitation to 

 say that a true topographical school, founded on the complete 

 study of the surface of the earth, is still wanting in France and in 

 Europe. When it is formed, and when the complete science of 

 geology is taught in it, we shall then possess engineers capable 

 of describing and expressing every thing. 



Among the improvements proposed for obtaining a good 

 geometrical description of the topography of places adapted for 

 public service, a complete levelling has been proposed, expressed 

 upon charts by the projections of the equidistant curves of the 

 level resulting from the common section of the surface of the 

 ground, with a series of horizontal planes equidistant in a vertical 

 direction. This method is perfect. It is absolutely necessary 

 in order to arrive at the end proposed. Vertical topography is 

 one of the most important bases of every geographical descrip- 



