OPPOSITION OF M. DE LAPLACE. 81 



cms comets, and calculated their orbits. I had, in concert 

 with M. Bouvard, calculated, according to Laplace's for- 

 mula, the table of refraction which has been published in 

 the Recueil des Tables of the Bureau of Longitude, and 



o 



in the Connaissance des Temps, A research on the 

 velocity of light, made with a prism placed before the 

 object end of the telescope of the mural circle, had 

 proved that the same tables of refraction might serve for 

 the sun and all the stars. 



Finally, I had just terminated, under very difficult cir- 

 cumstances, the grandest triangulation which had ever 

 been achieved, to prolong the meridian line from France 

 as far as the island of Formentera. 



M. de Laplace, without denying the importance and 

 utility of these labours and these researches, saw in them 

 nothing more than indications of promise ; M. Lagrange 

 then said to him explicitly : 



" Even you, M. de Laplace, when you entered the 

 Academy, had done nothing brilliant ; you only gave 

 promise. Your grand discoveries did not come till after- 

 wards." 



Lagrange was the only man in Europe who could with 

 authority address such an observation to him. 



M. de Laplace did not reply upon the ground of the 

 personal question, but he added, " I maintain that it is 

 useful to young savans to hold out the position of mem- 

 ber of the Institute as a future recompense, to excite 

 their zeal." 



" You resemble," replied M. Halle, " the driver of the 

 hackney coach, who, to excite his horses to a gallop, tied 

 a bundle of hay at the end of his carriage pole ; the poor 

 horses redoubled their efforts, and the bundle of hay 



