53 



can not fail to admire the union of practical wisdom with 

 theoretical foresight which led to the adoption of a basis 

 of measurement, at once so universally accessible and yet 

 susceptible of sufficient accuracy for all ordinary purposes 

 in an early stage of society, as that derived by these 

 ancient egyptian priests from the dimensions of the human 

 body. Indeed it is only in France, in this respect the 

 modern Egypt, that any attempt at a more precise and sys- 

 tematic basis has been made ; but even now it is to be 

 regretted that the french savans did not recur at once to 

 the best possible basis afforded by nature herself, and now 

 perfectly accessible under the precision of modern methods 

 of astronomical observation, to wit, the natural and invari- 

 able unit of time formed by one complete rotation of the 

 earth on its axis, and constituting the sidereal day. The 

 length of the mathematical or simple pendulum that should 

 beat sidereal seconds in vacuo at the equator, at the level of 

 the sea, would form a standard unit of length, acceptable 

 to all nations, and more readily determinable by calculation 

 and experiment than was the ten-millionth part of the 

 quadrant of a meridian of the earth's surface. 



England, that glorious country of our ancestry ; whose 

 noble people have individually done so much for the im- 

 provement and elevation of humanity, but who collectively 

 even to this day lend their mighty force to the prolongation 

 of venerable errors, to the perpetuation of ancient abuses, 

 and to the strangulation of all attempts to curtail them : 

 England, in its plenitude of practical wisdom, offers the 

 following system of incommensurable quantities as all the 

 progress admissible in an attempt to regulate measures and 

 weights according to a uniform scale. The length of the 

 pendulum that beats mean solar seconds at London (lat 51° 

 31' N.) in vacuo at the sea level, is divided into 391393 

 equal parts, 10000 of which parts constitute the imperial 

 inch : the weight of a cubic inch of distilled water, at the 

 temperature of 62° F., is divided into 252458 equal parts, 



