THE CVCLOVE AT BROWNSVILLE, MO., APRIL iS, 1SS2. 245 



for the fact that the distance to the Sun is the hne that is made use of to measure 

 all others in celestial space. And even an error of 100, oco miles would not be 

 of such moment if we used the solar distance but once in a calculation. But in 

 most physical researches, it is involved in the ratio of its cube. Thus, if we raise 

 for instance, 3 to its cube we have 27, but if we raise 3.25 to a cube the product 

 is 34.328 an error far too large to be admitted. It is seen then that the minute 

 error of 100,000 miles when cubed becomes formidable. 



Thus, we cannot tell the distance of Jupiter, nor its weight, size or density, 

 unless we know just how far it is from the earth to the Sun. Kepler's third 

 Law says : that, the squares of the times of revolution of all the planets are in the 

 ratio of the cubes of their mean distances from the Sun. We can all see how long 

 it takes Jupiter to go around the Sun ; then all we have to do is to square this 

 time and extract the cube root, and we have its mean distance. Thus: the earth 

 revolves around the Sun in a time equal to i ; and we observe that Jupiter makes 

 circuit in a period equal to 11.86. The square of 11.86 is 140.66 whose cube 

 root is 5.203, hence we are assured that whatever is the distance of the earth 

 from the Sun, that of Jupiter is 5.203 times greater. Knowing its distance, its 

 mass and volume are revealed by the law of attraction. 



It is well then that observers equipped by the Nations of the earth engage in 

 this the most sublime of problems. The transit will begin on December 6th at 

 8:40 A. M. and pass off at 3:14 P. M. Washington mean time. We have no 

 longitude of Kansas City but making a guess from an ordinary map conclude that 

 it is 18 degrees or i hour and 12 minutes from Washington, hence the transit 

 will begin there at 7:28 A. M. the Sun rising at 7:02. This observatory is iiT 

 preparation to observe the phenomenon. Anybody can see Venus on the Sun. 

 with a smoked glass. 



New Windsor (Illinois) Observatory, July 17, 1882. 



METEOROLOGY. 



THE CYCLONE AT BROWNSVILLE, MO., APRIL 18, 1882. 



W. H. WILLIAMS. 



The terrible agent of destruction which visited Brownsville on the afternoon 

 of the memorable day above named was, perhaps, in some respects, the most 

 peculiar of any one of its kind ever seen or felt by the people in this latitude. 



During the entire day clouds were seen in all directions in the sky; but they 

 were only light, fragmentary ones, the feathery appearance of which did not at- 

 tract more than a glance. It was not until 3:45 that the overcast of the heavens, 

 began to signal the approach of a storm of great violence. 



VI-16 



