VOL. XXXIII.] I'HILOSOPHICAL TRANSACTIONS. 107 



Distance, inches, lines, grains of attraction. 



• n 



• H 



. 3 



• 9 



. 12 

 . 23 

 .23-1- 

 . 26+ 

 ,29 



8 304 



But here again occur great irregularities, from which nothing can be con- 

 cluded: this only is surprising, that though the magnet used in the second 

 experiment was smaller than that in the first, yet in the point of mutual con- 

 tact it was attracted with equal forces, namely, 340 grains, while in other dis- 

 tances the attraction was much less, as appears from comparing both tables; 

 but besides, this smaller magnet was more vigorous and much better at raising 

 the iron than the magnet in the first. 



He repeated these experiments with other magnets, and particularly with one 

 whose force was so great, as to affect a magnetic needle at the distance of 14 

 Rhinland feet. But from all the experiment^ he could only conclude, that there 

 is no assignable proportion between the forces and distances. 



Since both the declination and inclination of the magnetic needle vary almost 

 every year, he wished to observe, whether the force of the magnet was the 

 same every day, or greater or less in summer than in winter; but he found by 

 several experiments, that the force is less in summer than in winter, at least in the 

 summer of 1 725 ; whether it will be the same in 1 726, must be then discovered. 

 He therefore took the two magnets used in the first experiment, and on 

 July 23, 1725, when the barometer was at 29^"^ inches, he made experiments 

 with them, altogether in the same manner, and in the same part of his house 

 as before. M. Fahrenheit's thermometer was at 62 degrees, the wind N. W. 

 the sky serene, and the weather dry. . 



Distance, inches, lines, grains of attraction. lines. 



7 106 



6 Ill 



5 132 



4 149 



3 173 



2 205 



1 240 



oi 270 



300 



