THE MAGNETIC OBSERVATORY AT MADISON. 455 



The engine was actually set up in the boat, but at a low stage of 

 the river, and no trial could be made until the river should again rise, 

 some months later. Having no funds to carry them through so long a 

 period, Evans's agents were induced to remove the engine again, and 

 to set it up in a saw-mill, where it created great astonishment by its 

 extraordinary performance in sawing lumber. 



THE MAGNETIC OBSERVATORY AT MADISON, WIS- 

 CONSIN. 



By E. W. DAVIS. 



A VISITOR to the grounds of the State University at Madison, 

 Wisconsin, might perhaps wonder what could be the use of 

 three small chimneys to be seen standing out of the south side of the 

 university hill. On being told that under the ground is one of the 

 two magnetic observatories of this country, he may be curious to see 

 more. If so, he will go on down some distance past the chimneys, 

 and, turning into a moderately deep cut, will enter the observatory 

 through a tunnel in the hill-side. 



Having divested himself of whatever iron he may have about him 

 his keys, his knife, and even his watch two doors are successively 

 thrown open, and he is ushered into a low, vaulted chamber measuring 

 seventeen feet square. The darkness, which would be absolute but 

 for the faint gleams of light escaping through the close coverings of 

 three lamps ; the silence, broken only by the ticking of two clocks, or 

 the tread upon the paved floor; the strange character of the instru- 

 ments, which he begins dimly to see all unite to create a feeling of 

 oppression, as though one breathed the air of some sorcerer's den. 



Though the visitor may be interested in what there is to be seen, 

 yet, in the short time he is allowed to stay, he can get but an imper- 

 fect Idea of it all. He will learn, it may be, the names of the several 

 instruments, and gain a slight knowledge of the manner in which the 

 observations are recorded. He will be told that the observatory was 

 established at Madison in the autumn of 1876 by the United States 

 Coast Survey ; and also, perhaps, that the instruments employed were 

 in use at Key West, Florida, and then at Washington, D. O, being 

 moved from the latter place in order not to be so nearly upon the 

 meridian of a magnetic observatory at Quebec, Canada. If desired, 

 the person in charge will show him some of the traces, one of these 

 being nothing more than the crooked path which a moving spot of 

 light, reflected from a mirror attached to either of the magnets, has 

 left upon sensitive paper. 



