yuly 16, 1874] 



NATURE 



209 



The purposes of the observatory of the Academy are 

 most effectively secured by confining its workings to the 

 end of educating the cadets in the knowledge and practi- 

 cal use of the instruments. During the spring months 

 they are taken in parties of two, three, or four to receive 

 such instruction, and are required themselves to make 

 observations with each instrument, and reduce them. 

 During the summer encampment a month is devoted to 

 further instruction in connection with a field observatory 

 at Fort Clinton, where they use a field transit, zenith tele- 

 scope, and other instruments. Each makes his own re- 

 cords, and works out his results for the ordinary problems 

 of time, latitude, longitude. Wiirdeman of Washington 

 is constructing for this field observatory a new transit and 

 zenith telescope. 



Although the chief design of the observatory has been 

 from the first to secure such proficiency in the cadets as 

 would prove of most value to them in the field work to 

 which so many army officers are called, and although 

 neither the professors nor their assistants, who are daily 

 instructors in several other branches, can find time avail- 

 able for lengthened series of observations, still at different 

 times valuable observations have been secured in the 

 midst of pressing duties. Among these are those of 

 Prof Bartlett on the great comet of i S43, published in 

 the Transactions of the American Philosophical Society, 

 and recent observations under Prof. Michie and his 

 assistants, Lieut. Bass and others, for determining the 

 longitude of the observatory. 



Anitapfllis Observatory. — We cannot complete this sketch 

 of the United States Government observatories without a 

 just, though necessarily very brief, notice of the obser- 

 vatory used in the instruction of midshipmen at Anna- 

 polis. 



The Department of Astronomy was created in 1853, 

 and until' 1865 was in charge successively of Profs. 

 Chauvenet and Coffin. Since that time a graduate of the 



Academy has from time to time been in charge. The 

 course in astronomy is of necessity limited, most of the 

 midshipman's time in this department being required for 



) -i'u -A L cli 



the study of practical navigation. We learn from the 

 report of Lieutenant-Commander R. L. Phythian to Ad- 

 miral Porter in 1S69 the following facts: — "The instru- 



ments used in this department arc the chronometer, the 

 se.xtant, the artificial horizon, the azimuth compass, the 

 surveyor's chain and compass, the theodolite, and the 

 plane-table. The observatory is supplied with a sidereal 

 clock, an equatorially-mounted telescope, and a superior 

 meridian clock. These instruments are used in instruc- 



tion only to show the midshipmen the principles of them. 

 There is not sufficient time for them to acquire a practical 

 knowledge of their use by observing with them," 



Altogether the United States has reason to be proud of 

 her observatories, and of the work already done by her 

 astronom<:rs. 



