under the supervision of ENCKE, was shipped from Hamburgh Oc- 

 tober 18th ; the transit for meridian made by ERTELS, at Munich, 

 is doubtless on its way to the United States. In case no delay 

 occurs in the receipt of these instruments, he expects to have them 

 all mounted and ready for use about the 1st of July next. The 

 magnetic instruments were received about ten days before date of 

 report, and vveie then in course of adjustment in the Observatory; 

 the meteorological instruments were received last May and are safely 

 preserved, the erection of the registering anemometer being delayed 

 until the completion of a superintendent's house. 



Having allowed Mr. GILLISS to explain in his own words all that 

 had been done, up to the date of his report, for carrying into effect 

 the design of Congress, I will now proceed to take a brief notice of 

 the sister observatory of Georgetown College, which owes its ex- 

 istence to private liberality, and, whilst it does great credit to the 

 most worthy Professor, the Rev. JAMES CURLEY, under whose im- 

 mediate care it is placed, at the same time is another proof, if such 

 were needed, of the love of knowledge which characterizes most 

 eminently the distinguished order of which he is a member. 



The donation to which the College Observatory owes its con- 

 struction was made in 1841. In 1842 a plan was agreed upon, and 

 a correspondence opened with European artists, and some of the 

 instruments ordered. The building, was commenced in the sum- 

 mer of 1843, and is nearly finished. The edifice is about four hun- 

 dred yards west by north of the College, on a rising ground, and 

 commands a free view of the Government Depot or Observatory 

 just referred to, which is about 1|- miles to the southeast. The 

 building is sixty feet long, east and west, and about thirty feet 

 wide, and has three rooms on the ground floor. The eastern and 

 western rooms are fifteen feet high, and are intended for the me- 

 ridian instruments. The middle part of the building is thirty feet 

 square and about thirty high, with a balustrade all around, as is the 

 case with the walls of the meridian rooms. A third story of frame- 

 work is constructed within the balustrade of the middle building. 

 It is thirty feet squaie, with a rotary hemispherical dome twenty 

 feet in diameter. This dome rests upon twenty conical eight-inch 

 rollers ; there is a footway three feet wide all around between the 

 dome and balustrade. A solid piece of mason-work is constructed, 

 the top of which passes through the floor of the room formed by 



