Mobile register and journal., 1845-04-14

and cIy raised against John Quincy Adams for hav- ing recommended the erection of national ohserva- tory, us senseess and unjust. If any visitor Mho comes to Washington &lll t.ke the trouble iO Vlslt the "Depot of Charls," and exmlne into the merits o( such instituIion he will probably arrive aI the same opinion. All nHvigaturs admit the great ad- Sanisges be derived from fe of nautical al. nanAc, yet such a publication cannot be producrd without astronomical instruments of the best descrIp- ion, employed in lht most. carelu observations.-T IL is fact mol generally known. that both our naval and mercantile service have, until now, had to rely upon the Eng nautical almanac calculations and observations, winch have been supplied from the Royal observatory NJ Greenwleh Such resource IS of course cut of iu time Of war. .... The Depot of Charts is under ihe control 0t tie Bureau oI Aydrography and Charts Its immediate superin,endence is placed in the hands d Lieutenant Maury, Of the Navy, wlo IS well known as stti 0l science and as writer His articles on the delen ces of the Lakes, under the signature of 'Harrv BuIt," published ia the Globe and other papers, have reflected credit on his judgment and ability AS n naval officer.
 Tn. fine instruments in the Observatory q beg pardon, we must call it the 'Depot of harIs, Oh- erwise Congress may refuse to do my thing mure help il aopg,) were bu,lt at Munc One room is appropriated d 0 mural eivole and laige transit instrument In order perf ct steadiness in the working of the instruments, ieir pvots and o . fasenings are fixed on granite pillars, which pro- ject up through the floor, from secure foundations n the ground beneath; that nothing short oi an earthquake oscillations ia the earth itself, can a- feet lllem, In this room there is also clock made fast similar granite pillar, of the most perfect work mauship, which indicates the exact lime. In an opposite room is fine transit instrument of smaller dimensions, with proper, rock constructions for it's movements, and also one ot slIi smaller structure. lH...l nest
 A third room contains the library. Ascending Il pair of stars, the first room entered contains an extensive and splendid collection of charts, maps, etc.. arranged in regular order, according to the part of the world to which they refer.
 | saw many well executed and beautiful charts, published by the British Government, embracing the coasts and harhors of Chil and Peru, made by off cers ordered that service. Here are found charts from every part of the world. a,d in various langua- ges. h 4 United States vessel of war, ordered cruise .o any par of the globe, without difficulty lind charts n this Depot referring to the destined harbor coast ..+--
 Another room on the same floor is appropriated to the regulation of chronomeiers In corner ot the room stands most perfectly constructed ,ne piece or clock. secured 10 pillar of granite, and by the running of which, the running of all the chrononeiers in the room is regulated saw in one case about 20 30 chronometers. all in motion, and undergoing the process Ofregulation.
 In another case ihere were several other standin ng still; suppose waiting theIr turn. Among the chr0- nomeiers, were those of the hest work kanshp 0f all the most celebrated manufacturers in London. l am told Il IS the custom anong London chrOnonleer builders to send out specimens 0 their work to this and other governments Tor ira in competition it others; and If found of satisfactory accuracy, the go vernnlcni keeps them; otherwise, they sent back in good condition 10 the makers. rtt
 On lhe top, the centre of the buldng there is large moveable doine. which is easily trued round by pinion moved by crank, working in spur wheel, equal m sixe and diameter to the dome iisel In the centre of this dome Is erected the Great Te- lescope, which s a superhly finished instrument - h ale lrs Dn a nil nT granite, connected with basement of solid stone masonry, carried up through the centre oi the buItd ing from the ground the observatory, heneath iie movcable dome top. The observers chair, when
 ooking through this telescope, s so arranged as to secure perfect stability; aud yet by ihe movement o crank to the right hand side of the chair, he can lower hoist himself al Lleasure, to accommodate his position 10 the inclination of the ieescope.- On top of the dome there is a pole, up which a ball is hoisled and let fall every day. precisely at l2 M, as is done at the Greenwich Observatory in England.
 The apartments appropriated to magnetic obser- vaions under ground. with central sky-light.- The subcrranean rooms are narrow, meeting from The four cardinal points of the compass, in the Ire. beneath the skylight The steel magnetic dies are placed in the ends of the recesscs-one ho- rixonta. aaother vertical, etc. The, are encloSed in polished copper boxes, and suspended by hair threads. Leading to these short gallery there is a long narrow gallery passage, ofa gra Dl main building. and terminating in the centre of the cross.
 i s said this subterranean structure for the of the magnetic instruments, was intended 10 secure uniform rate of Temperature, during winter and sum | mer, deemed necessary to ,ber accuracy. 4 Owing to some defect in the building of this sub terranean Magnetic Observatory. is at present Ten- dered unfit for use the enters through the wooden ceilings of the roof, floor and sides. standing in pud.lles over parts of the fooring, nearly shoe deep. understand it is the desgno of Lieuien. ant Maury remove the wooden ceilings, and to reconstruct the waIIs sides and roof If good ry. made water proof by hydraulic cement, as to make the apartments permanently available. ."
 The President now receives gentlemen on busi- ness otherwise. daily, from l2 to 2 D. His cial levees still held three times per week, viz: believe on Tuesday, Thursday and Saturday nngs. Although he has sei no hours for the duration of these evees, believe il is desirable they should last from to 10 o'clock p. m. A statement of these matters may be useful to strangers visiting the city, and who may desire to pay their respects to the Pre- sident and lady
 The weather continues mild, warm and spring like.
 l remain yours, very respectfully.
 BENEZETTE.