Translation from the AstronomicalJour. of HamlurgJt. 227 



to be supported independent of them. The axis of the tran- 

 sit is thirty three inches long, which also corresponds to the 

 views of Rcichenbach, who considers long axes as not ad- 

 vantageous; the cylindrical parts are of bell metal, as usual 

 with the English artists. The supports are not between the 

 pillars, but upon them ; a strong metal plate is fixed upon 

 the middle of the pillar, bearing the parts which move the 

 Ys, and these are moved in the direction of the meridian by 

 screws, by which the adjustment to that direction is made ; 

 the usual vertical screw is not in the arrangement; instead of 

 this, the piece bearing the Ys, is formed like an arch, the mid- 

 dle of which is supported by a screw, the higher or lower 

 position of which, elevates or depresses it by the different 

 degree of tension of the metal which is produced by the 

 action of the screw and its own elasticity. This method 

 promises to secure complete stability ; but it is supposed that 

 the two pillars have the same altitude, and also that no re- 

 markable change should take place in them. The counter- 

 poising apparatus is placed about five inches from the end, 

 and consists of springs, which press rollers under the axis, 

 performing what Reichenbach effects by levers and weights. 

 By Mr. H's arrangement, this counterpoising apparatus oc- 

 cupies the place on the pillars, which the supports formerly 

 did; this arrangement likewise appears to me good; whether 

 it would be applicable to very heavy instruments remains still 

 to be tried.* The two conical axes are not joined by a cube 

 in the centre, but by a zone of a sphere of eight inches di- 

 ameter, to which the two parts of the telescope tube are 

 screwed ; this arrangement is made with a view to greater 

 stability. 



Of the other instruments of Mr. H. it will not be possible 

 to give an adequate description without drawings, but I may 

 however indicate some of their peculiarities. The theodo- 

 lite of two feet, not constructed for repetition, appears to me 

 to possess a peculiarly good construction. From a hexago- 

 nal centre piece emanate six horizontal conical arms, whose 

 bases are three inches, and ends one and a half inches in di- 

 ameter. Upon these arms the two feet horizontal circle is 

 made fast; three of these cones are longer; these contain 



* The transit of the observatory at Greenwich is adjusted in this manner, and 

 as it is ten feet in length, the doubt whether the plan be applicable to lar^e in- 

 struments is settled by actual experience. 



