Ii6 Account of the Tel ejcope at Kiel, 



lcflening of the weight towards the oppofite fide ; but, as 

 this was not fufficient, the Profeflbr made the horizontal 

 beams to be covered with boards, by which means it ac- 

 quired fd much ballad that the centre of gravity of the whole 

 top retted on the fteel gudgeon c. The fmall balcony con- 

 tains a feven-feet telefcope ten inches in diameter, which 

 the Profeflbr fuflfers always to remain in the open air, and 

 ufes as a hand telefcope. For the greater fecurity, a ftrong 

 iron rod, concealed by the wainfeoting in the infide, is con- 

 veyed along the floor and to the top of the cabin. The 

 lower extremity of this rod ends in two branches fcrewed to 

 the floor, and the upper part rifes one foot above the plat- 

 form. On the top of it is ftuck the key which ferves for 

 moving it; and by lefs than half a turn of this fcrew, the ob- 

 fcrver is enabled to prevent all agitation of the building, be- 

 caufe the rod then prefles with force againft the furface of 

 the horizontal wheel. Properly, however, there are three 

 fcrews, forming an equilateral triangle, which effeft this 

 fattening, two of which in the cabin are very fhort, and 

 the whole are fo arranged, that it is neceflary to move the 

 long fcrew only on the platform. Thus, by its force, it as 

 it were moves the upper platform from its level, and prefles 

 It a little, imperceptibly inclined, towards the two fcrews, 

 which by their preflure on the horizontal wheel prevent all 

 agitation. 



The twenty-fix feet octangular tube, conftrucled of boards 

 which are prevented from bending by a number of knees 

 applied in the infide, and which are made impenetrable to 

 rain, i? lilted to receive a fpeculum of from 19 to 20 Eng- 

 lish inches diameter. At prefent, however, it is furniflied 

 with one of only 14 Hamburgh inches in diameter, having 

 a focus of 26 feet, and which without the frame weighs 80 

 pounds. It is almoft two inches in thicknefs, and towards, 

 the edge caft conical, fo that the diameter of the polifhed 

 furface is almott a quarter of an inch lefs than that at the 

 back. This in the fini filing and poIUhing is of the greatett: 



utility. 



