780 SEC. 15. GEOGRAPHY. 



3131. Photograph of Paugger's Patent Dromcscope. 



Dr. F. Paugger, Trieste* 



This dromoscope is circular, and has almost the shape of the ordinary 

 chronometer. 



It is about 22 centimeters in diameter, and 7 centimeters in height. On 

 the upper part there is a fixed compass card, with two hands, besides a 

 graduation reading to 45 degrees to the right and left, which lies below 

 these hands (scale of deviation and variation). The inner mechanism of 

 the instrument is a perfect calculating machine ; it exhibits for any desired 

 course the exact tangent formula of the deviation of the compass when the 

 contrivance for turning it has been put in motion. On the lower or back 

 part of the instrument there are five scales or graduations marked A, B, C, 

 D, and E ; and corresponding with these graduations are five set screws 

 (not visible in the photograph). With these adjusting screws, and the scales 

 belonging to them, the five co-efficients of deviation for any ship can be 

 indicated. 



By means of this instrument the deviation of the compass, either of the 

 course or azimuth, is indicated merely by stopping the hand. 



A printed description accompanies the instrument. 



Compass, made in Venice in 1564 by Antonio Blanchini, 

 watchmaker. 



The Royal Institute of " Studii Superiori" Florence. 



Nautical Compass, made in 1607 by Baldassare Lancaeuj, of 

 Urbino. The Royal Institute of " Studii Superiori" Florence. 



Goniometric Compass, of Paolo Massucsiuj, of Lucca. 



The Royal Institute of " Studii Superiori" Florence. 



3099b. Normal Compass of the Imperial German Navy, 

 with stand, sights, two compass-cards, &c. Carl Bamberg, Berlin. 



The normal card A. of the normal compass is arranged for reversal so that 

 at any time a determination of the error of colliraation of the zero-line to the 

 axis of the needle may be effected, and we are enabled to make a deter- 

 mination of the collimation of other cards of ordinary construction, but of the 

 same diameter, by comparison. For measurements on land the gimbals may 

 be fixed and the compass itself be brought to a horizontal position by means 

 of screws. 



3099c. Boat's Compass, adapted to be employed as a small 

 azimuth compass. Carl Bamberg, Berlin. 



The case of the boat compass serves for its transport, and also (by the 

 removal of two pieces) as a binnacle, thus making it a small, handy, and 

 accurate azimuth compass. 



3099d. Boat's Fluid Compass. Carl Bamberg, Berlin. 



The card of the fluid compass is furnished with a float, so that pressure, 

 and therefore also the friction on the pivot, are reduced to a minimum. The 

 cap and pivot are made of ruby, so that they do not easily wear, and a stop 

 becomes unnecessary. 



3O99e. Albini's Registering Steering Compass, 



Elliott Brothers. 



The instrument consists of a steering compass, with clock and apparatus 

 attached, for printing on a slip of paper the direction of the ship's course 



