16 SEC. 2. GEOMETRY. 



54b. Pantograph, large model, with double scale and reverse 

 action, belonging to the Indian service. Four of these large in- 

 struments are now in use. M. Adrian Gavard, Paris. 



54c. Frame, containing the Drawings of Pantographs 

 and Fantopoly graphs made by the exhibitor. 



M. Adrian Gavard, Paris. 



54d. Pantograph by Adrian Gavard, Paris. 



S. J. Hawkins. 



Size 56 centimeters. 



A method of raising and lowering the tracer A by a rack and pinion 

 movement, for use when the reduction of a drawing has to be made on tracing 

 paper, enables the tracer to pass over any irregularity of surface, and thus 

 prevents injury to the paper. 



There is also a method of ascertaining when the tracer A, the pencil or cen- 

 tral point B, and the fulcrum C, are in a straight line, for use with maps or 

 drawings of irregular scales, and for which there are not any corresponding 

 divisions on the Pantograph. The points A, b, C, D, e are removed when the 

 instrument is adjusted, and the two small screws f, f screwed into the head of 

 the tracer and fulcrum. 



The instrument is adjusted for the reduction of Ordnance maps 25 '34 

 inches to the mile to 5 chains to the inch or 16 inches to the mile. 



54e. Pantograph made at Madrid by Kostriaga, and which 

 has been used at the mines of Almadin since the end of the last 

 century. Royal School of Mines, Madrid. 



Compass of Proportion, called also military compass, 

 invented by Galileo in 1596. 



Royal Institute of " Studii Superiorly Florence. 



On one side are engraved the arithmetical lines, the geometrical lines, the 

 stereometrical lines, and the metallic lines ; on the opposite side are the polygra- 

 fical lines, the tetragonical lines, and the joined lines for the squaring of figures 

 comprised by right angles and curves together. By means of it 40 important 

 operations can be carried on, and it has in addition a quadrant with a squadron 

 of bombardiers, and transversal lines to take the inclination of the scarp of 

 any wall. 



Galileo presented compasses of a similar kind, in the year 1598, to the 

 Prince of Holstein, Sagredo, and Bentivoglio, who was afterwards made 

 Cardinal, to Ottone Brahe, to the Count of Luxemburg, and many other 

 gentlemen, both Italians and foreigners, who had gone to Padua to follow the 

 lectures of so eminent a philosopher. He also presented one made of silver 

 to the Archduke Ferdinand of Austria, and to the Landgrave of Hesse. 



55. Large Collection of Mathematical Instruments 

 for Geometrical and Fortification Drawing, as well as for 

 Artillery purposes. The property of His Highness the Prince 

 Pless, Fiirstenstein. The Breslau Committee. 



This ancient collection, dating from the commencement of the last century, 

 is remarkable for the excellent workmanship and good state of preservation 

 of the instruments. 



