Albert Ott, Kempten. 



55 



2. 1 Planimeter, arranged for a fixed ratio of 1 : 1000 (metric 

 system) only. 



3. 1 Planimeter (Fig. 2) with adjustable tracing-lever and needle- 

 pole, with guide-ruler, adjustable for any measure or any ratio, also suitable 

 for computing indicator-diagrams. The wheel has a circumference of exactly 

 66 mm; the tracing-pin and the pole-axis have at their ends points 

 for fixing the basis of the diagram. Each division read off by vernier 

 on the wheel represents 0,15 m (mean ordinate of the diagram). 



4. 1 Planimeter with adjustable tracing-lever, suitable for all 

 measures and ratios. With pole weight and controlling surface; with 

 glass wheel. 



AVith all these planimeters the wheel has for the last 10 years 

 been supplied with the divisions marked on celluloid; the adjustable 

 tracing-lever is provided with scale, vernier and pointer for adjusting 

 the required ratio. The wheels are usually made of steel, only if 

 specially desired they are made of glass. Over 1000 of these instruments 

 have been supplied. 



Fig. 3. 



5. 1 Current meter (Fig. 3), smallest size, with counting wheels 

 for 800 revolutions; attachable to a wood plank; dissectable; in pocket 

 folding case; pitch of vanes 0,15 m. 



6. Current meter, medium size, with counting wheels for 2000 

 semi-revolutions. The propeller spindle runs in agate bearings; the 

 instrument is provided with mechanical releasing and fixing gear, with 

 pulley and clamp for vertical movement along an iron slotted tube. 

 Pitch af vanes 0,3 m. 



7. Current meter, large size, with electrical transmission of the 

 revolutions to bell and speed indicator may be raised and lowered along 

 a fixed vertical rod; suitable also as a floating vane for showing rate of 

 flow of surface-water. Pitch of vanes 0,50 and 1 -m. 



(The instruments Nos. 6 and 7 have been constructed according to 

 the directions of Prof. A. R. Harlacher of Prague.) 



