APPENDIX I. 545 



From E. ALBUECHT, University Mechanician, Tubingen, may be obtained 

 the following : 



Large clinostats, after Pfeffer, 320 inks. 



Small clinostats, 220 mks. 



Auxanometer, after Pfeffer, 320 mks. 



Arc indicator, after Sachs, 60 mks. 



Baranetzky's apparatus for registering the flow of sap, 100 mks. 



Horizontal measuring microscope, 125 mks. 



Lever dynamometer, 15 mks. 



Gas chamber, after Engelmann, 15 mks. 



Two-mirror heliostat, after Reusch, 335 mks. 

 Wortmann's clinostat, with all attachments, is to be obtained from 



UNGERER BROS., Strassburg price 200 mks. 



Azotometer : EHRHARDT and METZGER, Darmstadt ; price about 30 mks. 

 Thermostats, thermo-regulators, gas pressure regulators, and gas burners, 



are supplied by Dr. H. EOHRBECK, Berlin, Karlstrasse 24. The 



thermostats specified under 114 and 129 of the 1891-2 price list are 



specially to be recommended. Price according to size, 50-200 mks. 



and 20-30 mks. respectively. I recommend the thermo-regulator 



No. 149 ; price, filled and tested, 19 mks. The thermo-regulators 



(filled with mercury and amyl alcohol), made by HAAK, glass-blower, 



Jena, are also very satisfactory. Price 8-10 mks. 

 Millimetre paper (transparent tracing paper) is to be obtained of 



SCHLEICHER and SCHULL, Diiren, JElheinpreussen. Price for 25 sheets, 



12 mks. 

 Polar planimeter: J. KERN, Aarau, Switzerland. Price, with directions 



for use, 45 mks. 

 All the apparatus mentioned in this book can be obtained from the 



mechanical works of DESAGA, Heidelberg. This firm has specially 



undertaken, either to manufacture the apparatus themselves, or 



procure it from the makers. 



P. P. N N 



