LIST OF ILLUSTRATIONS. 



Scale and 



FIGURE 



I. — Preliminary Weighing of a Globe ...... 



2. — Hydrostatic Weighing of Small Globes .... 



3. — Collar and Pan for Submersion of Globes .... 



4. — Apparatus for Measuring Compression of Globes on Exhaustion 



5._Discharge Tube of Toepler Pump for Obtaining a Better Vacuum 



6. — Calorimeter Case for Measuring Temperature of Oxygen . 



7. — Apparatus for Preparing Oxygen ...... 



8. — Barometer and Reading Microscopes ..... 



9. — Balance Surrounded with NonConducting Case ; Illumination of 

 Pointer ......... 



10.— Balance, Case, and Metal Box, for Accurate Weighing of Globe 

 II. — Globe Containing Hydrogen for a Standard of Comparison . 

 12. — Mounting of Differential Manometer to Maintain its Position Undisturbed 

 13.— Desiccator for Containing and Manipulating Globes during Filling, Weighing 

 and Exhaustion ........••• 



14. — Clamp for Holding Globe while in the Desiccator 



15.— Filling Globe with Oxygen; Use of Desiccator; Hydrogen Used for Comparison, 

 16.— Balance Standing on the Closet which Contains the Mechanism for Transferring 



Objects from One Pan of the Balance to the Other 

 17.— One Arm of Revolving Carrier, Raised, Hooks Disengaged . 

 18. — One Arm of Revolving Carrier, Lowered, Hooks Engaged . 

 19. — Plan of Reversing Mechanism ...... 



20. — Method of Preventing Leakage of Globes when Exhausted . 



21. — Small Flask for Equalizing Volumes 



22. — Filling a Globe with Oxygen ; Use of Ice . 



22 a. — Desiccator ........•• 



23. — Apparatus for Receiving Hydrogen and Measuring its Volum 

 at Constant Temperature ...... 



24. — Apparatus for Determining Volume of Connecting Tubes . 

 25. — Palladium Tube with no Stopcock ..... 



26. — Palladium Tube, Ready to Connect to Apparatus 



27. — Palladium Tube, Connected to Apparatus, Connection Exhausted 



28.— Second Apparatus for Receiving Hydrogen and Measuring its Volume and 



Pressure at Constant Temperature; Globes without Stopcocks 



29. — Method of Connecting Voltameter and Regulating the Current . 



30. — Connection of Globes to Pump, Serving to Regulate Admission of Gas to the 



Eudiometer ..........••• 



e and Pressure 



PACE 



7 

 8 



14 



17 



19 

 20 



23 



29 

 30 



33 

 34 



35 



35 



39 

 40 



41 

 47 

 48 



52 

 54 



66 

 67 

 70 



71 



71 



n 

 84 



84 



