CONTENTS. 



*CHAPTER I. An Interferential Contact Lever with Achromatic Fringes. 



PAGE 



1. Apparatus. Figs, i, 2, 3 7 



2. Equations. Fig. 4 



3. Observations. Figs. 5, 6 10 



CHAPTER II. Elastic Deformations of Small Bodies Measured by the Preceding 



Contact Lever. 



4. Introductory - 13 



5. Apparatus. Figs. 7, 8 13 



6. Observations. Hard rubber. Figs. 9, 10. Table I 14 



7. The same, continued. Fig. 1 1. Table 2 16 



8. The same, Brass. Figs. 12, 13, 14 17 



9. The same, continued. Figs. 15, 16, 17 19 



10. The same, continued. Figs. 18, 19, 20 21 



u. Glass. Figs. 21, 22, 23, 24, 25, 26, 27, 28 21 



12. Conclusion 24 



CHAPTER III. The Elongation Due to Magnetization, Measured with the 



Interferential Contact Lever. 



13. Introductory 25 



14. Apparatus. Fig. 29 25 



15. Observations. Figs. 30, 31 ... 27 



16. Vibration telescope. Fig. 32 29 



1 7. Theoretical observations 30 



18. Further observations. Figs. 33, 34. Table 3 31 



19. Magnetic elongations in a free-end coil. Figs. 35, 36 33 



20. Coefficient of expansion. Figs. 37, 38, 39 34 



CHAPTER IV. On the Pressure Variation of Specific Heat in Liquids. 



21. Introductory 37 



22. Equations. Fig. 40 37 



23. Measurement of the pressure coefficient /? 38 



24. Measurement of the thermal expansion a 38 



25. Available liquids 39 



CHAPTER V. A n Electrodynamometer Using the Vibration Telescope. 



26. Introductory 41 



27. Apparatus. Figs. 41, 42, 43 41 



28. Observations. Figs. 44, 45 44 



29. Further observations. Fig. 46. Table 4 45 



30. Effect of frequency. Figs. 47, 48, 49, 50, 51 46 



31 . Steel wires 47 



32. Adjustable telephone 48 



33. Coil tester. Figs. 52, 53, 54 .- 4& 



34. Heavier armature and less damping. Fig. 55 51 



35. Further magnification. Fig. 56. Table 5 52 



36. Organ-pipe. Fig. 57 53 



37. Equations 54- 



CHAPTER VI. The Rapid Telephonic Vibrator on the Interferometer. 



38. Introductory 55 



39. Apparatus. Figs. 58, 59 55 



40. Observations with the slit-image 56 



41 . Observations with the interferometer. Fig. 60 57 



42. Decreased bifilar distances. Fig. 61 58 



43. Observations with the new apparatus. Figs. 62, 63 59 



44. Capacity and self-induction in the secondary. Figs. 64, 65, 66, 67 61 



45. Self-induction in the primary. Figs. 68, 69 62 



5 



