CONTENTS. 



CHAPTER I. Methods for Reversed and Non-Reversed Spectrum Interferometry. 



PAGE. 



1 . Introductory 9 



2. Apparatus. Figs. 1,2,3 9 



3. Measurements. First- and second-order spectra. Tables I, 2. Figs. 4, 5 n 



4. Continued. First-order spectra 13 



5. Continued. Second-order spectra. Table 3 14 



6. Theory. Fig. 6 14 



7. Compensator measurements. Sharp wedge 15 



8. Continuation. Revolving plate. Table 4. Fig. 7 16 



9. Continuation. Air column. Tables 5,6 18 



10. Continuation. Babinet compensator. Fig. 8 19 



1 1. Micrometer displacement of the second grating, G' (fig. 3). Table 7 20 



12. Prism method. Reflection. Table 8. Figs. 9, 10, n 21 



13. Prismatic refraction. Figs. 12,13 2 5 



14. Prism methods without grating. Figs. 14, 15, 16 26 



15. Displacement parallel to rays. Table 9 28 



16. Breadth of efficient wave-fronts. Apparent uniformity of wave-trains. Rotation 



of fringes. Figs. 17, 18 30 



17. Film grating. Figs. 19, 20 32 



18. Non-reversed spectra. Figs. 21, 22, 23, 24 34 



19. Non-reversed spectra. Restricted coincidence. Figs. 25, 26 38 



20. The same, continued. Homogeneous light. Dissimilar gratings 43 



21. The same, continued. Duplicate fringes. Figs. 27, 28, 29 45 



22. The same. Prismatic adjustment. Figs. 30, 31 48 



23. Apparent lengths of uniform wave-trains. Tables 10, II. Figs. 32, 33, 34 52 



24. Normal displacement of mirrors (<? = o). Figs. 35, 36, 37 55 



25. Diffraction at M, N, replacing reflection. Table 12. Figs. 38, 39 57 



26. Experiments with the concave grating 59 



27. Polarization. Figs. 40, 41 60 



CHAPTER II. The Interferences of Inverted Spectra. 



28. Introductory 62 



29. Apparatus. Non-inverted spectra. Fig. 42 62 



30. Apparatus and results for inverted spectra. Figs. 43, 44, 45 64 



31. Wave-fronts narrowed. Table 13. Figs. 46, 47, 48 65 



32. Inverted spectra. Further measurements. Table 14 67 



33. Rotation of fringes. Fig. 49 69 



34. Range of displacement varying with orientation of reflector P' 70 



35. Range of displacement varying with dispersion 72 



36. Spectra both reversed and inverted. Figs. 50, 51 73 



37. Experiments with the concave grating 74 



38. Conclusion. General methods. Fig. 52 75 



39. Displacement interferometry. Equations. Fig. 53 77 



40. Continued. Reversed spectra, etc. Tables 15, 16 80 



CHAPTER III. Elongation of Metallic Tubes by Pressure and the Mesurement of the 

 Bulk Modulus by Displacement Interferometry. 



41 . General method and apparatus. Fig. 54 84 



42. Remarks on the displacement interferometer. Figs. 55, 56 85 



43. Observations. Thick steel tube 86 



44. Further experiments. Tables 17, 18. Fig. 57 87 



45. Brass tube. Tables 19, 20. Figs. 58, 59, 60, 61 go 



46. Thin steel tube. Table 21 92 



47. Conclusion. Thermodynamic application. Fig. 62 93 



3 



