[ 498 ] 



D' Ahmlert. See Rotatory Motion. 



Darivm^ Dr. Eral'mus. See Artificial Spring, 



Deal Rods, table of the expanfion of, with obfervations, p. 437. Are improper for 

 very accurate meafurement, p. 438. 



De la Lamh. See JVires. 



De l.ucy Mr. See Specific Gravities, 



Double Stars. Catalogue of, by William Herfchel, Efq. p. 40. Method of pointing 

 out thofe ftars in this colleftion which are not in Mr. Flamftead's Catalogue, p. 41. 

 and of applying it, ibid. Precaution to be obferved where other ftars are very near 

 rhofe to be pointed out, p. 42. The obferver (hould be furnifhed with Flamftead's 

 Coeleltia! Atlas, which muft have the ftars marked from the author's Catalogue, p. 45. 

 Precaution in relation to examining the clofeft of the double ftars, ibid. All the 

 obfervations in this Catalogue are fuppofed to be made with a power of 460, unlefs 

 marked otherwifc, p. 45. Method of taking the meafures of the diftances, ibid. 

 S^c Micrometer. Catalogue of double ftars, p. 47. Firft clafs, ibid. — p. 65. Second 

 clafs, p. 65 — 78. Third clafs, p. 78 — 90. Fourth clafs, p. 91 — 105. Fifth clafs, 

 p. 105 — 118. Sixth clafs, p. 118 — 126. Additional errata to the Catalogue of 

 Double Stars in vol. LXXII. p. 126. See Variable Star. 



JR-agUfione, See Router. 



Earthquakes. See Caribbee I/lands. 



Eclipfies. See Afironomical Qb/er^uaiions, 



Equatorial Micrometer, Mr. Smeaton's recomnacnded, p. 34S. 



Euler^ M. Leonhard. See Rotatory Motion, 



M. John Albert. See Ditto, 



Xxpajfibility, obfervation on that of glafs, with Mr. Cumming's pyrometer, p. 431; 

 See Dtai Rods, 



F 



Tergufon. See FriHion. 



Fixed Air and F'^r/sr appear to confift of the fame ingredients, p. 296. Set Air, 

 Fordyce^ George, M. D. See iVeight. 



Fridlion^ on the Motion of Bodies afFefted by, by the Rev. Samuel Vince, A. M. of 

 Cambridge, p. j6_j. This Ijranch of natural philofophy, nothwithftanding its im- 

 portance 



