INDEX. 523 



Page 



Light>House illumination, Henry's investigations in 97,309,312,421,502 



Light-House service greatly improved by Henry 97,308,315,436 



Lightning-rods, observations on , 261 



Lightning-rods suggested for telegraph poles.*. 262 



Liquid cohesion found to be equal to solid cohesion 265,498 



List of Henry's scientific papers 365 



Longitude determination by simultaneous observations on meteors 271 



Loss of valuable scientific papers by fire, in 1865 305 



Levering, Prof. Joseph, obituary memoir of Henry, by 427 



McCosh, Rev. Dr. J., appointed by the Regents to offer introductory prayer at the 



Memorial Services 29 



McCosh, Rev. Dr. J. opening prayer by, at Memorial Services 39 



Maclean, Dr. John, account by, of Henry's election to Princeton J.68,238 



Maclean, Dr. John, one of executive committee appointed by the Regents to 



make arrangements for a public commemoration 1, 28 



Maclean, Dr. John, one of a select committee appointed by the Regents to pre- 

 pare a biographical sketch of Henry 28 



Maclean, Dr. John, prayer offered by, at meeting of the Regents, on the death 



of Joseph Henry 27 



Maclean, Dr. John, resolution of thanks presented by, at meeting of the 



Regents 34 



Maclean, Dr. John, resolution presented by, at meeting of the Regents, rela- 

 tive to preparation of a Memorial Volume 31 



Magnet, Henry's Albany, of 750 pounds, made in 1830, for the Academy 220 



Magnet, Henry's New Haven, of 2,300 pounds, made in 1831, for Yale College 229 



Magnet, Henry's Princeton, of 3,500 pounds, made in 1835, for the College of 



New Jersey 244, 484 



Magnet, Intensity, for acting at a distance, made by Henry in 1830 223, 227, 488 



Magnetic expansion of iron tested by Henry 329 



Magnetic needle by galvanism, first produced by Arago 213,479 



Magnetic telegraph first made possible by Henry 93, 225,486 



Magnetic telegraph invented by Henry _ v 85, 131, 149, 228, 380, 487 



Magnetism, by means of a galvanic current, first developed by Arago 213,479 



Magnetism, terrestrial, observations by Henry on the intensity of 258,445 



Magnetizing " bobbin " first devised Iby Henry 217 



Magneto-electricity first attempted by Fresnel in 1820 233 



Magneto-electricity first discovered by Faraday in 1831 .234,446 



Magneto-electricity independently discovered by Henry early in 1832_61, 235, 445, 490, 493 



Marriage of Joseph Henry to Miss Alexander 61,238 



Mathematics, attainments of Henry in 208,443 



Mathematics, Henry, professor of, at Albany Academy 57, 130, 211 



Meads, Dr. O. account by, of Henry's early experiments 375 



Meads, Dr. O. memorial minute by, on the death of Henry 130 



Meads, Dr. O. testimony of, to Henry's early magnetic telegraph 131,380 



Medal, Copley, proposed for Henry, by Faraday and Wheatstone 506 



Memorial minute for the Albany Institute, by Dr. Orlando Meads 130 



Memorial Services appointed by Congress, to be held in the Hall of the House of 



Representatives, United States Capitol 37 



Memorial Services at the Capitol, arrangements for 29 



Memorial Services at the Capitol, held on the evening of January 16, 1879 2, 38 



Memorial tribute to A. Dallas Bache, by Henry 330 



Memorial Volume in honor of Joseph Henry, directed by the Regents 31 



Memorial Volume in honor of Joseph Henry, the printing of 15,000 copies of, 



ordered by Congress 4 



Memoir of Henry by Prof. Henry C. Cameron , 166 



Memoir of Henry by Rev. Samuel B. Dod 139 



Memoir of Henry by Prof. Asa Gray 53 



