academ, of sciences] SCIENTIFIC RELATIONS 141 



are recorded here in order that future historians and economists may know the conditions of 

 life imposed in the latter part of the nineteenth century by the richest country in the world 

 on one of the ablest men in its service. It may be added that in 1889 the Corcoran Street 

 house was painted; that event being here chronicled, not because of its intrinsic importance, 

 but because it serves to introduce a characteristic passage from one of Gilbert's letters to an 

 intimate correspondent: 



I have had my house painted a pale green-gray and the trimmings a deep but rather quiet green — window 

 sashes red. I know it is all right, first because I got Mr. Gill, one of our [Survey] artists, to tell me what colors 

 to use, second because it looks all right. If someone tells you you are happy and if you feel happy, why of course 

 you are happy. 



After mention of other members of the family, the letter continued: "The old man is still 

 serenely bobbing upwardly." 



Gilbert had great need of his serenity, for his wife's health had changed from bad to worse 

 and in time reached the stage of chronic invalidism. As she could give little care to the house- 

 hold, the two boys spent a large part of each year with their uncle at Rochester or at boarding 

 schools and summer camps; the "old man" was much alone. Although he gave every care and 

 made every effort to restore his wife to health, she never recovered her strength. His devoted 

 attention during the long period of her invalidism excited the admiration as well as the sympathy 

 of his associates. Even when oppressed by care and grief, his patience was untiring, his 

 though tf ulness unfailing; and as far as the outside world could see his serenity was preserved 

 unruffled. Indeed, so buoyant was his nature and so well was he sustained at time of trouble 

 by a courageous and cheerful philosophy, that in spite of the disappointment caused by the 

 transfer of his work from the Great Basin to the Appalachians, and in spite of the distractions 

 caused by home cares, his life always seemed to be joyous. 



GEOLOGY OF THE APPALACHIANS 



The Sixth Annual Report of the National Survey for 1884-85 announced that Gilbert, then 

 a little over 40 years of age, had been placed in charge of the division of Appalachian geology, 

 but the next year he was relieved of its Archean rocks. Gilbert commented on the task thus 

 assigned to him as differing from his previous work "not only in its character but in the fact that 

 it already possesses a copious literature." It may be doubted whether the resulting necessity 

 of looking up all the fragmental studies of his many predecessors made the Appalachian field 

 attractive to his original and independent mind. However, he accepted the duty and reported 

 for 1885-86 that a comprehensive subject-bibliography of Appalachian geology had been begun, 

 and that under his direction some 6,000 bibliographic cards had been prepared; the next year 

 the number of cards reached 11,000. A later consequence following from this particular man- 

 ifestation of Gilbert's all-round capacity was his appointment in 1891 as the American member 

 of an international commission, under the chairmanship of de Margerie of Paris, to prepare a 

 bibliography of geological bibliographies, which was published in 1896, as noted below. In the 

 meantime, the completion of the Bonneville report was still delayed. 



Appalachian field work was begun in the second half of 1S84, when Gilbert spent a fortnight 

 of August in the mountains of North Carolina, Tennessee, and Georgia. It is significant that 

 his observations there were not stratigraphic, but had "special reference to the terrace system 

 of the mountain valleys," a distinctly physiographic problem. Three weeks were given some- 

 what later to similar studies in New England and eastern New York; and from this it may be 

 inferred that the chief of the Appalachian division expected to gather a larger volume of novel 

 results by the application of new methods of physiographic interpretation, learned in the West, 

 to this long-studied eastern region, than could be gained in the same amount of time from a 

 revision of its stratigraphy. The physiographic nature of his interest in the Appalachians was 

 further emphasized in his administrative chapter of the annual report for 1885-86, in which it 

 was announced that he reserved for his own study the "evidence of elevation and subsidence 

 existing in the topography of the entire district." But although his intention thus appears to 

 have been all-embracing at first, his published work on the modern or physiographic phase of 



