1868-1871: AGE 61-64.
New Subscription to Museum.--Additional Buildings.--Arrangement of
New Collections.--Dredging Expedition on Board the Bibb.--Address
at the Humboldt Centennial.--Attack on the Brain.--Suspension of
Work.--Working Force at the Museum.--New Accessions.--Letter from
Professor Sedgwick.--Letter from Professor Deshayes.--Restored
Health.--Hassler Voyage proposed.--Acceptance.--Scientific
Preparation for the Voyage.