In 1904 , Slevin was hired by the Academy of Sciences and trained by John Van Denburgh as a scientific collector . In June 1905 the Academy embarked upon a 17-month research expedition to the Galápagos Islands and other Pacific islands with a crew of eight scientists led by Rollo H. Beck ; Slevin was in charge of reptiles . The purpose of the voyage was to study the geology of the islands as well as collect plants , mollusks , insects , birds , mammals , and reptiles , and , as Van Denburgh wrote , " to spare no effort to secure specimens or remains of those races of the gigantic land tortoises which long had been thought extinct . " The voyage made brief stops at islands off of Baja California and the islands of San Benedicto , Socorro , Clipperton , and Cocos before arriving in Española ( also called Hood Island ) in the Galápagos on September 24 , 1905 . During the subsequent year , the expedition found living tortoises on nearly all islands where they had previously been recorded , and living tortoises or their remains for the first time on three islands ( Fernandina , Rábida , and Santa Fe ) . Slevin , aided by 18-year-old assistant herpetologist Ernest Samuel King , took detailed notes on the biology of the animals he collected . Biologists Thomas and Patricia Fritts , who later edited and published Slevin 's field notes , write that although he was " first and foremost a collector of reptiles , he was also a conscientious naturalist who recorded observations in a manner uncharacteristic of the times . " During the expedition , the Academy was nearly destroyed by the 1906 San Francisco earthquake and subsequent fires , and the collection of reptiles and amphibians was reduced from over 8,000 specimens to only 13 . After a full year of exploring the islands , the expedition left the archipelago on September 25 , 1906 , and returned to San Francisco on November 29 of that year . Slevin , King , and others had collected over 4,500 reptiles – nearly 4,000 from the Galápagos alone – which Van Denburgh called " by far the largest and most important collections ever gathered on these islands . " In addition to his field observations , Slevin published the ship 's logbook , which is of historic value to students of the Galápagos
1906 San Francisco earthquake
1906 San Francisco earthquake
Joseph Richard Slevin