After a few days in London, where he exchanged comments on the spectrum of Mars with Sir William Huggins, he passed on to Paris, and then Marseilles and Costabella where his widowed sister, Katharine Roosevelt, was staying. The eclipse was not to occur until the end of May, but there was much to be done in setting up the instruments, at which he was not needed; so as he saw his sister off for Italy he also bade good-bye for a time to Professor Todd, who left him to look up the telescopic apparatus and get it in place at Tripoli, while he stayed to recuperate for three months on the Riviera.

Here he found William James who, with his wife, was on a like quest to recruit from a similar case of neurasthenia, and at the same time to prepare his Gifford lectures. To his father Percival wrote on April 7: “Professor William James is living here now and we see each other all the time. He is pleased at having just been elected a corresponding member of the Academy of Sciences of Berlin, more for his children’s sake than his own. This when he thought he should never be able to work again, and he wanted them to feel that their father had done something. Now, however, he is stronger and polishes off some Gifford lectures daily, a bit of it.” They saw much of each other, being highly sympathetic physically and intellectually. Like himself, James had recovered, or not lost, his sense of humor, and quoted a remark he had heard “that ethics was a tardy consolation for the sins one had neglected to commit.” And Percival was impressed by his saying that he “considered Darwin’s greatness due to his great detail as increasing the probabilities; showing again how mere detail, mere bulk impresses, though probability be not furthered a bit.” The last part of the sentence may be Percival’s own conclusion rather than that of James, but it had clearly a bearing on his own minute study of the phenomena of Mars.

On the Riviera he made a number of pleasant acquaintances and he was well enough to enjoy seeing people; but, although he was writing a memoir for the American Academy on Venus, he was not yet up to really hard work. After trying in vain to think out mechanical explanations for the small ellipticity in the orbits of the planetary satellites he gave it up, and noted: “I actually am taking pleasure in chronicling this small beer (his solitary walks); pure thought proves so thorny to press.” On April 3d he writes to his father: “I am trying to catch up with you and grandfather Sed longo intervallo so as to solace my solitary walks with fixed acquaintances.” Both of these forebears had been interested in botany. In fact he walked much alone, studying the trees, shrubs and insects, and he writes: “I can converse with plants because they don’t talk back, nor demand attention but accept it.”

The time for the eclipse was drawing near, so after going to Florence to spend a few days more with his sister, he sailed from Genoa on May 16; trans-shipped at Naples, and going ashore in Sicily and Malta while the steamer was in port, reached Tripoli on May 24th. Travelling to out-of-the-way places in the Mediterranean was not a rapid process, and Tripoli then belonged to Turkey; but he found everything prepared by Professor Todd in the grounds of the American Consulate, and, fortunately, when the eclipse occurred four days later the sky was clear and everything went well. He was amused by the comments of the ignorant. “The Arabs,” he wrote in his private journal, “the common folk, told their friends (beforehand) that the Christians lied, and when the affair came off, that they had no business to know being infidel.” But he was as always interested in their ways and habits, mousing about the town with our consul and others, learning about the Turkish troops, and the Tuaureg camel drivers, inspecting a bakery, a macaroni factory, threshing and the weekly fair.

On June 3rd they sailed by an Italian steamer for Malta, but he left it at Tunis to go to the ruins of Carthage, which impressed him greatly; catching the boat again at Biserta, and at Malta trans-shipping again for Marseilles, he made his way to Paris. There the exhibition was open, and among other things he found his exhibit from Flagstaff, “poor waif, in a corner of the Palais de l’Optique and in another place stood confronted by four of my own drawings of Mars, unlabelled, unsubscribed. Felt badly for the poor orphans.” He did not stay long, but went to England, and after spending a few days at the country house of some friends he had made on the Riviera, he sailed for home on July 4th. Shortly before leaving he had received telegrams telling of his father’s unexpected death under an operation, cutting another link with his earlier life.

As yet not well enough to resume his work, he hired a farm house at Chocorua, and settled there on August 3rd for the rest of the summer. He enjoyed seeing the friends and neighbors who spent their vacations there; but, like some other men of science incapacitated by illness, he turned his attention to a field other than his own. As on the Riviera, this was flowers, butterflies, and especially trees; but he studied them more systematically, and with fuller notes. In October he gives a list, covering more than three pages, of the trees and shrubs in the woods, fields and swamps about him in the order of their abundance. This interest he kept up in later years at Flagstaff, corresponding with Professor Charles S. Sargent, the Director of the Arnold Arboretum, and sending him specimens of rare or unknown varieties, some of which were named after him. So highly, indeed, did Sargent rate him that after Percival’s death he wrote a memoir of him in Rhodora,[14] which it is well to transcribe in full:

“That Percival Lowell took an active interest in trees was probably not known to many persons, for he published only one botanical paper and he had no botanical associates except in this Arboretum. It is not surprising that a man with his active and inquiring mind brought up in New England should, when he found himself in Arizona, want to know something of the strange plants which grew everywhere about him and which were so entirely unlike the plants which he had known as a boy in Massachusetts, and later in Japan and Korea. The love of plants, too, was in his blood and only needed the opportunity of this new field to make itself felt.

“Percival Lowell’s great great grandfather, John Lowell, was one of the original members of the Massachusetts Society for Promoting Agriculture and its second President, serving from 1796 until his death in 1802. He is less well known for his connection with rural affairs than his son John Lowell, spoken of generally in his day as “the Norfolk Farmer,” and a generous and successful promoter of scientific agriculture and horticulture in Massachusetts, whom Daniel Webster called “the uniform friend of all sorts of rural economy.” The second John Lowell became a member of the Agricultural Society in 1816 and served from the time of his election until 1830 as its Corresponding Secretary, and as one of the editors of its publication, The Massachusetts Agricultural Repository and Journal. During these years articles by him on agriculture, horticulture and forestry are found in almost every number. In volume v. published in 1819 there is an important paper by John Lowell on “The Gradual Diminution of the Forests of Massachusetts, and the importance of early attention to some effectual remedy, with extracts from the work of M. Michaux on the Forest Trees of North America.” Volume vii. contains articles from his pen on “Some slight notice of the Larch tree (Pinus Larix), known in various parts of the country under the several names of Juniper, Hackmatack, and Larch”; on “Fruit Trees,” signed by the Norfolk Gardener, and on “Raising the Oak from the Acorn and the best way of doing it.” The last volume of this publication which appeared in 1832, when he was seventy-one years old, contains an article by John Lowell on “The Extraordinary Destruction of the last Year’s Wood in Forest Trees and the probable Causes of it”; and on “Live Hedges for New England.” The second John Lowell was active in establishing and maintaining the Botanic Garden of Harvard College and was one of the original members of the Massachusetts Horticultural Society. To the first annual festival of the Horticultural Society held in the Exchange Coffee House on State Street, September 19, 1829, he sent from his greenhouses in Roxbury Orange-trees covered with flowers and fruit and a bunch of grapes weighing three pounds.

“John Amory Lowell, the son of the second John Lowell and the grandfather of Percival Lowell, was deeply interested in botany and in 1845, thirty years after his graduation from Harvard College, began the collection of an herbarium and botanical library with the purpose of devoting himself seriously to the study of plants. He had made valuable collections and a large botanical library when the financial troubles of 1857 forced him to abandon botany and devote himself again to business affairs. His most valuable books were given by him to his friend Asa Gray and now form an important part of the library of the Gray Herbarium. His herbarium and his other botanical books were given to the Boston Society of Natural History. John Amory Lowell, like his father and grandfather, was a member of the Massachusetts Society for Promoting Agriculture. He was succeeded by his son John Lowell, who in turn was succeeded by his son, another John Lowell, who of the fifth generation in direct descent from its second president is now a Trustee of this Society.

“Percival Lowell’s love of plants certainly came to him naturally. I first met him in the Arboretum many years ago examining the collection of Asiatic Viburnums in which he was interested at that time, but it was not until 1910 that he began to send specimens to the Arboretum, including that of an Oak which he had found growing near his observatory and which so far as it is possible to judge is an undescribed species. Interest in this Oak led him to look for other individuals and to extend his botanical explorations. During these he visited Oak Creek Canyon, a deep cut with precipitous sides in the Colorado plateau which heads about twenty miles south of Flagstaff and carries in its bottom a small stream which finally finds its way into the Verde northwest and not far from Camp Verde. Lowell appears to have been the first botanist who visited the upper part, at least, of this canyon where he found a number of interesting plants, notably Platanus Wrightii and Quercus arizonica, which before his explorations were not known to extend into the United States from Mexico beyond the canyons of the mountain ranges of southern Arizona and New Mexico. In Oak Creek Canyon Lowell found a new Ash-tree somewhat intermediate between Fraxinus quadrangulata of the east and F. anomala of our southwestern deserts which will bear his name. Later Lowell explored Sycamore Canyon which is west of Oak Creek Canyon and larger and deeper than Oak Creek Canyon and, like it, cuts through the Colorado plateau and finally reaches the Verde near the mouth of Oak Creek.

“Juniperus in several species abound on the Colorado plateau, and Lowell became deeply interested in these trees and was preparing to write a monograph of our southwestern species. His observations on the characters and altitudinal range of the different species, illustrated by abundant material, have been of great service to me.

“Lowell’s only botanical paper, published in the May and June issues of the Bulletin of the American Geographic Society in 1909, is entitled “The Plateau of the San Francisco Peaks in its Effect on Tree Life.” In this paper, which is illustrated by photographs made by the author of all the important trees of the region, he discusses the altitudinal distribution of these trees, dividing his region into five zones which he illustrates by a number of charts showing the distribution of vegetation in each. It contains, too, an important and interesting discussion of the influence on temperature and therefore on tree growth of the larger body of earth in a plateau as compared with a mountain peak where, on account of greater exposure, the earth cools more rapidly.[15]

“A bundle of cuttings of what is probably a new species of Willow, to obtain which Lowell had made a long and hard journey, with his last letter and a photograph of the Willow, came only a few days before the telegram announcing his death. Botany therefore occupied his thoughts during his last days on earth.

“The death of Percival Lowell is a severe loss to the Arboretum. He understood its purpose and sympathized with its efforts to increase knowledge. Few collectors of plants have shown greater enthusiasm or more imagination, and living as he did in what he has himself described as “one of the most interesting regions of the globe” there is every reason to believe that as a botanist Percival Lowell would have become famous.”