from the fact that a point of inflection is a property of the cubic. On the other hand there is some slight a priori ground for supposing the demand curve to be of the hyperbola type, a curve without points of inflection. In the case of the value of money, it can be demonstrated that the demand curve is the equilateral hyperbola. As Karl Pearson has pointed out, the problem in curve-fitting lies quite as much in the selection of the right type of curve as in the fitting of it to the data when selected. Accordingly the experiment was tried of fitting equilateral hyperbolas to the data for the above mentioned staple crops. The method of moments was employed, the method of least squares being inapplicable. The results obtained in the case of corn and oats are shown in Figures 4 and 5.

In conclusion it is fair to say that Professor Moore's volume is most suggestive and stimulating. Yet it may be questioned whether the main contention of business cycles based upon rainfall is fully proved. As they say in legislative bodies, it would perhaps be best to "refer the whole matter back to the committee for further study."

PHILIP G. WRIGHT.

HARVARD UNIVERSITY.

1 'Thus, in fitting an empirical curve to observation it is all important to make a suitable choice of that curve, that is, to determine whether it should be algebraic, exponential, trigonometric, etc." — On Systematic Curve Fitting, Part II. Biometrica, vol. ii, p. 16.

TWO BIOGRAPHIES OF INVENTORS: DICKINSON'S LIFE OF FULTON AND MORSE'S LETTERS OF MORSE 1

THESE books deserve the attention of economists for the same reason as the life of Edison recently reviewed in these columns.2 The biographies of inventors throw light upon the instinct of contrivance, and on the psychological problems connected with it, as well as upon the course of economic development.

There is a curious similarity between the careers of Morse and of Fulton. Both began as painters, and gave promise of at least respectable achievement in the field of art. Both gave up the artist's profession in middle life, and turned deliberately and successfully to the perfecting of mechanical contrivances. Both spent much time in Europe, and there came into contact with distinguished persons of various kinds, evidently making a marked impression on all whom they met. Each is associated with one famous advance in the arts, Fulton with the steamboat, Morse with the telegraph.

Both biographies contain interesting and novel matter. Tho neither is the first for its subject, neither fails to add substantially to our knowledge. Mr. Dickinson's Life of Fulton is based largely upon documentary evidence, and quotes freely from Fulton's letters and memoranda. On the technical side it seems to be excellently done. Mr. E. S. Morse's Life of his father is a larger and in some ways more ambitious book, giving a full picture of a most remarkable personality. The first volume follows that part of Morse's career in which he was a painter, and a painter of distinctly more promise than seems ever to have been the case with Fulton. The second volume deals with his later years, when

1 H. W. Dickinson, Robert Fulton, Engineer and Artist; his Life and Works. London and New York, John Lane, 1913.

Samuel F. B. Morse, His Letters and Journals, edited by E. L. Morse, 2 vols. Boston, Houghton Mifflin Co., 1914.

2 Vol. xxvi. p. 776 (August, 1912).

he was absorbed in the telegraph. It is difficult to conceive anything more extraordinary than the complete change that took place in his interests and ideals. The refusal of a congressional committee to give him a commission for painting a panel in the rotunda at Washington seems to have completely crushed his ambition as a painter. He turned at once to the development of the telegraph, for which the essential device had long been in his mind. Morse's letters, as published in these volumes, give accounts of his European experiences as a painter, and of similar experiences in later life when the telegraph had made him famous. They are interesting quite apart from the aspects which concern the economist.

Fulton shows all the characteristics of the born inventor. Tho not fairly bubbling over with new contrivances, like Watt, Cartwright, Ericsson, and Edison, he gave attention to a number of inventions and experimented all his life with one or another of them. As a young man he went to England, and there tried to establish his position and earn his living as a painter. But he was interested at the same time in the crowd of schemes and experiments then in vogue in England as well as in the United States. This was the era of canals, and Fulton elaborated a scheme for small canals, with inclined planes, by means of which light canal boats were to be hauled from one level to another; a substitute for locks which illustrates the fertility as well as the impracticability of so much scheming among inventors. He devised an early panorama, which proved profitable in Paris and for some time was his main source of support. He was enthusiastic about a submarine boat, in which he succeeded in enlisting for a while Napoleon's interest. The craft was entirely unmanageable with the motive powers then known, and Napoleon was shrewd enough to let it go after a little examination. Nevertheless, Fulton succeeded so far in frightening the British Admiralty about its possibilities that he was bought off for a handsome sum, and so was enabled to make his way to the United States. After his return to his native country, he gave his attention almost solely to the

steamboat, for which he had already formed the well-known partnership with Livingston. It deserves to be remembered that while in England he saw much of the indefatigable Cartwright, and doubtless got much stimulus from that prolific person.

He

It is clear that the instinct of contrivance was strong in Fulton. But he was far from indifferent to pecuniary considerations. He bargained most persistently with the French and the British about his submarine and his torpedoes. labored assiduously to get a steamboat monopoly on the Hudson for his partnership, and to get similar exclusive privileges on the lower Mississippi and on the Neva (from Petersburg to Kronstadt). Apparently he dropped painting because there was little prospect of good remuneration from it; his work had been chiefly upon portraits and miniatures. His biographer remarks that "it cannot be denied that he never neglected an opportunity for profiting pecuniarily by his inventions." There was doubtless some unconscious inversion of emphasis when he wrote to his friend Joel Barlow about the steamboat, "Although the prospect of personal emolument has been some inducement to me, yet I feel infinitely more pleasure in reflecting on the immense advantage that my country will draw from the invention."

Morse showed in the early part of his career less evidence of the contriving bent than Fulton. Indeed, in this biography little is said of the evidences of mechanical talent and interest during the first period of his life. More material on this aspect of his career is to be found in previous biographies, and more particularly in that of Prime. It was natural enough that among the devices to which he gave attention as a young man was a machine for reproducing statuary. A piece of mechanism for the same purpose, it may be noted by the way, had also long engaged the interest of a more celebrated inventor, James Watt; like other devices, it was experimented with at least a century before being brought into serviceable shape. Morse was also keenly interested in Daguerre's invention. He corresponded with Daguerre, first suggested the possibility of taking photographs of living persons, and for