Background
Cavallo was born on March 30, 1749, at Naples, Italy, where his father was a physician.
1790
Cavallo, National Portrait Gallery, London
philosopher physician scientist
Cavallo was born on March 30, 1749, at Naples, Italy, where his father was a physician.
Nothing is known of Cavallo's education.
Cavallo did his scientific work in England, where he settled in 1771 intending to acquire some experience in business. He apparently put aside his plans on becoming acquainted with some amateur English physicists, particularly William Henley, who introduced him to experimental philosophy and encouraged him in its pursuit. He became a fellow of the Royal Society in 1779.
Cavallo’s first studies (1775-1776) concerned atmospheric electricity, which he explored with Franklin kites and with improved detectors of his own invention, fashioned after Canton’s pith-ball electroscope. Although little came of his investigations, they required a course of self-instruction that culminated in Cavallo’s most important work, A Complete Treatise on Electricity in Theory and Practice (1777). A second edition, with revisions, appeared in 1782 and a third, in three volumes, between 1786 and 1795. An excellent compendium, the Treatise served the needs of both the neophyte and the initiate, who found in its appendixes valuable details about medical electricity; about Beccaria’s obscure theories; and about Cavallo’s forte, the design and operation of electrostatic instruments.
With the publication of the Complete Treatise Cavallo switched his attention to the physics of the atmosphere and to the constitution of “permanently elastic fluids.” Again his strengths appeared in instrumentation - an improved air pump and a modified eudiometer - and in smoothing the way for others. This time his course of self-instruction, A Treatise on the Nature and Properties of Air and Other Permanently Elastic Fluids (1781), was a judicious examination of contemporary work, particularly Priestley’s. He always retained a lively interest in pneumatic physics and chemistry, whose applications to ballooning and to medicine became subjects of two later books. Cavallo also gave some attention to magnetism, on which he delivered a Bakerian lecture to the Royal Society in 1786 and published a treatise the following year; and he had a sustained interest in music - he was an amateur violinist - which led him to an investigation of the temperament of fretted instruments (1788). The inevitable text on the physics of music appeared in Cavallo’s last, most ambitious, and least successful exposition: his wordy, overly elementary Elements of Natural Philosophy (1803).