In 1825, Mr. Ronalds invented a perspective tracing instrument, to facilitate drawing from nature or from plans and elevations, an account of which he published in 1828 in a work entitled, 'Mechanical Perspective.' With this machine he was enabled some years afterwards (in 1835), assisted by Dr. Blair, to procure exact perspective projections taken from given noted stations, of the Celtic remains at Carnac in Brittany. The result of these researches was published by Mr. Ronalds and Dr. Blair in 1836, and was entitled, 'Sketches at Carnac; or, Notes concerning the present state of the Celtic Antiquities in that and some of the adjoining Communes.' In connection with this tracing apparatus, he likewise contrived a hexipod staff used for a support, and which has been much employed for the support of instruments requiring great steadiness, such as telescopes, theodolites, cameras, &c. In the year 1843 he became the first and honorary director of the Kew Observatory, and while occupying this office he supplied the observatory with various new contrivances, for which he received a government reward from the special service fund, and a small pension from the civil list. The most considerable of these contrivances were his atmospheric electrical conductor and its appendages, adopted at the Greenwich, the Madrid, and the Bombay magnetic observatories; his photo-barograph, and two photo-thermographs, adopted at the Radcliff observatory, Oxford; his photo-electrograph, and three photo-magneto-graphs. Besides the writings above-mentioned, Mr. Ronalds is the author of an article in the Philosophical Magazine of 1814, entitled, 'On Electro-galvanic Agency, employed as a moving power, with descriptions of a Galvanic Clock;' and other articles in the same journal, detailing his original experiments to illustrate the relations of quantity and intensity in the electric pile. He also wrote four Reports on the Kew observatory, which were fully illustrated and printed in the reports of the British Association for the years 1845-50-51 and 52; and one paper in the Philosophical Transactions on 'Photographic Self-registering Meteorological and Magnetical Instruments,' written in 1846 and printed in the year following. In 1856 Mr. Ronalds published in French, at Paris, a summary of these reports, with some additions, entitled, 'Descriptions de quelques Instruments Meteorologiques et Magnetiques,' intended to explain his instruments at the French exhibition.
Mr. Ronalds is now (April 1864) residing at Battle in Sussex, and during the latter years of life has spent much time and part of his small pension, in collecting and collating an electric library, which might be conveniently available for the advancement of his favourite science, and prove worthy of presentation or bequest to some British public institution, so as to form the nucleus of one which might approximate possibly to a complete electrical library.—From particulars derived from authentic sources.
COUNT RUMFORD (SIR BENJAMIN THOMPSON), LL.D., V.P.R.S.,
MEMBER OF THE ROYAL INSTITUTE OF FRANCE, ETC.
Born March 26, 1753. Died Aug. 21, 1814.
Benjamin Thompson, the founder of the Royal Institution, and more generally known by the title of Count Rumford, which he afterwards acquired, was born at Woburn in Massachussets. His ancestors appear to have been among the earliest colonists of this district, and in all probability came originally from England.
Thompson's father died while his son was a mere infant, and two or three years afterwards his mother married a second husband, Josiah Pierce, also a resident at Woburn. As soon as young Thompson was able to learn his letters he was sent to the school of his native town, kept by a Mr. John Fowle, where he remained until his eleventh year, when he joined the school of a Mr. Hill at Medford. Here Thompson made such advances in mathematics and astronomy as to be able to calculate eclipses. At the age of thirteen he was bound apprentice to Mr. John Appleby, a respectable merchant in Salem, the second town in point of size in Massachussets. His occupations with Mr. Appleby were principally those of a clerk in the counting house, but he appears to have had sufficient leisure to extend his reading in scientific subjects, and also to indulge a taste, he began to exhibit, for designing and engraving. At this time he was likewise occupied with a contrivance for solving the famous problem of perpetual motion, but was ultimately made to see the fallacy of his expectations, by the arguments of an old friend and schoolfellow, Loammi Baldwin, who induced him to attempt-something more practicable though less magnificent.
At this period, 1767, the differences between Great Britain and her American colonies were beginning to assume a serious aspect, and there ensued such a stagnation of trade at Salem and other towns, that Mr. Appleby, having no further occasion for the services of a clerk, was glad to give up to young Thompson his indentures, and allow him to return to Woburn. For the next two or three years Thompson's course of life seems to have been wavering and undecided. At one time he appears to have had thoughts of entering the medical profession, for he remained during some months under the tuition of Dr. Hay, a physician in Woburn, and entered zealously upon the study of anatomy and physiology.