Transcript

of

Obituary Notice: Jonathan N. Hearder, D.Sc., Ph.D., F.R.S.

Transactions of the Devonshire Association. Vol. IX, Part 2, (1877), pp. 55-60.

by

The Rev. W. Harpley, M.A., Hon. Secretary of the Association.

Prepared by Michael Steer

Jonathan Nash Hearder was an electrical engineer, inventor, and educator. He is best known  for his work in developing alternative experimental procedures for use by the blind and vision impaired, and for his early innovation in the field of induction coils. He was well known as a popular lecturer throughout the west of England. Though nearly blind, owing to an accident when experimenting in his youth with a fulminating compound, he acquired a thorough knowledge of practical chemistry and electricity, and was for many years intimately associated with Sir William Snow Harris in his researches. Hearder devised several improvements in connection with the induction coil and the application of electricity to medical purposes. He also invented and patented a sub-oceanic cable, that proved to be almost identical with that subsequently chosen for transatlantic telegraphy. Another invention was a thermometer for lead soundings at sea which should indicate the depth of water by its pressure. Hearder's attainments, however, were not exclusively scientific, and his success as a lecturer was due not only to his knowledge of facts, but to his skill as an experimenter and his genial manner. He took a special interest in the Plymouth Institution, and had an excellent knowledge of local antiquities and history. He acted for many years as electrician to the South Devon Hospital. Hearder died in Plymouth of a paralytic attack on 16 July 1876. The article, from a copy of a rare and much sought-after journal can be downloaded from the Internet Archive. Google has sponsored the digitisation of books from several libraries. These books, on which copyright has expired, are available for free educational and research use, both as individual books and as full collections to aid researchers..

Jonathan N. Hearder, D.Sc., Ph.D., F.C.S., whose death was briefly announced to the meeting last year, was a talented member of a long-settled Plymouth family. He was born in 1810, and from his youth up was an ardent lover of science. Nurtured in comparatively humble circumstances, he enjoyed none of those outward advantages which sometimes smooth the pathway to renown. His father gave him a good middle-class education, but never taught him any business. While yet but a boy, he began the career of a schoolmaster, and continued it for some years, devoting all his leisure time to science, which he was the first in Plymouth to introduce amongst school studies. His researches in science, especially in connection with electricity and chemistry, were both extensive and profound, and made his name well known among the leading physicists, not only of England, but throughout Europe and America.

At the age of sixteen he gave his first course of public lectures at the Mechanics' Institute, at Plymouth, where he showed an electric telegraph he had himself invented, and illuminated words at the farther end of the room. During the two following years he repeated his lectures at Devonport, Exeter, Newton, and Kingsbridge, with apparatus all of his own construction. About this time he became acquainted with the late Sir W. Snow Harris, then Mr. Harris, with whom he was for many years associated in scientific investigations; and he entered the field as the champion of Mr. Harris's lightning conductors, and invented several apparatus and devised many new experiments to prove their utility. At nineteen he had the pride and satisfaction of defeating Lieut. Green, one of the most powerful opponents of lightning conductors, in a long controversy in one of the Devonport papers. Between nineteen and twenty-three he made some interesting discoveries in voltaic electricity, which he and Mr. Harris repeated together ; and the results formed the subjects of many interesting papers communicated by the latter to the Transactions of the Royal Societies of England and Scotland. An accident now befell him which, in the case of a less determined lover of knowledge, would have put an end to everything in the way of research. While engaged in investigating the nature of explosive compounds, having previously invented an apparatus by which gunpowder could be made red hot without exploding, he was deprived of sight by an explosion of fulminating silver. Yet his greatest discoveries were made and his chief honours won after that event. The loss of sight acted prejudicially upon his school, for although he immediately employed competent assistants, yet people thought sight was absolutely necessary to teaching ; so the school fell off, and he was left with the most scanty means of subsistence.

Mr. Hearder now took to music as a profession, having been always musical, but found that he had begun too late ever to excel ; and his father dying about this time, he succeeded to the latter's business, which however he gradually much extended, adding to it the manufacture of stoves, electrical engineering, &c. Many years later, in 1863, Mr. Hearder expresses himself, in a letter addressed to a friend, in these words: "Through all my struggles science has always served to keep my thoughts from myself, and I have learnt now to be so perfectly reconciled to my condition, that I would not exchange ears for eyes. I don't know how I may feel with regard to the singular number, but as there is no prospect of that I never bother myself about it; the fact is I see with fifty pairs of eyes, whilst you and others only see with one pair, and get your impressions from them alone ; and, I daresay, if we were both to go and witness any great undertaking, I should come back pretty nearly as well informed about the matter as you would; and the chances are, that I might have seen something with somebody else's eyes that you would not have observed. Don't mistake me, however, I am not going to brag of my condition; I am quite happy and content in it, and if I have a wish at all for sight, it would be just for the sake of seeing the faces of my children. I cannot help feeling however that the possession of it would enable me to be more useful in the world than I am."

Among the results of Mr. Hoarder's labours may be mentioned the following: Early suggestions for an electric telegraph; an improvement in the construction of the electrical machine; a new form of thermo-electrometer, by which, as long ago as 1828, he worked out the first correct table of the conducting power of metals for voltaic electricity, and discovered some phenomena which were then unknown, and continued to be so until he published them thirty years afterwards. For this he was awarded the bronze medal of the Royal Cornwall Polytechnic Society. A battery discharger for operating with electrical batteries with safety in the dark; a magnetometer for investigating all the relations between the power of voltaic arrangements, the resistance of wires, and the development of magnetism in iron. This gained for him the silver medal; and the same mark of honour was bestowed for a new cast-iron magnet of enormous power - the first attempt to use cast iron for this purpose ; for a new form of electro-magnetic engine ; a new voltaic battery for the electric light, suited for military purposes ; and for a new medical galvanic machine, afterwards adopted as a standard by the medical profession in London. To these must be added a director for applying electricity to the drowned, by which more than one case of resuscitation has been accomplished; and an electro statiscope for discovering the electrical condition of the different rooms of a building whilst electrical experiments are being performed in any one of them, thus bearing upon a disputed point in the action of lightning conductors ; viz., the lateral explosion. In 1855 he invented a modification of the inductive coil, of enormous power. The Abbé Moigno, of Paris, visited him expressly to see this instrument, and the silver medal of the Royal Cornwall Polytechnic Society was again awarded him. In connection with this instrument he invented an instrument which he termed a Spark Counter, for establishing a link of connection between voltaic and magneto electricity, and Franklinic or static electricity.

Mr. Hearder was one of the earliest to perceive that a telegraph cable across the Atlantic was not only important, but practicable, and he was appealed to by the Atlantic Company when in difficulties about their cable. He contrived a plan for obviating the effects of induction, for which he took out a patent ; and his cable, with a slight modification, was ultimately adopted for Atlantic telegraphing. For this he received the silver medal from the Royal Cornwall Polytechnic Society.

In 1862 he invented a deep-sea pressure gauge for sounding by vertical pressure instead of with the line, which is very seldom to be depended upon on account of the interference of currents. In the following years he improved it, and invented, as an accompaniment to it, a deep-sea metallic thermometer, to ascertain the temperatures at various depths, this being necessary in order to eliminate from the result of pressure what is due to alterations of volume by temperature. The Royal Cornwall Polytechnic Society again awarded their silver medal.

Mr. Hearder was one of the most popular lecturers in the West of England. He had a marvellous memory, and was never at a loss for a fact or a date. More popular, more ready, and more successful he could not have been had he remained in full possession of his sight. One of the oldest members of the Plymouth Institution, whilst his health permitted he was most regular in his attendance at the lectures, and one of the most frequent participators in the discussions, dealing with almost every possible topic. As illustrative of his industry and great mental activity, the following list of lectures, which he gave at the Athenaeum, Plymouth, may be adduced :

1833. Divisibility of Matter. 1834. Gaseous Combustion. 1836. The Atmosphere. 1840. Arnott's Stoves. 1842. Electricity. 1843. Electricity; and Electricity - Lateral Discharge. 1844. Electro-Magnetism as a moving power, two lectures. 1845. Electro-Magnetism, in two lectures; Magneto-motive Mechanics; and Combustion. 1846. Some Recent Discoveries in Science. 1847. Magnetism; Galvanism. 1848. Gutta Percha and its Applications. 1849. Electro-Physiology. 1850. The Electric Light; Atmospheric Electricity, in two lectures. 1852. Combustion; and on the probable connection between the Earthquake notice^ in this country in August last, the Movement in the "West Indies and Egypt, and an Eruption of Etna. 1853. Recent Earthquakes. 1854. The Electric Telegraph. 1855. Electricity. 1856. The Induction Coil; and some new Thermal and Statical Effects of the Induction Coil 1858. Water; and Telegraph Cables.

1859. On an improved form of Submarine Telegraph Cables; and on the Physical Properties of the Atmosphere, two lectures.

1860. The Inductometer. 1861. Rifled Ordnance; and Domestic Economy of Fuel 1863. Gas as a Fuel; and a new Deep-sea Pressure Guage. 1863. Earthquakes. 1864. The Electric Light 1865. The Physical Properties of the Atmosphere. 1866. On the Metal Magnesium, experimentally illustrated; The Atlantic Telegraph; and Electro-Magnetism. 1868. Voltaic Electricity; a Review of Professor Tyndall's recent investigations concerning Sensitive Flames; and Electro-Magnetism. 1869. Recent Earthquakes and Volcanic Eruptions. 1870. Degeneration of our Deep-sea Fiaheriea 1871. Aurora Borealis. 1872. Early Electro-Therapeutics.

Mr. Hearder was a zealous lover of all matters connected with local antiquities and history; and in his younger days was actively associated with his now long-deceased brother, Mr. George Hearder, in the production of the very interesting and successful local periodical - The South Devon Museum. The bent of his mind was quite as practical as it was investigative. He not only contrived medical electrical apparatus, but practised as a medical electrician, and was electrician to the South Devon Hospital. He was a Fellow of the Chemical and a member of various other scientific societies. He was one of the small number who assisted in the formation of this Association ; he frequently attended its earlier meetings, participated in the discussions on the various papers read, and contributed several papers himself. These, which are to be found in the pages of the Transactions of the Association, bear the following titles :

"Imperfections in the Mode of Fitting Lightning Conductors, read at Plymouth, 1863. A Mode of Preserving the Iron-Plating of Ships from the Corrosive Action of Sea Water," read at Torquay, 1864.

"Some Remarks on the Cost of the Light from Magnesium, as compared with other sources of Illumination : with an Account of some new Inflammable and Explosive Compounds of Magnesium ;" and, "An Account of some Experiments made with the Electric Light," both read at Tiverton, 1865.

"Experiments to Determine the Rate of Magnetic Developments in Iron, whilst under the Action of Electrical Currents, with some Practical Inferences deducible therefrom," read at Tavistock, 1866.

"On the Fulgurator: a New Apparatus for producing Sparks of very great length;" and, "On the Degeneration of our Sea Fisheries," read at Devonport, 1870.

"On the Progress of Electro-Therapeutics, with a description of Galvanic Instruments invented by the Author," read at Exeter, 1872.

On Wednesday, July 12th, 1876, Mr. Hearder was attacked by paralysis; and on the following Sunday, although it had been hoped that all danger was over, he died. Always genial and hearty, ready alike to learn and to impart, never tiring in the pursuit of knowledge, and ever seeking to bring the speculative within the domain of the practical, his death created a blank in the literary and scientific circles of Plymouth, which it would be difficult to fill. With him departed almost the last of that able band of men who, forty years ago, made the name of Plymouth famous in scientific and literary matters, and among whose members are to be found the honoured names of Henry Woollcombe, John Prideaux, William Jacobson, Colonel Hamilton Smith, Sir William Snow Harris, George Wightwick, Samuel Rowe, Dr. Cookworthy, and Jonathan Hoarder.