Chapter 1: The Mallet Family

Only three families can trace their descent in the male line from the Norman conquerors, i.e. those who fought at Hastings in 1066. One of these is Malet (or Mallet). In 1661, a branch of the Mallet family  living at Ash near Iddesleigh in Devon claimed to be the senior branch of the ancient house, the estate at Ash being sold in 1881, the year in which Robert Mallet died. Two members of the family of John and Jane Mallet (descended from the Mallets of Ash) emigrated to Dublin, Richard and Robert, who I will refer to as Robert Snr. Robert Snr. was the first to arrive and set up business as a cabinetmaker at 62 Capel Street.

In 1782, at the age of 23, Robert Snr. married Anne, the daughter of William Pike. When Pike died in 1801, Robert Snr. took over his father-in-law’s plumbing and sanitary business located at 16 Ship Street. Richard Mallet had also married, and one of his sons, John (born in Devon in 1780) had emigrated to Dublin at the invitation of his uncle Robert, and married Robert’s daughter, Thomasina Mallet. John later encouraged his father and mother to join the other members of the family in Dublin, and to bring with them their two remaining children, Jane and William. William had an inventive bent and a number of his devices were manufactured in his uncle’s foundry.

Robert Snr died in 1804 and his nephew John took over, subsequently moving to work and live at newly erected premises at 7.8 & 9 Ryder’s Row, a lane way running between Capel Street and Parnell Street.

Building on Ryder’s Lane (later Row) had begun in the 1750’s/ John continued to build and expand the business, and took an active part in the municipal affairs of the city. Thus, by 1820, Watson’s Gentlemen’s and Citizen’s Almanack could report that ‘Mallet, J. (was a) Plumber, Hydraulic Engine Maker and Iron Founder’, indicating a trend towards general engineering work, a trend later capitalised upon by his son Robert, who joined the business in 1831.

Robert Mallet was born at Ryder’s Row on the 3rd June, 1810, and was at first a weakling child. As he grew, however he developed a strong constitution and considerable powers of endurance.

Chapter 2: Early Education

Mallet, a Protestant, received his early education at Bective House in Dublin. At the time that Mallet attended school the Bective House Seminary for Young Gentlemen was located at 2 Great Denmark Street. The building now forms part of Barry’s Hotel and is still largely unaltered externally. The principal and owner of the school was the Rev. George Newenham Wright. Wright, the son of a doctor was born in London in 1793, and graduated from Trinity College, Dublin in 1814. Oradined priest in 1818, he held several curacies in Ireland before eventually moving to England, where he was appointed reader of St. Mary Woolnoth in London, and later became master of the Tewkesbury Grammar School. Mallet remained at Bective House until he was nearly sixteen. In 1836, the young Mallet described the deficiencies in the manufacture of pipes, steam engines, etc., in France and exhibited a great enthusiasm for engineering matters.

Mallet had acquired a good grounding in French, and appears to have had a reasonable acquaintance with the German language. During all this time he paid particular attention to engineering matters, but he was equally fond of chemistry, in which he attained marked proficiency at a very early age. When a little over 12 years old he used so much of his time in making all sorts of curious boyish experiments and chemical mixtures, often of anything but a pleasant character, that a small room was set apart as his ‘laboratory’. Here at Ryder’s Row he spent a great deal of his time when not at school, and he was fortunate in being able to secure everything he required for the construction of experimental apparatus from his father’s works nearby.

So much was this little room his favourite haunt that it was said that whenever it became the stern parent’s duty to correct the boy for mischievous pranks, the punishment that was found most severe was to lock up his ‘laboratory’ for from one to three days, according to the nature of the offence. This laboratory was afterwards provided with ever requisite for chemical and metallurgical investigation, and good use was made of it long before its owner was twenty-five years old.

Having successfully completed the entrance examinations in Greek and Latin, Mallet entered Trinity College, Dublin as a ‘sociorum commensalis’ on 4th December, 1826.Terms at that time we kept by answering at the examinations held at the beginning of each term. To take the BA degree, a student was required to keep at least 11 terms.

Besides the private lectures given by the tutors in their own chambers in the Science and Latin of the term, students attended the Public Lectures delivered by the College lecturers, the morning lecture of the Science of the term being held every morning immediately after Chapel.

Mallet’s academic record was not outstanding, indeed he became within a hair’s breadth of being cautioned in the Hilary term of his final year. As an essentially practical young man, academic life must have seemed somewhat tedious to him and this is borne out in his examination records. During his time at College, Mallet received Mathematical instruction from a Mr. Friedlezius, a Swedish Professor of Mathematics. This special training in Mathematics must have been of the greatest use to him, not only as an engineer, but as one of the earliest seismologists.

Mallet received his BA degree at the July Commencements of 1830. (The Engineering degree courses did not commence in TCD until 1842). After he left College, Mallet spent much of his time in his father’s works at Ryder’s Row and also took every opportunity to visit engineering establishments in England. He also found time to take instruction in surveying and levelling from Joseph Byrne, a Land Surveyor and Valuer with a practice at 23 Lower Mount Street in Dublin.

The rapidity with which Mallet acquired practical engineering knowledge was remarkable and was due to a combination of the education he received at Trinity College, practical experiments in his father’s works, and guidance from a relative, Dr. Burton, a well travelled man of considerable accomplishments.

Chapter 3: The Young Engineer

In 1831, Mallet made an extended tour of the Continent in the Company of Benjamin Purser of Rathmines Castle and Professor Friedlezius, which included a visit to the Mer de Glace, observations of which lead him to present a paper to the British Association meeting in 1837 on glacier mechanisms.

On his return he joined his father’s business and rapidly assumed responsibility for the Victoria foundry and its attached fitting and machining shops. The principal work carried on by the firs as the time was brass and copper founding and plumbing of all kinds.

The fact that his father devoted so much of his time to Corporation affairs (he was a High Sheriff of the City of Dublin 1831-32 and served on many committees) may account for his taking over the conduct of his father’s works so rapidly.

The early 1830’s saw the dawning of the railway era and the decision to set up an Irish Board for Public Works (1831) under the Chairmanship of Colonel (later Field Marshal Sir) John Fox Burgoyne. These events contributed in no small way to the increase in engineering activity in Ireland (including the setting up in 1835 of a Society of Civil Engineers, based in the Customs House, with Burgoyne as its first President).

Burgoyne was not enamoured with that he saw and his letters paint a sorry picture; in fact his first impression of Ireland was hearing the wailing of the women as they bade farewell to their husbands incarcerated in a convict ship at Kingstown Harbour preparing to set sail for Australia.

Investment in public works and railways began with the improvement of the River Shannon navigation and the building of Ireland’s first railway, the Dublin-Kingstown. As history relates, this did not improve the lot of the general populace, and, furthermore, left many businesses, such as Mallet’s own firm, without a future when the ‘honeymoon’ period ended in the late 1860’s.

In his presidential address to the Institution of Civil Engineers of Ireland in 1866, Mallet had some harsh things to say about the British Government’s laissez-faire policy if administration following the 1846-7 famine, and stated publicly that he thought it had been a disastrous policy and had reduced the functions of the Board of Works to a mere nothing and severely reduced the avenues of employment open to engineers in Ireland.

Returning to the domestic front, Robert continued to live at Ryder’s Row after his marriage in November 1831 to Cordelia Watson.

Cordelia came from a distinguished Dublin family, who were for generations engaged in the bookselling business. Robert had known Cordelia for many years and travelled with her brother of his first visit to the Continent. On his son’s marriage, John Mallet first went to live across the road at 97 Capel Street before moving to 5 Drumcondra Terrace, although still keeping a business address in Capel Street. Around 1832 Robert became a full partner in the firm, which now traded as J. & R. Mallet, sometimes found on Ironwork as I. & R. Mallet. Robert’s brother had died in infancy, but his sister Anne married Benjamin Purser of Rathmines Castle in 1836.

The Victoria foundry in Dublin was greatly extended under Robert’s guidance and secured large contracts for railway plant, permanent way materials, cast-iron bridges, cranes and other ironwork. The engineering work carried out in Ireland between 1830 and 1860 by Mallet’s firm was both extensive and varied and forms the subject of a separate paper, but what brought Mallet into the fill light of the engineering world o his day was undoubtedly his feat of raising, by means of screw jacks, the roof of St. Georges Church in Dublin, thereby enabling the supporting wall to be rebuilt and the roof retained to this day in its original form. This work carried out when Mallet was only 24, earned him a Walker premium from the Institution of Civil Engineers in London in 1842.

Chapter 4: Institutional Involvement

In October, 1833, Robert had been elected a member of the Royal Irish Academy, and in the space of a few years enriched the proceedings of that body with several important papers of metallurgical and geological topics. In addition, he had begun to write on the nature of earthquakes and associated phenomena. His contributions to the Journal of the Geological Society of Dublin, of which Society he was three times President, show a remarkable grasp of the complex nature of crustal and glacial movements, and in 1848 he proposed the general adoption of a new and uniform principal for laying down geological sections.

In 1846, on the first occasion of his election to the Presidency of the Geological Society of Dublin, Mallet had a painstaking approach to the investigation of any matter.

In May, 1839, Mallet was elected an Associate of the Institution of Civil Engineers, proposed by the leading consultant, Sir William Cubitt, and seconded by Thomas Rhodes, the Engineer to the Shannon Commissioners, and Francis Bramah. He had joined the Irish Society of Civil Engineers in 1836 and became a life-long supporter of both professional bodies. Mallet was transferred to the class of Member of the London Institute in 1842 on the recommendation of Burgoyne, William Fairbairn, a leading structural and mechanical engineer, and Vignoles, who, with Sir John Macneil, had laid the basis for the development of the railway system in Ireland.

During the previous year, Mallet, together with Sir Robert Kane, had advocated that a Technical School should be set up in Dublin to provide instruction in engineering subjects. When the Board of Trinity College Dublin realised that this development was likely to be supported, it approved a submission from Dr Humphrey Lloyd, Professor of Natural Philosophy, for founding a School of Engineering within the walls of the College and, in 1842, the creation of the Chair of Civil Engineers, whose first occupant was Sir John Macneil. Mallet also applied for the Chair and asked Macneil for a reference. Macneil declined on the grounds that Mallet’s references from the eminent engineer William Cubitt and James Apjohn, the Professor of Chemistry in TCD were far more suitable that any Macneil himself could offer.

Chapter 5: Mallet the investigator

Mallet presented his first and albeit somewhat unusual contribution to the British Association meeting in Dublin in 1835, the same year that the engineering profession in Ireland formed themselves into a society and the BA set up a separate Mechanical Section. His report was on the application of a series of magnets for the atomic separation of brass and iron borings and filings.

He had also begun an extensive series of investigations into the corrosion of iron. Some idea of the output of his scientific writings amidst all the business of managing the Victoria works may be gained from noting over fifty papers on diverse topics listed by the Royal Society in their Catalogue of Scientific Publications between 1835 and 1858.

Mallet patented a number of devices and techniques during a lifetime of engineering and scientific study. The earliest patent, taken out in 1841, was for methods of protecting metals from corrosion or oxidation and preventing the fouling or iron ships or buoys, a direct application of his research work on corrosion of iron, but probably his most widely applied invention was that for buckled plates, first taken out in 1852. These and other patents are referred to in other papers.

Chapter 6: Residence in Dublin

In or about 1836 Robert, now well established in the engineering business and scientific worlds, moved with his wife Cordelia and their three children to a house know as Delville in Glasnevin, his father John later moving in with them and living there even after his son later moved to Monkstown. The pencil sketch of Delville was executed in November, 1854, by one of Mallet’s daughters, Sarah Constance. Delville was built by Dean Patrick Delaney and his friend Richard Helsham, Professor of Physics and Natural Philosophy at Trinity College Dublin (1682-1738). They were both friends of Swift, who is said to have written Gulliver’s Travels in the Temple, which stood in the garden of Delville. The house was destroyed around 1950, the Temple having previously been pulled down in 1944 in the course of building a roadway to the Bon Secours Hospital.

A first cousin of Robert’s, Sir Frederick William Burton, later to become Director of the National Gallery in London, painted, in 1841, a water colour entitled, ‘The Aran Fisherman’s drowned child’, which now resides in the National Gallery in Dublin. Robert, his wife Cordelia, and their second son, Robert Trefusius are said to have been models for the fisherman, his wife and drowned child.

In the midst of his scientific and engineering careers, in March 1854, Robert suffered the loss of his first wife, Cordelia, she having borne his three sons and three daughters in the space of nine years, a not inconsiderable achievement in those days. The same year he was elected, along with James Apjohn and John Fox Burgoyne, to Fellowship of the Royal Society.

In or around 1858, Robert left Delville and took up residence at 1 Grosvenor Terrance in Monkstown, a suburb of Kingstown. It was certainly nearer to the Holyhead Mail steamers and he was now becoming a frequent traveller between Dublin and London. Delville was rather large, especially as Robert had been left a widower, his family was growing up, all three daughters by then being marries and his three sons were settling into their chosen careers of chemist, engineer and geologist, most appropriate choices considering their father’s interests. It appears that Robert’s father, who died in 1868, remained at Delville for some years under a caretaker agreement, an arrangement which probably resulted from the depressed state if the market for large houses in Dublin at the time.

By 1860, engineering work in Ireland had become scarce. The main railway routes had been substantially completed, drainage operations had ceased, and ironworks had so increased in number and variety in England and Scotland that, after importing iron and coal to Dublin, costs became too high to permit profitable competition with English and Scottish firms, whilst the state of the Irish industry afforded to opportunity for engineering works and very little employment for engineers.

Mallet had fully expected to obtain the contract of the Dublin Corporation for the water pipes and other castings connected with the waterworks, but, unfortunately for the trade of the city and its workmen, the contract went to Scotland. If the Dublin firm had secured this contract, it is not unlikely that J. & R. Mallet would have carried on business for several more years. Around £300 – £400 were paid weekly by the firm in wages to the workmen. Furthermore Robert was by now spending most of his time in London attending to his growing consultancy and his scientific writings, and his father was in his eighties. It was therefore decided to close the Victoria Foundry, the business being placed in the hands of Wheatley, Kirk & Price, a firm of engineering valuers, for eventual winding up.

Chapter 7: London and the Constitution

Having moved permanently to London, Robert lodged, whilst looking for a suitable residence, with a Mrs. Dial, to whose daughter he became attached and subsequently married in 1861.

The house he acquired was Enmore, The Grove, Clapham Road, a substantial property in a then quiet residential part of South London and within easy reach of his consulting offices which were first located at 11 Bridge Street and later at 7 Westminster Chambers, Westminster.

Apart from individual papers, Mallet was a regular contributor to the discussions at meetings of the both the Institutions of Civil Engineers in London and Dublin throughout his professional career.

Environmentalists may be amused by Mallet’s contribution to the discussion on Denton’s paper to the ICE in 1861 in ‘Discharge from Under-Drainage’.

In 1866, Mallet was elected President of the Institution of Civil Engineers of Ireland, having served on the Council and as a Vice-President for many years. He had in fact refused the Presidency the previous year on account of his residence and duties being in London, but was persuaded to change his mind and accept what was regarded as an honour bestowed on him by the Institution in recognition of his achievements. As President he suggested that the Institution should become a chartered body. Mallet was strongly pro-Ireland if not pro-Irish and never passed up an opportunity to pinpoint Ireland’s problems and suggest solutions. He was firmly of the opinion that the then available technology should have been imported and Ireland less dependent on agriculture.

In March, 1859, Mallet delivered an important paper to the ICE on the coefficients of elasticity and rupture in wrought iron, in particular reporting on results obtained from work on mass forging. He was awarded a Telford Medal for the paper, but from the discussion it is clear that not everyone agreed with his conclusions. Clay of the Mersey Steel Co. said that, although the author possessed such eminent qualifications and great practical experience, he had been led to draw erroneous conclusions. George Hemans also disagreed.

Chapter 8: Heavy Ordnance

Mallet had referred in his paper to the experimental work carried out by him in 1856 in connection with the construction of large mortars, and reported that he had declined a further grant to continue the experiments.

This subject of heavy ordnance had occupied Mallet’s thoughts for many a year. As early as 1832, on a visit to the continent, Mallet had witnessed the effects produced at the siege of Antwerp by 24” calibre shells thrown by the French, had observed that causes of their apparent failure and proceeded to investigate the whole question of the relative powers of demolition of shot and shells and relative relationships to calibre and weight. Mallet decided that the minimum diameter of an effective shell in siege conditions should be around 36”. The mortars mostly in use at the time were of 13” calibre (based on the old French standard Paris Foot).

Later, around 1850, he gave far more attention to the problems associated with constructing heavy ordnance. For at least two centuries the advantage of cutting spiral grooves in the inside of barrels of small-arms had been known. Rifling the barrel gave the projected shell a rotation about an axis parallel to that if the gun and increased the range and accuracy of the shots. Experiments with larger bore guns invariably ended with the barrel of the gun bursting and progress was barred by the difficulty of obtaining cannon of sufficient strength to bear charges of power proportionate to the weight of projectile, until the principle of ringed ordnance was communicated by Mallet to a meeting of the Irish Royal Academy on the 25th June, 1855. The principle involved increasing the bursting strength of the mortar by building up the whole thickness using superimposed lamina or rings with initial tension, and could be likened to present day pre-tensioning of structural components. This method later became universally employed in the manufacture of large rifled cannon. The mathematical theory of ringed ordnance was developed by a TCD Professor, Dr. Andrew Searle Harte, who taught the principles of mechanics to engineering students in the 1850’s.

This lengthy paper to the Academy was subsequently published in 1856 in book form by Longmans and formed the basis for most of the later books on ordnance and on casting and founding. In the preface to this book, Mallet expressed the opinion that, though Government factories and foundries are a necessity, the construction of ordnance is essentially a work of mechanical engineering. The book contains information on the resistance of cylinders to internal pressure, the molecular constitution of crystalline bodies, the physical conditions induced in casting and forging, especially on a large scale, the effects of fluid or gaseous pressure, expansion by heat, and numerous questions relating to metallic alloys, the action of repeated strains and the determination of the strength of metals and alloys.

War had broken out in the Crimea in October 1853 and Mallet was keen to proceed with building and testing a monster mortar of 36” calibre in order that similar mortars could be used to break the Russians hold on the fortress town of Sevastpool.

Mallet’s claim to be the prior inventor of ringed ordnance was contested by Capt. T. A. Blakely and the lengthy arguments and counter arguments can be followed in the pages of the RIA Proceedings for 1855. My own impression is that Mallet just about won the day and relied mainly on his reputation as a scientific investigator to silence his critics.

Mallet had laid his original designs before Government in February, 1851, but the ordnance authorities reported decisively against his proposition. While accepting the resulting destructive power of such shells, they did not believe that a mortar could be built to fire them. Dealing with the red tape at the War Office was not something he relished, but fortunately Mallet had the opportunity to express his views personally to the Prince Consort and Lord Palmerston and, with their assistance and encouragement was able to design and have constructed two 36” mortars.

The contract for these mortars was signed in August, 1855, with C. J. Mare, with whom Mallet was to have dealings during the construction of the Westminster Bridge in London. The construction and subsequent trials of these monster mortars may be traced in the Proceedings of the Ordnance Select Committee and in the pages of the Engineer. An engraving depicts the mortars in the Thames Ironworks of C. J. Mare at Blackwall. Their competition was delayed until after the Crimean war was concluded due to Mare becoming bankrupted by the contract for building the foundations of the New Westminster Bridge. By April, 1857, the mortars were in an advanced state of construction and were conveyed down the Thames from Blackwall to the Royal Arsenal at Woolwich and thence conveyed in pieces to the practice ground on Plumstead Marshes. A platform was erected on which the mortars were mounted for firing and on the 19th October, 1857, the Ordnance Select Committee witnessed the firing of seven rounds with varying weights of charge, the greatest range achieved being 2644yds. The spherical mines in some cases penetrated up to 30 feet into the ground. The mortar was damaged and had to be dismantles, and a Sub-Committee was set up to report on the state of the mortar after firing. A further trial was carried out on 18th December and again one of the rings was found to be defective and sent to The Thames Ironworks for repair.

The mortars were placed in the charge of the Principal Military Storekeeper at Woolwich. Some ten years later, the Superintendant of the Royal Carriage Dept., having reported that the bed of Mallet’s mortar in the marshes was in a decayed and unsafe condition, it was decided to destroy it by means of a small charge of gun cotton, and allow the mortar to subside onto the ground. Nine charges failed to shift the mortar, but eventually the staff at Woolwich worked out how to place the charges in order to obtain the desired effect. They probably learnt a lot from Mallet’s mortar even in its death throes.

Working from his office in Westminster, Mallet had in 1855 also designed a floating battery for conveying his mortars to the Crimea, but peace was concluded a few months after the fall of Sevastpool and it was never constructed. Around the same time, Mallet designed a 70 Ton capacity wrought-iron sheer legs for the Victoria Docks then building in London, and considered to be the best docks in the world at the time. Sheer legs were employed in the dockyards for masting and demisting ships in addition to lifting heavy weights. They were erected by the assignees of the late firm of C. J. Mare under the direction of George Bidder, Engineer-In-Chief to the Dock Company. The legs were formed of hollow tubes of boiler plate riveted together, each tube having the form of a parabolic spindle.

Chapter 9: Writings of Properties of Iron

Mallet continued to look after his patents, in particular the patent rights for buckled plates, invented in 1852, and used widely for many years, particularly as a strong and economic method of flooring major road bridges.

With his iron founding experience, he attempted to push forward his ideas on the structure of wrought and cast iron on a scientific basis based on observation and experimentation and came in for some criticism by later commentators.

In Todhunter & Pearson’s extensive ‘History of Elasticity and Strength of Materials’, published in 1893, three of Mallet’s contributions to the subject are critically reviewed. Reviewing his 1856 paper on the increased deflection of girders or bridges exposed to the transverse strain of a rapidly moving load, Mallet’s conclusions were described as ‘erroneous’.

Mallet laid considerable store by his law relating to the molecular aggregation of crystalline solids. Using his law, Mallet inferred that, where there existed a sharp change of surface contour, a plane existed in the neighbourhood of change in which there was confused crystallisation. This he called the plan of weakness. Todhunter, however, considered that this weakness was more likely due to initial stress imposed by the cooling rather than to any change in the attitude of the crystals.

It seems from our present day knowledge of the strength and properties of materials that much of what Mallet contended was not far from the truth and that he tended to be faulted, not for her observational and experimental techniques and subsequent empirical conclusions, but rather for his lack of a strict analytical approach to problems.

Chapter 10: International exhibitions

Whilst carrying out his consulting practice he devoted an increasingly greater amount of his time to writing. At all times a most prolific contributor to engineering and technical papers, he was, because of his great gift of clear description and concise summary employed by the Government and others to prepare reports.  During his association with the Practical Mechanics Journal, (he was editor from 1861 to 1867) he edited the ‘Record of International Exhibition, 1862’ and contributed to it a masterly introduction which is a history of exhibitions from the earliest times up to 1862, and the interesting and suggestive article ‘Retrospect – the Future.’ In section G9 at the Exhibition, Mallet had traced the history of machine tools and suggested a method of classifying them by function. In the same year, Mallet was honoured by TCD at the Winter Commencements with the honorary degree of Master of Engineering (MAI), along with Richard Griffith, John Macneil and Samuel Downing. Two years later, Trinity bestowed on him an honorary LL.D. During his association with the Practical Mechanics Journal, Mallet published a series of major articles on iron founding and ordnance.

Mallet went to Paris in April 1867 to report for the journal The Engineer on the French International Exhibition. He found that the French had made great strides since the 1851 London Exhibition, but English Exhibitors represented only about 5% of industrial strength. Having been officially opened inauspiciously on April Fool’s Day, there were considerable delays in mounting many of the exhibits.

Mallet warned Britain not to fall behind Europe and America in the matters of technological innovation and education lest ‘the tortoise beat the hare at last.’

Mallet, writing to Joseph Holmes from 7 Westminster Chambers on 2nd August, 1867, on his return from Belfast, complains of being overburdened with work.

Mallet’s reports on ‘The Artillery and other war material produced at the International Exhibition, Paris’  were reproduced as a series of twenty-four substantial articles, and represent and invaluable source of information for the military historian.

Another diversion which Mallet became involved with at the Dublin exhibition of 1865 and Paris of 1867 was that of acting on Committees to adjudge competitions to find a burglar-proof safe at a time when robberies were very prevalent. These ‘Battles of the Safes’ as they were styled attracted great attention from the business community and were prone to all manner of partisan wheelings and dealings. It is amusing to read the accounts of the intense rivalry between, for instance, Chatwood of Britain and Herring of America. There are illustrations giving some idea of the atmosphere surrounding these events, in some cases apparently biased in favour of Britain, as seen through the eyes of a London publisher.

Chapter 11: Mallet the editor

Continuing his outpouring of useful scientific commentaries, between 1867 and 1870, Mallet revised or added notes to a number of texts on subjects close to his heart. Writing with authority, based on his years of practical experience, Mallet’s primary objective was to bring the texts up-to-date with the rapidly changing practices of the day, but he could not resist the temptation to being biased in favour of his own investigations and patents, particularly in the notes added by him as an appendix to Law’s ‘Civil Engineering’, published in 1869. In these notes, he defends his own improvements to the atmospheric railway system, lateral transferring of carriages from rail to road, and improvements to graving docks, the latter two being the subject of patents taken out by Mallet. He took issue with Law on the matter of the corrosion of iron in sea-water and referred readers to the four reports to the British Association of his extensive investigations carried out in Dublin in the 1830’s.

Mallet’s close association with the War Office and military engineering is reflected by his honorary membership of the Royal Artillery and United Services Institutions, and his being asked to translate a memoir by Baron von Weber, entitled ‘Our Railway System viewed in reference to invasion’. As the original memoir was only some 40 pages, Mallet’s ‘introduction’ of some 60 pages may be regarded as a significant contribution to the subject. Von Weber was a celebrated and respected railway engineer who had handled the complicated and difficult arrangements for the movements by railway of nearly the whole of the armies of the South German Kingdoms. The main principle enunciated for preparing the railway systems for the rapid movement of large numbers of troops and equipment was standardisation of rolling stock and operational procedures. Mallet dedicated the book to Burgoyne.

Field Marshal Sir John Fox Burgoyne, who, was Chairman of the Irish Board of Works, had founded the Society of Civil Engineers of Ireland, died an old man the following month. Mallet had, a few years earlier, contributed to the latest edition of a small work on Macadamised Roads, the third part having been written by Burgoyne prior to 1845.

The fourth edition of a treatise on Bricks and Tiles, written by Dobson, was published in 1868, with chapters added by Mallet on the latest brick making machinery and the general science of brick-making. Mallet noted that quite a trade in coloured bricks was waiting to be opened up for both external and internal decorative building and instanced the Romanesque domes on the interior of the great central hall of the Museum Building in TCD, in which ordinary bricks are enamelled in brilliant glazed colours, arranged in designs, upon the exposed face only.

In 1870, Mallet considerably revised and rewrote a text by George Field on Colours and Colouring, the chapters on the Theory of natural Colours and Oils, Dryers & Varnishes being written wholly by him. In the latter case, Mallet refers his readers for more information back to his original researches  carried out in the 1840’s for the British Association.

The series of articles by Mallet on the practice of iron founding witch appeared in the Practical Mechanics Magazine Between Dec. 1865 and March 1867, together with the articles in the Engineer on related topics and his extensive writings on ordnance over a long period, combine to form a form a library output indicating that Robert Mallet was a mechanical engineer in the widest sense and a metallurgist in the narrower sense, with a specific interest in the application of engineering science to the development of ordnance.

Mallet’s desire to bring the scientific and technical advancements of other countries to the attention of English readers is well illustrated by noting his translation of Professor Palmieri’s treatise on the 1872 Eruption of Vesuvius, Mallet used as a frontispiece a quotation from Goethe’s “Kunst und Alterthum”-
‘the Translator should look upon himself as a Merchant in the Intellectual Exchange of the world, whose business it is to promote the interchange of the produce of the mind.’

In his introductory sketch of 78 pages (the original work only ran to 57 pages!), Mallet described the present position of terrestrial vulcanicity, and traced the outlines and relations of the two branches of scientific investigation-vulcanology and seismology. The preparation, with his son prof. J.W. Mallet of the University of Virginia, of an earthquake map of the World had  ‘demanded visits to the chief libraries of Europe and the collating of some thousands of authors in various languages and of all time, and was a work of great and sustained labour.’

Mallet ended his introduction with these words:
‘To the popular mind, Volcanoes and Earthquakes are only isolated items of curiosity amongst “the wonders of the world” – few geologists even appear to realise how great and important are the relations of vulcanicity to their science, viewed as a whole. Yet of vulcanicity it is not too much to say, that in proportion as its nature and doctrines come to be known and understood as parts of the cosmos, the nearer will it be seen to lie at the basis of all Physical Geology.’

Chapter 12: The final years/ Assessment of the man

After a life of unusually sound health and active occupation, in the Winter of 1871-72 his eyes suffered from a severe attack, which gradually impaired and, after some time, practically destroyed his sight for all other purposes than merely guiding his movements, although he continued to accomplish much mental work with the aid of an amanuensis. In November, 1880 he was attacked by diffuse cystitis and, after a year of much pain, patiently and courageously borne, with continuous confinement to bed, he died peacefully on the 6th November, 1881, 69 and was laid to rest in Norwood Cemetery near his home in South London.

Mallet had a most remarkable capacity for at once perceiving the essential elements of any set of problems placed before him, or the fundamental principles upon which any question depended.

Previous identical experience was not at all necessary to him. The law involved its application were the first and immediately succeeding thoughts upon the presentation of any question or project.

Owing to this capacity he was enabled, as shown in many of his papers, to state and elucidate a question or subject in the clearest manner.

He possessed extraordinary inductive powers, and his generalisations proved themselves to be very accurate. Of his store of knowledge upon almost every scientific subject, none but those who knew him, and enjoyed his intimate acquaintance, could form an adequate conception.

An ordinary man might well have been satisfied to show such a record of successful practical work, but the contemplation of Mallet’s literary labour, largely achieved in his spare time, and assisted by his excellent knowledge of continental languages, suggests the reflection that as a writer alone he claims the abundant recognition of the profession. It is perhaps rather in this capacity, and as a man of science, than as a skilful and original engineer, that his reputation is founded.

In social and private file, Mallet was beloved for the kindness, geniality and humour of his disposition, for his readiness in conversation, and for his uniform good temper.

Robert Mallet was, in scientific thought, remarkable for the originality of his ideas  and was, as Dr. Gladstone said in his life of Faraday, ‘an intellectual chieftain who could meet the prince of experimenters on equal grounds.‘