purchased large coal areas, undeveloped for the most part, in Glamorganshire. To save the inland transport he finally procured the establishment, in 1888-91, of furnaces and mills in connection with Dowlais, on the seaboard at Cardiff. He was induced by Lord Wimborne to continue his administration of the Dowlais undertakings down to the end of March 1897, though his trusteeship had expired more than twenty years previously. Under his regime Dowlais became in effect a great training school which supplied to similar undertakings elsewhere a much larger number of managers and leading men than any other iron or steel works in the country.
On the formation of the British Iron Trade Association in 1876, Clark was elected its first president, and his 'Inaugural Address' (Newcastle-upon-Tyne) attracted much attention, provoking considerable controversy in the United States by reason of its trenchant exposure of protection. Few employers of labour have ever studied the social well-being of their workers so earnestly as Clark. At his own expense he provided a hospital for the Dowlais workmen, while the Dowlais schools, the largest in the kingdom, owed their success almost entirely to his direction. He was an early supporter of the volunteer movement, and himself raised a battalion in the Dowlais district. He was chairman of every local authority in the place, and his manifold services in the work of local government are commemorated by a marble bust, the work of Joseph Edwards, placed in the board-room of the Merthyr poor-law guardians. He was sheriff of Glamorganshire in 1868.
Clark's reputation, however, mainly rests on his archaeological work, and, to a lesser extent, on his historical research, though these were but the relaxations of an otherwise busy life. For quite half a century he was recognised as the highest authority on all mediæval fortifications, and was the first to give a clear insight into the military and historical importance of the earthworks of this country, and especially to show the use made of the mound—'the hill of the burh'—in Norman times (Hartshorne). Before going to India he took a prominent part in the movement which brought about the foundation in 1843 of the Archæological Association (now the Royal Archæological Institute), and, after his return, was constantly associated with its work for the rest of his life contributing papers to its journal, attending its annual meetings, and acquiring a unique reputation as a field-lecturer, inasmuch as the castles visited were 'called up to their first life by his massive vigour' (Freeman, English Towns and Districts, p. 5). He was also one of three trustees of the Cambrian Archæological Association. Commencing with an account of Caerphilly Castle as early as 1834, he contributed to the 'Transactions' of various societies, and to the 'Builder,' a large number of articles dealing with his favourite subject. (For his communications to the Archæologia Cambrensis, beginning in 1850, see the ' Index ' to the first four series, 1892.) In 1884 these were collected in his 'Mediæval Military Architecture in England ' (London, 2 vols. 8vo) a work which is not likely to be superseded, though its information may be supplemented with minor additions of detail.
Next to his purely archaeological attainments should probably be ranked his knowledge of heraldry and genealogy. He wrote the article on heraldry for the 'Encyclopædia Britannica,' while his privately printed pedigree of the Babington family has been described as 'perhaps unsurpassed for its dimensions and grandeur of type.'
His other works were for the most part elaborate contributions towards the history of his adopted county of Glamorgan, the following being the more important among them: 1. 'Thirteen Views of the Castle of St. Donat's, with a Notice of the Stradling Family,' Shrewsbury, 1871. 2. 'Some Account of Robert Mansel and pf Admiral Sir Thomas Button,' Dowlais, 1883. 3. 'The Land of Morgan, being a Contribution towards the History of the Lordship of Glamorgan,' London, 1883, 8vo. 4. 'Limbus Patrum Morganiae et Glamorganiæ. Being the Genealogies of the Older Families of the Lordships of Morgan and Glamorgan,' London, 1886, 8vo. Most of these pedigrees had been published 'nearly a quarter of a century' previously in the 'Merthyr Guardian.' 5. 'Cartæ et Alia Munimenta quæ ad Dominium de Glamorgan pertinent.' Sumptuously printed, for private circulation only, this great collection of Glamorgan charters extends to 2,300 quarto pages, making four volumes, of which the first was issued in 1885 from a private press at Dowlais, and the other three (in 1890-1-3) from Cardiff. Clark also edited some devotional works by his father and his ancestor, Samuel Clarke (1599-1682) [q. v.], and wrote numerous articles on the history and antiquities of Glamorgan.
Clark died on 31 Jan. 1898 at Tal-y-garn, near Llantrisant, where he had resided during his later years, and was buried there at St. Ann's Church, which he had built to the