The stud was originally intended for the purpose of breeding pit-ponies for its owner’s collieries in Northumberland; and this purpose is reflected in the type which is characteristic of the “Londonderry” pony. It is commonly said that the governing formula of the stud was “as much weight as possible, and as near the ground as it can be got”; and, so far as it goes, this formula—admirably adapted as it is for defining a pit-pony—is no bad description of the result attained in many instances. While the original object of the stud was never lost sight of in its policy and management, it was carried out by skilful and enthusiastic breeders, who set themselves to eliminate defects of conformation which were common among the Island ponies. The consequence was a degree of breed improvement which is perhaps without a parallel as the result of less than thirty years of breeding and management. But not only is the source of improvement in the modern pony to be found chiefly in this one stud. It is also traceable—as in so many other breeds—mainly to a single animal. If it be true that the modern pony is substantially the “Londonderry” pony, it is hardly less true that the “Londonderry” pony is the pony that is bred from the horse Jack (16), foaled in 1871, which came into Lord Londonderry’s possession as a colt, and was the sire or grandsire of almost all the stallions used in the stud, as well as of a third of all the mares that are recorded as belonging to it. Some idea of the extraordinary predominance of Jack in the stud may be gathered from the entries in the first nine volumes of the ‘Shetland Pony Stud-Book,’ in whose tenth volume the dispersal sale of the stud at Seaham Harbour is recorded. We find that in the period covered by these entries, nineteen stud horses were used to a greater or less extent. Of these, in addition to Jack himself, there were his three sons, Laird of Noss (20), Lord of the Isles (26), and Odin (32); and his eight grandsons, Thor (83), Sigurd (103), Emeer (131), Runolf (62), Najal (75), Lava (121), and Otkell; while Oman (33), his great-grandson on the dam’s side, was also considerably used. We find also that these ponies related to Jack were much more extensively bred from than the unrelated sires, so that of the four hundred and ninety foals entered as produce, two hundred and forty-eight are by Jack and his three sons, and a hundred and sixty by his eight grandsons; while thirty-six are by Oman, and only forty-six by sires wholly unrelated to Jack. [Illustration: JACK (16).] An analysis of the list of dams bred from in the stud accentuates the meaning of these figures; since out of a total of a hundred and twenty-five entered in the Stud-Book, seventy-six are by Jack and his three sons, while ten are by his grandsons.