above its junction with the Vaal. The streets are lined with fine willow trees, and there are public grounds in which are nurseries and a showyard. Golf links add to the attractions of the place, which is one of the healthiest in the Transvaal. In the neighbourhood are gold-mines; the reef appearing to be a continuation of the Witwatersrand reefs. The Vaal river goldfields, of which Venterskroon is the centre, are 16 to 20 m. south-east of Potchefstroom.
Potchefstroom was founded in November 1838 by Hendrik Potgieter, and is the oldest town in and first capital of the Transvaal. In 1862 it was the scene of civil war between rival Boer factions. In 1880–81 the garrison camped outside the town was besieged by Boers under Commandant P. A. Cronje. The British troops (250 in number) were confined to a fort 25 yds. square and lost over a third of their strength in killed and wounded before they surrendered on the 21st of March, the investment having begun on the 18th of December 1880. Charges of treachery were brought against Cronje for failing to notify the besieged that an armistice had been agreed to by the Boer leaders. Of this armistice Colonel R. W. C. Winsloe, who was in command of the British, became aware before the surrender took place. On the suggestion of Commandant General Joubert the capitulation was considered as cancelled and a detachment of British troops reoccupied the town until the conclusion of peace. In the Anglo-Boer War of 1899–1902 Potchefstroom was occupied by the British without opposition. (See Transvaal: History.)
Potemkin, Grigory Aleksandrovich, Prince (1739–1791), Russian statesman, was born at Chizheva near Smolensk. He was educated at the Moscow University, and in 1755 entered the “Reiter” of the Horse Guards. His participation in the coup d’état of the 8th of July 1762 attracted the attention of the new empress, Catherine II., who made him a Kammerjunker and gave him a small estate. The biographical anecdotes relating to him during the next few years are obscure and mostly apocryphal. In 1768 he quitted the Guards and was attached to the court as a Kammerherr, but in 1769 he volunteered for the Turkish War and distinguished himself at Khotin, Focshani and Larga, besides routing the Turks at Olta. It was not till 1771 that he became Catherine’s prime favourite. In that year he was made an adjutant-general, lieutenant-colonel of the Preobrazhensky Guards, a member of the council of state, and, in the words of a foreign contemporary diplomatist, “the most influential personage in Russia.” Somewhat later he was created a count, and appointed commander-in-chief and governor-general of “New Russia,” as the conquered provinces in the Ukraine were then called. In 1776, at Catherine's request, the emperor Joseph II. raised Potemkin to the rank of a prince of the Holy Roman Empire. In 1775 he was superseded in the empress’s graces by Zavadovsky; but the relations between Catherine and her former lover continued to be most friendly; and his influence with her was never seriously disturbed by any of her subsequent favourites. A whole mass of facts testify to the enormous and extraordinary influence of Potemkin during the next ten years. His correspondence with the empress was uninterrupted. The most important state documents passed through his hands. Catherine loaded him with gifts. He was deeply interested in the question of the southern boundaries of Russia and consequently in the fate of the Turkish Empire. It was he who, in 1776, sketched the plan for the conquest of the Crimea which was subsequently realized; and about the same period he was busy with the so-called “Greek project,” which aimed at restoring the Byzantine Empire under one of Catherine’s grandsons. In many of the Balkan states he had well-informed agents. After he became field marshal, in 1784, he introduced many reforms into the army, and built a fleet in the Black Sea, which, though constructed of very bad materials, did excellent service in Catherine’s second Turkish War (1787–92). His colonizing system was exposed to very severe criticism, yet it is impossible not to admire the results of his stupendous activity. The arsenal of Kherson, begun in 1778, the harbour of Sevastopol and the new fleet of fifteen liners and twenty-five smaller vessels, were monuments of his genius. But there was exaggeration in all he attempted. He spared neither men, money, nor himself in attempting to carry out his gigantic scheme for the colonization of the south Russian steppes; but he never calculated the cost, and more than three-quarters of the design had to be abandoned when but half finished. Catherine’s famous expedition to the south in 1787 was a veritable triumph for Potemkin; for he contrived to conceal all the weak points of his administration and to present everything in a rose-coloured light. On this occasion he received the title of prince of Tauris. The same year the second Turkish War began, and the founder of New Russia took upon himself the responsibilities of commander in-chief. But the army was ill-equipped and unprepared; and Potemkin in an hysterical fit of depression gave everything up for lost, and would have resigned but for the steady encouragement of the empress. Only after Suvarov had valiantly defended Kinburn did he take heart again, and besiege and capture Ochakov and Bender. In 1790 he conducted the military operations on the Dniester and held his court at Jassy with more than Asiatic pomp. In 1791 he returned to St Petersburg where, along with his friend Bezborodko (q.v.), he made vain efforts to overthrow the new favourite, Zubov, and in four months spent 850,000 roubles in banquets and entertainments, a sum subsequently reimbursed to him from the treasury. Then the empress grew impatient and compelled him (1791) to return to Jassy to conduct the peace negotiations as chief Russian plenipotentiary. On the 5th of October, while on his way to Nikolayev, he died in the open steppe, 40 m. from Jassy, in consequence of eating a whole goose while in a high state of fever.
Very various are the estimates of Potemkin. Neither during his life nor after his death did any two people agree about him. The German pamphlet: Pansalim Fürst der Finsterniss und seine Geliebte, published in 1794, is a fair specimen of the opinion of those who regarded him as the evil genius of Catherine and of Russia. But there were many, including the empress herself, who looked upon him as a man of manifold and commanding genius. He was indubitably the most extraordinary of all the Catherinian favourites. He was an able administrator, but wanting in self-control. Licentiousness, extravagance and an utter disregard for human life were his weak points, but he was loyal, generous and magnanimous. Nearly all the anecdotes related of him by Helbig, in the biography contributed by him to the journal Minerva (1797–1800), and freely utilized by later biographers, are absolutely worthless.
See V. A. Bilbasov, Geschichte Katharinas II. (Berlin, 1891–1893); C. de Larivière, Catherine la Grande d'après sa correspondence (Paris, 1895); Anonymous, La Cour de Catherine II. Ses collaborateurs (St Petersburg, 1899); A. V. Lopukhin, Sketch of the Congress of Jassy, 1791 (Rus.; St Petersburg, 1893); The Papers of Prince Potemkin, 1744–1793 (Rus.; St Petersburg, 1893–1895).
(R. N. B.)
Potentilla (nat. order Rosaceae, q.v.), a border and rock garden plant. Many of the species bear brilliantly coloured flowers and graceful foliage. A soil of a good loamy staple, enriched with rotten dung, will grow the potentilla to perfection. Potentillas may be increased, though not very freely, by parting them into as many pieces as there are crowns, the side growths being those which can usually be thus separated. This may be done in autumn or spring, and the plants will generally bloom the following season. The species and some of the varieties reproduce true from seed, and are readily increased by that means. The following are some of the best kinds: aurea, atrosanguinea, davurica, formosa, nitida, n. atro-rubra, speciosa, tridentata, and villosa.
Potentiometer, an instrument for the measurement of electromotive force and also of difference of electric potential between two points. The term potentiometer is usually applied to an instrument for the measurement of steady or continuous potential difference between two points in terms of the potential difference of the terminals of a standard voltaic cell of some kind, such as a Clark or Weston cell. The modern potentiometer has been developed out of an arrangement due to J. C. Poggendorff, employed also by J. Latimer Clark. but converted