Pascal solved the hitherto refractory problem of the general quadrature of the cycloid, and proposed and solved a variety of others relating to the centre of gravity of the curve and its segments, and to the volume and centre of gravity of solids of revolution generated in various ways by means of it.
Fire-clays include all those varieties of clay which are very refractory to heat.
As some of these substances (for example, lead sulphide and copper pyrites) are readily fusible when first heated, but become more refractory as part of the sulphur is dissipated and oxygen takes its place, it is important that the heat should be very carefully regulated at first, otherwise the mass may become clotted or fritted together, and the oxidizing effect of the air soon ceases unless the fritted masses be broken small again.
The materials used in the construction of furnaces are divisible into two classes, namely, ordinary and refractory or fire-resisting.
They give wares of remarkably fine texture and surface, combined with high refractory character.
Alumina as a refractory material is chiefly used in the form of bauxite, but its applications are somewhat special.
By the continuous injections under the skin, in increasing doses, of the toxins of certain pathogenic micro-organisms, such as that of diphtheria, an animal-usually the horse-may be rendered completely refractory to the disease.
On the 9th of February 1792, he succeeded in having a law passed sequestrating the possessions of the émigrés, and demanded, though in vain, the deportation of refractory priests to French Guiana.
Hermann as president and Fouquier-Tinville as public prosecutor, the tribunal terrorized the royalists, the refractory priests and all the actors in the counter-revolution.
Made of exceedingly refractory clay, it under went stoving for more than three weeks, and was consequent!) remarkable for its hardness and metallic timbre.
In this process all the anode metals pass into solution except iridium and other refractory metals of that group, which remain as metals, and silver, which is converted into insoluble chloride; lead and bismuth form chloride and oxychloride respectively, and these dissolve until the bath is saturated with them, and then precipitate with the silver in the tank.
He had defeated all enterprises by rivals against his throne; he had broken down the power of local chiefs, and tamed the refractory tribes; so that his orders were irresistible throughout the whole dominion.
The Convention took measures against the emigres and the refractory priests.
A difficulty with Venezuela, resulting in British and German co-operation to coerce that refractory republic, caused an explosion of antiGerman feeling in England and some restlessness in the United States, but the government brought the crisis to an end by tactful handling and by an ultimate recourse to arbitration.
One practical outcome of these researches is the method now always adopted of sterilizing by a succession of gentle warmings, sufficient to kill the developed micro-organisms, instead of by one fierce heating attempting to attack the more refractory undeveloped germs of the same.
Cytological details of nuclear behaviour among the lichens are, however, difficult to obtain owing 'to the slow growth of these forms and the often refractory t' nature of the material in the matter of preparation for microscopical ex amination.
Alumina itself is so refractory that it cannot be melted save by the oxyhydrogen blowpipe or the electric arc, and except in the molten state it is not susceptible of decomposition by any chemical reagent.
He had to contend, like his predecessors, with the perennial hostility of the burgher aristocracy of Amsterdam, and at times with other refractory town councils, but his power in the States during his life was almost autocratic. His task was rendered lighter by the influence and ability of Heinsius, the grand pensionary of Holland, a wise and prudent statesman, whose tact and modera tion in dealing with the details and difficulties of internal administration were conspicuous.
Moist undried, sand, but sometimes of iron covered with a refractory coating to protect it from being melted or overheated by the molten cast iron.
16) in which this wonderful process is carried out is a huge retort, lined with clay, dolomite or other refractory material, hung aloft and turned on trunnions, DD, through the right-hand one of which the blast is carried to the gooseneck E, which in turn delivers it to the tuyeres Q at the bottom.
S, Refractory lining.
Potassium bisulphate is useful in the preliminary treatment of refractory aluminous ores.
When he was ready he used his new troops, before turning them against their chief enemy, the Magyars, to punish refractory Slavonic tribes; and he brought under temporary subjection nearly all the Slays between the Elbe and the Oder.
The cylinders are made of steel plate, lined with refractory bricks, are carried on rollers at a slight angle with the horizontal, and are rotated by power.
The cyanide process, introduced about 1890, is now one of the most important factors in the utilization of low-grade and refractory gold and silver ores.
By treachery and compelled him to commit suicide; but the Armenian magnates proved refractory, placed Arsaces son Pap on the throne, and found secret support among the Romans.
But the large Province of Khora~an, of which Meshed was the capital, had never been other than a nominal dependency of the crown since the death of Nadir; and in the autumn of 1830 the shah, under Russian advice, assembled a large force to bring into subjection all turbulent and refractory chiefs on the east of his kingdom.
The league prescribed uniform laws, standards and coinage; it summoned contingents, imposed taxes and fined or coerced refractory members.
The Vatican accepted his proposal, but the Italian Chamber proved refractory, and, though dissolved by Ricasoli, returned more hostile than before.
A silver ore is either free-milling or refractory, that is, the silver mineral is readily amalgamated or it is not.
The yield in silver is low unless the ores are exceptionally free-milling; the bullion produced is high-grade, as refractory silver minerals are hardly attacked.
The Francke-Tina process, named from Francke, German consul at Bolivia, and tina, the wooden vat in which the process is carried out, was developed in Bolivia for the treatment of refractory ores rich in zinc blende and tetrahedrite (fahl-ore).
The Frisian peasants and fisher folk loved their independence, and were equally refractory to the rule of any distant overlord, whether count or bishop. Dirk VI.
To an exterior in these early years somewhat heavy and uncouth, he united a manner which, by universal testimony, was irresistibly winning, with a fund of genuine but simple humour and fun that would break out on the most unlikely occasions, and in after years enabled him to overcome difficulties and mellow refractory chiefs when all other methods f ailed.
An abbot also had the power of excommunicating refractory nuns, which he might use if desired by their abbess.
Perhaps it was his gift of oratory which suggested his appointment as bishop of the refractory men of Devon and Cornwall.
At the same time the application of the Civil Constitution of the Clergy roused the whole of western La Vende; and in face of the danger threatened by the refractory clergy and by the army of the migrs, the Girondins set about confounding the court with the Feuillants in the minds of the public, and compromising Louis XVI.
Owing to the decrees against the comte de Provence, the emigrants, and the Th refractory priests, voted by the Legislative Assembly dee~.
Whilst the insurrection in La Vende was spreading, and Dumouriez falling back upon Neerwinden, sentence of death was laid upon migrs and refractory priests; the treachery of Dumouriez, disappointed in his Belgian projects, gave grounds First corn- for all kinds of suspicion, as that of Mirabeau had mittee ot formerly done, and led the Gironde to propose the public new government which they had refused to Danton.
The attempt of the counter-revolutionaries to make an army for themselves out of the guard of the Legislative Assembly, and the success of the Catholics, who bad managed at the end of August 1797 to repeal the laws against refractory priests, determined the Directory to appeal from the rebellious parliament to the ready swords of Augereau and Bernadotte.
He also addressed a letter of remonstrance to Acacius; but the latter proved refractory, and sentence of deposition was passed against him.
Oxide of chromium and chrome iron ore have been proposed as refractory crucible materials.
It is very refractory, and is applied by mixing with water and some bond, such as sodium silicate or gas-tar.
Kilburn Scott, "Refractory Materials for Furnace Linings," Faraday Soc., 1906, p. 289).
The latter, especially when brought to the burning point at a high temperature, produces a heat that can be resisted by the most refractory substances only, such as silica, alumina and magnesia.
So completely had the state dominated the church that religious persecutions had become state persecutions, and Bonner was acting as an ecclesiastical sheriff in the most refractory district of the realm.
The country was flooded with Jesuits and friars, whose arguments were reinforced by quartering troops, veterans of the Indian wars in Mexico, on the refractory inhabitants.
Being thus soluble in salt water it cannot, of course, be salted out like common soaps; but if a very concentrated salt solution is used precipitation is effected, and a curd soap is separated so hard and refractory as to be practically useless.
The condemnation of the " heretics " by the Patriarch led to their repudiation by the community of Vatopedi, and at the instance of the Russian ambassador at Constantinople the refractory monasteries were subjected to a rigorous blockade.
The furnace used by Henri Moissan in his experiments on reactions at high temperatures, on the fusion and volatilization of refractory materials, and on the formation of carbides, suicides and borides of various metals, consisted, in its simplest form, of two superposed blocks of lime or of limestone with a central cavity cut in the lower block, and with a corresponding but much shallower inverted cavity in the upper block, which thus formed the lid of the furnace.
Moissan showed that at this temperature the most stable of mineral combinations are dissociated, and the most refractory elements are converted into vapour, only certain borides, silicides and metallic carbides having been found to resist the action of the heat.
Intelligence of these events reached Bolivar while in the north of Colombia, and he lost no time in preparing to march against the refractory troops, who formerly had placed such implicit confidence in him.
The city proved indeed a refractory member of the new league; and, after the death of William the Silent, the Utrechters, jealous of the influence of their old enemies the Hollanders, refused to recognize the authority of the council of state, and elected a stadtholder of their own.
Formerly bullion was melted in crucibles made of refractory clay, but they are liable to crack and require careful handling These were succeeded by iron crucibles, especially for melting silver, and these have now been generally replaced by graphite (plumbago) crucibles made of a mixture of clay and graphite.
The treaty of 1818 gave effect to this arrangement, Britain guaranteeing the prince against external enemies and refractory chiefs; he, on his part, pledging himself to be guided by her representative in the administration of his state.
On account of its refractory nature, it is employed in the manufacture of crucibles, furnace linings, &c. It is also used in making hydraulic cements.