When the scientific soirees begin, it is a sign that the scientific season is half gone; and now the Easter holidays are over, and scientific investigators are working the harder to complete their self-imposed tasks before summer comes with alluring smile to entice them to the seaside or the mountains. General Sabine, the President of the Royal Society, has held two soirees, in which, as usual, science and art were exemplified in a very interesting way, and ingenious mechanical models were exhibited. Among them, was Bidder's coal-winning machine, of which we have recently made mention ; and Price Williams' switch, which entirely does away with the numerous " points " seen at railway j unctions, and keeps the main line of rails always unbroken, whereby a frequent occasion of danger is avoided; and Milroy's excavator, which digs equally well on land and under water, and is very useful in digging out the foundations of bridges, or in sinking cylinders. It may be described as a heavy metal ring suspended by chain and pulley, and carrying a number of hanging flaps. These flaps, when the ring is lowered into place, and agitated, act as spades ; and when a sufficient quantity of earth or sand is loosened, they can be so regulated by another chain, that they bring it up to the surface, where it is dropped into a truck and carried away. From these particulars, it will be understood that deep holes can be dug, even under water, without sending men down to do the work. Well deserving of notice is a much improved safety-lamp for use in mines, invented by Mr. Story Horn of Newcastle-on-Tyne. It has long been known that the Davy lamp does not insure safety under all circumstances ; it is liable to become choked, the light is dim, and in some conditions it may occasion an explosion. These defects are remedied in Horn's lamp ; the light is good; accumulation ? of soot cannot take place to render it dim; and whenever explosive gas finds its way in, the construction of the lamp is such that it becomes its own extinguisher, puts out the flame, and thereby prevents an explosion, There are other points in its favor; but these we may omit, as in the foregoing brief sketch the merits of this new lamp are sufficiently set forth, and because it has been tested in the severest manner, and proved trustworthy. F. N. Gisborne, who has for years past made himself conspicuous by liia signals for use on board ship, in mines, factories, or dwelling-houses, has now brought out a method which, for simplicity and efficiency, escels all his previous inventions. First, he used galvano-electricity, then pneumatic tubes', and compressible air-chambers, both costly and liable to derangement. Now, with a balance-weight and a chain, he accomplishes all he desires with his system of signals. A captain standing on the bridge of a steamer can, by touchin'g the indicator, send an order to the steersman or the engineer, and see at once whether they obey without changing his position. And that which can be done in a ship can be done in a house, workshop, or mine, aiid by a simple mechanical arrangement, which can hardly fail to be received with favor. It has been already adopted in the five leading navies of Europe i and the great Prussian Iron-clad K'nig WilMlm, now building on the Thames, is fitted with a set of Gfisborne's signals, finished in a style which may truly be described as royal, A magneto-exploder, constructed by Breguet of Paris, was shown, which will fire a fuse, and consequently a cannon, at any distance from two feet up to two hundred miles.—And Clerk Maxwell exhibited a " Wheel of Life," containing what he calls dynamical diagrams, and these, when the wheel is set agoing, produce many remarkable phenomena of curves and their intersections. Thus, in the hands of a philosopher a toy becomes a means of illustrating the laws of curvilinear motion. Teachers of geometry and natural philosophy would find it useful.—And N. J. Holmes, who is among the foremost of our telegraphists, exhibited his new magneto-alphabetical-telegraph, which is one of the cheapest, if not the cheapest and simplest yet constructed. It comprises two circles of buttons, and the operator has only to touch button after button, and spell out his message as rapidly as he pleases. With this and other instruments before them, government will have a sufficient variety to choose from when they assume control of the telegraphs. Silver and Co. exhibited specimens of their Norwegian Cooking Apparatus, adapted to different purposes and eircum, stances, and of different dimensions. One wag provided with a thermometer to show the slowness of the rate at which the heat is lost. In one of the small boxes, a pint of water locked up boiling hot at eight o'clock in the morning, was still warm at six in the evening, And in like manner, the apparatus can be used as a refrigerator, and for preserving ice a considerable time unmelted. Mr, Graham, Master of the Mint, by a singularly ingenious experiment, showed the prodigious amount to which the metal palladium will absorb hydrogen : an amount exceeding by some hundreds of times its own bulk. Two ribbons of palla, dium, attached to the two poles of a battery, were seen loosely coiled in a water-bath. The current was turned on : the ribbons took in so much hydrogen that they expanded, uncoiled, and stretched themselves across the bath, as if alive. The current was reversed, the h)'drogen was thrown off, and the ribbons resumed their coil, They might have been compared to a couple of writhing worms. The eight wag amusing ; but it exemplified the researches by which Mr. Graham has thrown light on an important question in cosinical science, and led him to the discovery of the new metal, to which he has given the name of hydrogenium. From all this, it may be seen that a scientific conversazione represents a wide range of the progress of science ; while, as we proceed to show, it at the same time, exemplifies the arts, There was a specimen of the first beet-root sugar manufactured commercially in this country ; and specimens of the juice as expressed from the roots, and after defecation, and of the waste pulp which finds a ready sale as cattle-food,—There were two or three simple forms of filter which might be carried in the pocket.—There was a model of the viaduct now building- across the Holborn Valley.—A piece of inscribed bullock's hide, showing three capital letters and a rude hieroglyph, brought from the south-east coast of Africa, and supposed to be a message from survivors of ship wrecked crews, now prisoners in the interior of Somali Land.—There were photographs of Mount Sinai and of the surrounding country, taken by the party now engaged in surveying that remarka, ble land, and very wild and striking prospects do they represent. By and by, a model in relief, made at the Ordnance Survey Office, Southampton, will be brought out, and then scholars will be able to study and follow the route of the Is, raelites.—Not less remarkable are a series of photographs of Abyssinia, taken during the march to Magdala by the EoyaJ Engineers. The country therein represented must purely be the most rugged and precipitous in the world. Hannibal's march across the Alps must have been a holiday trip in com: parison.—Of quite another aspect were the views in the An tarctic regions, which are now becoming important, because from some part of those regions will the two nest transits of Venus have to be observed, and astronomers and others are beginning to inquire as to the best place in those desolate latitudes to establish a temporary observatory, and the prepa* rations to be made for the voyage. It is impossible not to wish success to their endeavors, for the settlement of some of the most important questions in astronomical science depends on good observations of the transits. It is recorded of some of the early Venetian painters that they laid on their colors with palette knives of different widths, and never used the brush. White Warren has revived the process, and exhibits a' number of pictures in oil, all painted with the knife, and with marked effect. Land and water pieces, houses, ruins, Gothic towers, and flower-beds present a sufficient variety to test the capabilities of the art and the artist. At present, he appears to be most successful in clonds. landscapes, and gardens.—Chambers? Journal IT is reported that ono day, when Lord Brougham hail driven to the House in the vehicle of his own invention, which Robinson, the coachmaker had christened after him, he was met in the robing room by the Duke of Wellington, who, after a low bow, accosted him. " I have always hitherio lived tinder the impression that your lordship will go down to posr terity ass the great apostle of education, the emancipator of" the negfo, the restorer of abused charities, the reformer of the law ; but no—you will hereafter be known only as the inventor of a carriage." " And I, my lord duke, have always been under the delusion that your grace would be remembered as the hero of a hundred battles, the liberator of Europe, the conqueror of Napoleon ; but no—your grace will be known as the inventor of a pair of boots." " Confound the boots," said the Iron Duke, " I had forgotten them.'. You have the bef* of it.'"