The accompanying engravings show an injector possessing many admirablefeatures, and, as will be seen,the aim of the manufacturers to make a perfect injector of the simplest construction, so as to be readily understood, has been most successful. This injector may be placed in any position, requires no change for varying pressures of steam, and the arrangement of its parts is such that the .tubes can be conveniently taken out and cleaned when required. As it has no special valves to become defective by use, the necessity of often sending the injector to the maker for repair is avoided; all of the valves and fittings here required can be found where supplies for steam fitters are furnished. The overflow valve can be located at any point between the injector and check valve that may be most convenient. This style of injector is made either non-lifting or lifting, the latter form being shown in perspective and section in the cuts. The Unique injector is made by the Rue Manufacturing Company, of Filbert Street, Philadelphia, Pa., and although it has been on the market but about a year, its success has been most flattering. It is made of gun metal, neatly finished, and all the parts are fitted to standard gauges. The Olive Oil Industry at Leghorn. As soon as the oil is received at the warehouse, it is placed temporarily in tanks and large earthenware jars to settle. New oil from the country is always thick, and in winter time generally congealed; after having been allowed to remain undisturbed for six or eight days it is. if still congealed, slightly heated before being placed in the filters, in a large tin lined pan, with a..ilouble bottom or jacket, through which steam is made to circulate. Thus the oil does not come into contact with fire, but is gently warmed by steam until it is quite fluid. The oil filter is a rectangular wooden tank, lined inside with tin, and it is divided into two compartments, an upper and a lower one. The oil is pumped into the upper compartment, and is allowed to filter through perfectly clean carded cotton—brought here from Malta, and preferred to any other on account of its purity—into the second or lower compartment, when it has again to pass through another layer of cotton, and finally comes out into a tank placed beneath the filter, from which, if perfectly bright, it is pumped into large marble lined tanks, holding about 50 tons of oil each. If the oil is not perfectly bright it is passed through the filters again and again until it becomes so. As a rule, however,. oil, particularly if of the finest quality, becomes perfectly bright after one filtering. In the large tanks the oil is allowed to remain undisturbed until required for exportation, whether for Great Britain or the United States of America. Concentratio n. Among the powers of the human mind that seem of themselves to make life worth living, that of concentration occupies a prominent place. To be able to fix the thoughts 01 the attention exclusively upon one subject, and to keep them there without wavering as long as is necessary, is a most important element of success in every occupation. It is a common mistake to think that although this ability is essential in professions, in literary pursuits, in the management of large enterprises, or in any position involving the laying of plans or the carrying out of systems, for the ordinary and commonplace worker, especially if his work be chiefly manual, it is of little consequence. ThiS is one of those fallacies which lie at the root. of much of the poor, inefficient, and inferior quality of work which is offered to the world in quantities far exceeding the demand. It is a well known fact that while hundreds of unserviceable men and women stand idle, waiting for employment which does not come, every one who is able and ready to do superior work in any department is eagerly caught up, and may almost command his own terms.. One of the most radical differences between these two classes of workers is this very power of concentrating the energy and strength of both body and mind upon the work immediately at hand. Two men, working side by side in the field or the factory, may be equally competent, as far as knowledge or physical strength or previous training go, to perform the labor before them. They begin with equal promise of good success, but in a short time, while one is persisting, the other is relaxing in effort. One pursues his work with unremitting zeal; the other spasmodically, with intervals of wandering thoughts and flagging attention. It is already an assured fact that the one who has acquired the habit of concentration will be the successful competitor. He will be anxiously sought for and re-engaged, while, the other will soon go to swell the Banks of, -the unemployed. It matters not what is to be done; from the simplest mechanical work. to the most abstruse and complex mental operation, the power of putting all the thought, energy, and attention on that and nothing else for the time being, will very largely determine the quality and amount of labor performed. To some extent this is a natural gift. We see children at play who, without other motive than their instinctive tendencies, persist continuously in any effort they make, or purpose they form, with a perseverance and earnestness which may well shame many of their elders, while others will be distracted by every passing object, and forget their determinations as soon as they are formed. Yet here, perhaps more than in most tendencies, culture and practice come in to-strengthen what is lacking. The discipline of the schools is most valuable in developing the concentrative power in the province of thought, and it would be a blessing to every child if, in some way, a like discipline helped him in the work of his hands. Like every other faculty, this, too, is strengthened by exercise. Each time we recall our scattering energies and wandering thoughts, and force them resolutely in one direction, we increase the power and develop the habit, and the exertion, at first painful and laborious, becomes in time easy and agreeable. Mr. Thomas A. Edison attributes his success as an inventor largely to this faculty, which he gained by steadfast exertion, once being able only to think upon a given subject for ten minutes before something else would come into his mind, but gaining by long practice the power of continuous and uninterrupted thought for hours on a simple topic. At one time he worked with his assistants in trying to connect a piece of carbon to a wire. Each time it would break, and they would spend several hours in making another, until after working in this way one day and two nights they finally succeeded. This habit does not necessarily make a person 80 absorbed in one thing as to become narrow and one-sided. He may become so by yielding wholly to a native impulse of dwelling on one thing; but the same self-control that concentrates his energies at will can also divert them at will into another channel when the proper time arrives. Many things rightly claim our attention, but none of them will receive it aright if our thoughts aimlessly wander from one to another, without compass or guide—Phila. Ledger. PROTECTIVE inoculation against yellow lever. is being tried extensively in the Mexican army,