The cut illustrates an arrangement of bulkhead doors for steamers. For the safety of ships provided with watertight collision bulkheads, it is imperatively necessary that dependence should not be placed on firemen and stokers for closing the doors. It seems clear that had the bulkhead door of the Oregon been closed before the collision occurred, that ship would still have been afloat. By the construction shown the doors cannot be left open, even when the coal. passers are at work. The door in the bulkhead, instead of entering into the coal bunker, has a chamber or well (built watertight) in front of the door of the bulkhead. This well has a second door fitted in it the same as the other one, both doors to slide easilYlup and down. and a locking bolt is carried on guides on a level with the top of these doors when they are shut down. This bolt extends exactly from the back of the one door over the top of the other door, and it always bears against the back of the door that is up, and extends over the top of the door which is down. It is thusclear thatso long as one door is open the other must remain shut until the other door is also down, to permit the locking bolt to slide from off the top of the one door over that of the other. The coal trimmers bring the coals into the compartment or well, they close the open door, slide the bolt over it, and then open the other. All may be done in a few seconds, even by manual effort, and in less if aided by steam or water. No space is lost, as This interesting invention is due to Mr. Laurence Heill, C.E., of Glasgow, Scotland. He refuses to patent his invention, preferring to dedicate it to the service of the public. It really seems as if it would operate as an insurance against sinking and be a factor in the rating of a ship comparable to the bulkhead itself. The Latest Summary of Pasteur's Work. Up to April 14, Pasteur has inoculated 688 persons, presumably bitten by mad dogs, with only one death. He had also inoculated 19 Russians bitten by a mad wolf. Of.'these 19, 3 have died from hydrophobia—about 16 per cent. The usual per cent of deaths from the bites of mad wolves is said to be about 67. Since April 14, Pasteur has treated other Russians bitten by mad wolves and mad dogs. One of the former recently died from the effects of his wounds ; one of the latter from hydrophobia, after having been submitted to treatment. This makes in all 720 cases treated, with a total of 5 deaths from rabies, despite treatment. Pasteur has found that the rabies, resulting from wolf bites is the same as that of dogs,'and only more dangerous because the bites ofare more numerous and severe. Unprofitable Customers. Almost every machine-shop owner has suffered more or less from the friend who drops in to have a rivet put in his knife, the spring of his pistol fixed, or some other one of the million little odd tinkering jobs done. Of course, he does not expect to pay for it, “it is such a trifle, you know,” nor does the proprietor like to make a charge, and thereby lay himself open to being thought “ small.” When a charge is made, it is seldom commensurate with the cost of doing the work, and rarely, if ever, pays for the annoyance and diversion from more important work. Such jobs, it is safe to say, are always distasteful, but the proprietor does not know exactly how to refuse to do them. Not only do they take more time than would be supposed, but considerable time is wasted in getting back to regular work, and in many cases other employes have to wait on the one doing the job, machinery is idle, and the minds of the men have to go back and gather up the threads of the work in hand. Such jobs are an imposition, not intentional perhaps, because those imposing them are ignorant of the annoyance they cause, but this does not lessen their cost in any measure. The machinist who does not want such work should plant himself squarely against it, and refuse to take it at all. A few words of explanation would satisfy any reasonable applicant.—Industrial World. Reward Offered for a New Invention. The mining owners of Ostraw Rarwin (Austria) have decided to offer a prize ' of 1,000 ducats for the best invention ' for preventing accidents in firing and blasting in dusty or gaseous coal mines, or rendering the operation harmless. The invention should fulfill the following conditions, namely: 1. Its use, effects, or explosion should not cause the coal dust to ignite. 2. It should not produce, after the explosion or use, more injurious gas than through the methods heretofore employed. 3. No specially difficult, dangerous, - long RAUB'S CENTRAL POWER LOCOMOTIVE. the well is filled with the coal first used. Steps are fitted inside the well to the deck to provide means of exit. Dearly bought experience proves that no reliance whatever can be placed on firemen or trimmers to shut the doors, as they regard it as unnecessary tyranny to be told to shut them when they are so soon to be opened again, and they consequently shirk it on all occasions. Testing Watertight Compartments. Warned by the fate of the Oregon, the Russian Government, says Engineering, has been inaugurating an exhaustive test of watertight compartments; which it contemplates applying to all new vessels, and probably to older ones as well. The man-of-war selected was the corvette cruiser Vitiaz, which was finished last autumn, and is under sailing orders for the Pacific this month. Five weeks ago an intimation was conveyed to the dockyard authorities at Cronstadt that the watertight compartments would be tested in succession, and instructions were given to survey them afresh, and make good any defects that might be discovered. If the official report is to be believed, every effort was made to meet the wishes of the Admiralty, yet when the compartments were actually ftllod with water the fluid gushed through numerous apertures which had escaped the eye, and in some cases to an extent which would have been troublesome at sea after a serious accident. To secure perfection several of the compartments were 'filled two or three times, and it was only after a deal of door adjusting and leak stopping that the corvette was pronounced fit to proceed to sea. A final test was then applied in the presence of the higher Admiralty authorities, a number of the nine large watertight compartments being filled at once without any leakage. Besides insuring the rectification of all defects in the watertight compartments, it is claimed in the report that the tests have proved of great service in training the crew; they have promoted confidence in the buoyancy of the vessel, and have led to several improvements of an important character. It has been Bug- gested that in this'year's naval maneuvers in the Baltic the tests should.be continued by ordering so many of the watertight compartments to be filled, in the event of a torpedo cutter approaching within hitting distance of a man-of-war; but the defects revealing themselves in the case of the Vitiaz have made the authorities apprehensive of ill results, unless -harbor tests are applied beforehand.