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290 chambers which are mounted upon a central shaft supported upon bearings throughout the whole length except that portion passing through the chambers. The general appearance of these pres- sure-chambers is shown in Fig. 5. The whole pump is in perfect hydraulic bal- ance. This feed pump on test, deliv- ered 18,000 gallons per hour against a boiler pressure of 220 lbs. per sq. in., and took 50 B. H. P.. to: drive. same, THE MARINE REVIEW giving self regulation and high and permanent efficiency at constant speed coupled with the modern speed prime movers in shape of electric motors, steam turbines, gasoline engines, etc., - finally removes the limitations of the centrifugal pumps entirely and_ the above illustration shows that there are few conditions of pumping that the Roturbo type of pump is not fitted for. * The Roturbo pumps are operated for SECTION OF IMPELLER ReES ROoTURBO PUMP showing a pump efficiency of 76.5: per cent. Fig. 6 shows the characteristic curve and efficiency for the above. An interesting example of a compara- tively low speed Roturbo pump running at 925 revolutions per minute gave the high effjciency of 84 per cent. The duty of this pump is 150 ft. lift and a delivery of 158,400 gallons per hour at the above speed, the diameter of the discharge pipe being 12 in. The curve shown in Fig. 7 gives the performance of the pump under test to meet stringent contract conditions. The overall efficiency of the pump and mo- tor was shown to be 75 per cent. When this pump was tested at the works the following results were pro- cured: Starting from the duty point, viz., 158,400 gallons at 150 ft, head, the power is reduced from 120 H. P., to less than 40 H. P., as the discharge valve is closed. To the right of the curve when the discharge valve is opened so as to reduce the head against which the pump is working, the volume with minimum pressure is increased to double of that at 'the duty, showing that there is no throttling in the pump and no reduction of capacity. The characteristic of the pump is shown in the power curve which, in- stead of rising at the lower heads, is actually reduced from 135 H. P. to 105 H. P., due to the turbine effect of the impeller, Therefore, the Roturbo type of pump pumping sewage, mines, coal mines, boiler feeds, pressure augmentors for city service, fire protection, dock pump- ing, cooling towers and _ condensing plants, etc. They are also being used with ex- ceptional advantage for fire-engine ser- vice. Fig. 8 shows an application of the -Rees Roturbo pump for this ser- vice driven by a gasoline engine. This machine is equipped with a 50- H. P. engine adapted to drive either the machine or the pump as _ required. The outfit attains a speed of 40 miles per hour when running on good roads. The efficiency obtained at the pump, Viz Be Poo to, W. HH. PR. was 74 per cent when working at the duty and against a pressure of 120 lbs. per sq. in. Due to the self-regulating characteris- tics of this pump the streams can be' delivered through any number of hose- pipes without overloading the engine when the head is reduced. Conse- quently, the maximum power of the engine can be utilized at all times, no matter what the head may be, since it runs at constant speed. Operating Ships Without License The steamboat inspection service has issued the following circular to Owners, agents and licensed officers of vessels which is self explanatory. The circular is unequivocal in tone and apparently the service has be- come exasperated over the frequent September, 1912 repetition of a condition for which there rarely or never is any real- excuse: Section 4438, Revised Statutes, pro- vides that-- : It shall be unlawful to employ any person or for any person to serve as master, chief mate, engineer or pilot of any steamer or as master of any sail vessel of over 700 gross tons or of any other vessel of over 100 gross tons carrying passengers for hire who is not licensed by the in- spectors; and anyone violating this section shall be liable to a penalty of $100for.-each offense. Violations of this character are becoming more frequent; and, in the appeals to the department for the mitigation or remission of penalties which have been imposed, the li- censed officers offer as an excuse or explanation that they did not know that their licenses had expired, or that they had forgotten to have the license renewed, or that they were mistaken as to the date of expiration, ete. Owners offer the excuse that they have no knowledge of the life of the license, or that as long as they are assured that the officer has a _ valid license when they engage him their responsibility ends, or that they can not be expected to know when a li- cense expires, etc. There is no reason why an officer should not renew his license upon its expiration and why owners should not be kept informed of the status of their officers, as every license is- sued states on its face the character of the 'license and that it is issued for a "term of five years' from a - date given. on the license, and the department takes this occasion to notify all persons interested that hereafter no leniency may be expect- ed and no mitigation or remission of penalties respecting violations of section 4438, Revised Statutes, will be considered, except that it can be sat- isfactorily explained that such viola- tions are not the result of indiffer- ence or neglect on the part of either owners or officers. BEN]. Si CABLE, Acting Secretary. thes United States Port- land, Ore., is advertising for sealed pro- posals for the construction of two steel hull 24-in. dredges, Multnomah and Wahkiakum, which will be received at his office, 321 Custom house, until 11:00 a. mh; Sept. 30, 1912, Information may be obtained by application to J. F. Mc- Indoe, major of engineers. engineer,