Evening Star Newspaper, February 23, 1930, Page 12

A—12 THE SUNDAY STAR, WASHINGTON, CAVITATION TESTS CONDUCTED HERE Naval Designers Watch Pro- peller Action on Models at Navy Yard. Have you heard of cavitation? | The word is one which is used almost | exclusively by designers of naval vessels | and their power plants, and while it | may not mean much to the layman, it | means a great deal to the naval de signer, who seeks the maximum in speed from his power plant and the propellers which push a vessel through the water. Just now cavitation is receiving a lot | of attention from the highly trained | technical men who design the craft | which uphold the power of Uncle Sam | on the high seas. 'If one of the new 10,000-ton cruisers which the Govern- | ment plans to build is a knot or two slower than cruisers of a similar class owned by an enemy power, it may mean the destruction of the United States ship. This disparity in speed is likely to be caused by cavitation. Briefly, cavitation is the condition ob- taining when a propeller is driven faster than can be accommodated by the water in its vicinity. Propellers of a vessel can be driven 50 fast that they create a vacuum behind the blades, which is not filled with water fast enough to furnish the thrust which comparatively imcompressible water would furnish if it remained at the blade of the propeller. So cavitation is a real phenomenon, and the solving of the problems con- nected with its manifestations have a very real valué in war and peace times. If cavitation tan be reduced or its ef- | fects neutralized. marine engineers will have partially solved the problem of | securing the utmost in marine speed | with the minimum power consumption. And reduction of cavitation some day may mean winning or losing a naval battle for the United States. Scientists Conduct Tests. In a long. low building at the Wash- ington Navy Yard keen-eved scientists | today are watching closely the results | of tests on models of destroyers and cruisers made exactly like the larger | vessels will be, but on a smaller scale and are discovering some facts tha may _be of considerable benefit in mal ing Uncle Sam’s sea fighters the fastest | things afloat. Delicate, intricate and | highly sensitive instruments record the facts on the small scale models as they are drawn and propelled through the | water in a great basin 470 feet long, made to reproduce as nearly as possi- ble the actual conditions of a ship in her own element. All over the United States shipbuilders and constructors watch the work at the model basin of | the Washington Navy Yard with the interest they must show to keep abreast of the latest developments in marine design. Cavitation is only one of the nany problems which still await solu- | tion, for even though marine construc- | tion has progressed considerably since the first caveman set forth on the un- known sea in a dugout canoce, many problems still remain to be solved. Plan 3 More Model Basins. ‘The experimental model basin is the only one of its kind in this section of the country, but it may have a com- petitor in the private shipbuilding field shortly, for a ship construction con- cern at Newport News, Va. is consid- ering bullding a model basin. The Navy Department now has plans for three more model basins to handle ex- | periments on the three chief phases of the work which will lead to advances in the scence of marine engineering and construction. These three phases are Ship model experimental A - plane and motor boat model work and expe: tal work in connection with shallow-draft craft, such as tugboats and river craft. The main use for the existence of model basins has been the wish to ob- tain the fastest vessels for the mini- mum expenditure of power. To deter- mine how marine design may be im- proved to obtain this end, the basin at the Washington Novy Yard was built in 1898. and has continued to expand and grow in importance until today it is recognized as the main laboratory 19§ improvement in marine engineering science. The building housing the basin is of | brick with a steel trussed roof and a | monitor skylight nearly its entire length. | Dimensions of the water surface are approximately 470 feet by 42 feet, the | depth is 14 feet and more than 1,000.000 | gallons of water are required to fill it. | The water is supplied by the city mains and is not treated in any way. Because of the lessened density of city water | as_compared with sea water, a com. pensating factor of 215 per cent of dif- | ference must be allowed in the compu- tations of the draftsmen and marine architects. In this besin models of every ship of importance built by the | United States Navy since 1898 have been tested for speed, conformation and other factors which govern that quality known as “seaworthiness.” Propelied by Electric Motors. | On a moving carriage propelled along | rails by great electric motors models of ships are drawn through the water at, speeds running up to 18 knots an hou: while their own small propellers cleave | the water at their miniature sterns. This carriage is a_huge affair, of more than 40 tons in weight and moving at such speed in such a limited space, its | control must be perfect. It must be | stopped from maximum speed within a limited erea, and for this purpose many safety devices have been incorpo- | rated to prevent the great mass of steel from leaving its rails and crashing through the end of the building. “Why would it not be possible to | equip light cruisers with steps or flanges | which would give them something of | the speed of hydroplanes and fast, light speed boats equipped with such devices?” one of the marine draftsmen was asked. “Because,” he said, “these craft do not get up enough speed to use the ma- rine steps and their construction would be more apt to be a drag than a “In this matter of cavitation, was asked, “why would 1t not be pos- aibie by a vane treatment of the bot- tom of the ship to cause a_depression | of the ship’s propellers at high speed and this reduce the vacuum by getting | the propellers far below the surface?” | “That_would raise the bow from the HOIG PIANDS FOR_ EN FREE TUNING UNDER RENTAL CONTRACT WORCHS !llp G EST.1879 | of this nature could be produced, show- D. C, FEBRUARY 23, 1930—PART _ONE. TESTING BEHAVIOR OF WARSHIPS BY TINY MODEL s The model ship basin at the Washington Navy Yard. surface,” he replied, “and would not aid in solving cavitatton appreciably, because the propellers still would re- volve at a speed high enough to form | a vacuum behind them.” In addition to testing of models the engineers have gone exhaustively in the model basin into propeller design, pitch of blade and location of screw on the ship stern and other factors that enter | into production of maximum speed with | minimum power. In the matter of pro- peller design they now are taking a leaf from the book of the designers of airplane wings and are experimenting with screws whose leading edges are comparatively thick, trailing out to a thin wedge at the rear Saves Time and Money. | To shgl’ how the basin helps in sav- ing time and money, the case of the | battleship Georgia may be cited. small model of the ship prepared from | the designs for the bigger vessel, was made in the extensive model shop, | which is a necessary adjunct of the basin. As a result of the tests in the | applications showed that every State |abroad, and only 15,636 went on busi- | would take. basin and changes in the model designs, | was represented by some travelers, but | ness. 8 saving of 2,000 horsepower was real- | ized for the designed speed of 19 knots. | In the first destroyers, designed without | ' HOUSEWIVES AilE CHIEF VISITORSrl TO EUROPE, STATISTICS REVEAL Declare Themselves to By the Associated Press. Just who goes abroad and why nnd‘ where they go has been determined, by the statistical experts of the State De. | partment. Largest Number of Americans Applying for Passports Have No Occupation. Tllinois with 7.12. New Jersey with 7.63, and Massachusetts with 634 were the only other States contributing more han 5 per cent of the total. Ohlo, LEGEE CALLSNOTE ERAF GETS PERMIT OF PROTEST LEVITY Georgia Organization Insists! on Rejection of Statement | by Senator Harris. ‘i By the Assoclated Press. MILLEDGEVILLE, Ga., February 22.— Chairman Alexander Legge, in a letter | received here today, denied that he was | displeased with his recent visit to | Georgia and also expressed appreciation | for the reception accorded him at the | convention of the Association of Georgia | Fairs. The letter was to Attorney C. B. | McCullar, president of the association. | Chairman Legge’s visit to the State | was marked by Senator Harris' criti- cism of the Farm Board, open disagree- | ment with some of its policies by Com- missioner of Agriculture Eugene Tall- madge, the halting of Mr. Legge for | speeding by the sheriff in Jonesboro | and a subsequent letter to Representa- | tive Larsen in which the Farm Board | head indicated displeasure at his treat- | ment. Mr. Legge, however, later ex- | vlained that this letter was written in | “tevity.” Letter to Mr. Legge. Following the series of incidents, Mr. | McCullar wrote to Mr. Legge to the | effect that the fair association did not | approve of Senator Harris' attitude nor {of the criticlsm voiced by Mr. Tall- madge at the Milledgeville meeting, but | | that if the Farm Board head had vio- | lated the speed laws the sheriff was | justified in stopping him. In reply, Mr. | Legge sald: “Thank you for your kind letter of February 18. * * * So far as Sena- | | tor Harris' speech was concerned, he | was certainly entitled to his opinion, | Empire State. Pennsylvania with 9.39, | but I did feel that it was qumtlonuble' | whether it was wise to try to talk of | |our program to a Georgia audience at | | the same time the activities of the Farm Board were heing discredited by Last year, at least. the largest group | California and Michigan netted about |the senior Senator for the State. had no occupation at all, and most of them were going to Europe for travel, | rest and recreation. first in the list by occupations. A | classes represented more than 13 and tries” 2 per cent respectively. to the next occupational class of trav- | elers was & drop of 4 per cent, and | of Americans applying for passports 4 per cent each. Going to Western Europe were 67.78 per cent of the total, and the depart- Housewives were | ment estimated that another 18.65 per | quently described by Mr. Young These | cent who asked to visit “all coun-|Atlanta and Mr. Legge’s companion on | By the Associated Press. visited Europe also. Latin From these | America received only 4.1 per cent of | doing nothing more than having a little | the total. Nearly half of the travelers were | Suggests Speed Trap. “The Jonesboro incident was Kubflt; (of | | the trip) in the Atlanta papers. I was | joke with the congressmen who were 8o | insistent that I go, in connection with | “laborer” was the third classification. | naturalized, only 110,084 being native | which I was advised how easy it was | The analysis of the nearly 200.000 | that only New Yorkers go abroad en | masse. Fully 29.88 per cent of th applications came from New York Cit; Americans. Family aflairs took 68,315 More than 4,750 artists and actors left the country, while only 630 writers and 414 reporters went abroad. Students, teachers and secretaries model basin tests, the performance of |and 6.97 per cent more came from the | totaled about 10,000 each. these greyhounds of naval warfare was | not satisfactory and contractors wished to make changes involving expenses amounting to between $35,000 and $40,000. A few experiments made at | | the basin showed better results could be obtained. The cost of the changes was $2,500. Many specific instances ing how Uncle Sam saves money by the work of these painstaking scientists working in this great basin of water on miniature models of the ships which will one day form our first line of de- fense. But the work of the basin is not ton of the act which authorized construction of the basin, private shipbuilding and operating con- cerns have been having model work done at cost for some years. A new pet of the Navy technicians is | a water chamber through which water! is forced through great pipes under | considerable pressure, permitting ob- servation of the exact opposite of the | tests in the model basin. Here the water is forced against the model to be tested, while in the basin the models are forced through the water. Alongside the model basin chamber is a wind pressure tunnel, where air- plane design and construction is tested under conditions similar to those en- countered in the air. Here practically | every type of plane design ever used | has been tested, from the speedy scout planes of the pursuit type to the great bombers. Even the giant Zeppelin type | dirigibles have been tested in this wind tunnel. Eyes Examined Free! By A. S. SHAH, Registered Eyesight Specialist Kryptok Invisible Bifocal Lenses Toric Kryptok Bifocal Lenses (one pair to see near and Sold usually for $7.50 to $15.00. Special price this week. .. An Unusual Offer This Week First and best quality. far). Best lenses made. Toric Lenses Far Exclu- sive Optics Discount is allowed on Remember the Address American Radiator Products HOT WATER HEATING SALE OF EARLY COINS ‘ TO BE HELD IN LONDON‘I Collection of Saxon and English| Money Contains Interesting Specimens. LONDON (N.AN.A).—An extensive recourse during his stay in various baronial castles to a method of provid- ing himself with money to pay the troops, the method consisting of issu- ing coins from temporary mints. These were entirely of silver and irregular in sentation of the castle where they were struck. (Copyright, 1930. by North American News- paper Alliance.) shape, and they usually bore a repre- | and farthings minted at Durham, New- | IMPORTANT INFORMATION In connection with the above offer a 30% SHAH OPTICAL CO. 812 F St. N.W. Let Our Graduate Engineers GIVE YOU DETAILS No Cash Down Payment—take as long as 3 years to pay! American Heating 907 New York Ave. collection of Saxon and English coins is to be sold in London early next month It includes “silver pennies” used in the | tenth century and silver half pence | castle, York, Bristol and Berwick dur-| ing the reign of Edward III. There is also the famous double penny of Henry III, which brought $1,250 at a sale in | 1920. This remarkable coin, struck at | Canterbury, probably about 1260, weighs 45.8 grains. The Oxford crown of 1644 is par- ticularly interesting. It bears an|N equestrian figure of Charles I, holding | a drawn sword, his long scarf flowing | behind him. Beneath is a view of the | city of Oxford, with its name, “Oxon.” | placed immediately under the horse, between two steeples. Coins minted during the reign of Charles I are of great interest to col- | lectors, because when the King had to flee from one place to another he had | 2% Positively Relieved 7.00 7 $s Saved Are $$ Earned Oculists’ Prescriptions % 7 Established 16 2077 % 7 7 % PLANT Completely Installed Includes 18-in. boiler, 6 radiators, 300 ft. radiation. Engineering } Company Nat. 8421 Ninety-nine per cent of the passenger | automobiles in the Gold Coast of Africa are equipped with balloon tires, and each car requires 12 tires a year. /A 7 777 % 7777 77 72222 Starting Tomorrow! Ending Sales o — i T T OVER a thousand pairs . . . that were $3.95, $4.95, $5.85, $6.50. Various Sizes broken in each but arranged on racks, according So you can select and try them on yourself. charged, delivered or exchanged . . . but styles a kind . . to size. WHAT "" fl““’ | | to get there and about how long it | Even at the speed (he‘l sheriff objected to, we were not able to | make the trip within the estimates | | these gentlemen made. Therefore, I| | thought it was not out of the way to suggest to them that perhaps they were guilty of leading me into a speed trap. “I certainly could have nothing but the kindest feeling in regard to the cordial reception given me in Milledge- ville, * ¢ | Regrets Jokes on Congress. | | | Ruth Bryan Owen, Tepresents | Florida in the House, regrets that “Con- | | gress is so often in the humorous col- umns of the newspapers.” She told | the League for Political Education she wished the public could see the long hours_representatives put in their of- fices looking after the affairs of their | ' constituents. t Vie: s e gt lean- nd leathers. All sales final. . BARGAINS! 7th & K Sts. Store Only | the two were together drinking at the | 10 USE LAKEHURST Giant Aircraft Expected to‘; Come Here for Study of Flight ! to South America. i T AT | By the Associated Press. | Another visit to America by the Graf Zeppelin is in prospect for the near future. i With the announcement here that permission had been granted for the glant German airship to make use again of the landing faciiities at Lake- hurst, N. J., it was learned that Dr. ! Hugo Eckener, commander of the Zep- pelin, is planning a study of the possi- bilities of the airship In traffic between Europe and North and South Americ. At the Navy Department a letter was made public late yesterday from Dr. FEckener to Acting Secretary Jahncke, in which he expressed the opinion that journeys between these three coni- | nents, now requiring nearly four weeks | by water, could be accomplished by air- ip-in & week or 10 day: | letter _was presented to M. | Jahncke by F. W. von Meister, the | American representative of the Luft- schiffbau Zeppelin. It said the fllzl\l‘ could not be undertaken without assur- | ance that the Lakehurst airport couid | be used for refueling purposes. A place | has been reserved on the Zeppelin for a { representative of the United States Navy to make observation: FATE OF HORST LAD | REMAINS A MYSTERY *“Confessed” Slayer's Story Refuted by Other Suspects, Leaving Au- thorities. Without Reliable Clues. WOOSTER, Ohio, February 22.—The | disappearance ot Melvin Horst, 4, to- day apparently was as great a mystery as when he failed to return to his Orr- ville home December 27, 1928. ‘The “‘confession” of Charles Hannah, | 61, that he killed the boy was further | torn down with the declaration of Earl Conald, the other man held for ques- tioning, that the slaying would have been impossible as described by Hannah. The latest statement of Conald, who has corroborated Hannah's story that | time Melvin is supposed to have dis- appeared, left authorities admittedly at a loss as what to do today. Only a few hours before Conald's new account, two Akron men were re- leased when Hannah failed to identify them as the pair to whom he said he delivered Melvin's body. Hannah, who three times has confessed killing Mel- | vin, twice has named different places | where he said the body was buried, but i now professes not to know what be- | came of it. He has said he killed the | boy with a wooden scantling while he and Conald were drinking in a garage. |CHINESE GIRL SUES Daughter of Millionaire Merchant in San Francisco Asks Division | By the Associated Press. suit involving members of two of China- | town Fats and Loo Yee Tow: Superior Court here Evelyn Tong, 19, daughter of Sing Fat, millionaire plainant, and Paul Lo as the defendant. her child, Pauline, born October 7, and is wealthy enough to contribute $100 a | month for the child’s also asks for half of his property, said to run into six figures. A restraining or- der tying up Lo's Jackson street prop- |erty worth more than $40,000 and also his interest in a manufacturing com | pany was issued by Superior Judge C. J. | Goodell. Lo. who is married, told_her he would take her to China after he disposed of his property here and provided for his wife and children in this country. said he had offered to buy her child if it was a boy, but that if it was a girl, she “could keep it.” 77 ) / 727, 2 %% 7 . none KEEFER BEGINS DUTY IN RED CROSS HERE Retired Army Officer Has Been Member of Medical Corps Since 1890. Brig. Gen. Frank Royer Keefer, U. S, A.. retired, newly elected chairman of the District Chapter of the American Red Cross, assumed his new duties in that capacity yesterday. He succeeds Maj. Gen. George Barnett, U. 8. M. O. | ~As a member of the Medical Corps of | the Army since 1890, and as a former assistant surgeon general, he had long experience with the Red Cross. Gen. Keefer will have an office in the new chapter headquarters in the World War Memorial Builing at 1730 E street. He has had assignments as professor of military hygiene at the United States Military Academy, 1910 to 1914, and as commander of various military hospi- tals. In 1918 he was chief of the medi- cal division in the provost marshal general's pffice in Washington. From 1920 to 1922 Gen. Keefer served as chief surgeon of the American forces in Germany and in the same capacity for the 2nd Corps Area, New York, until 11927 In that year he hecame assistant surgeon general until his retirement from the Army. Gen. Keefer is a member of many | medical organizations and was decorated with the office of Legion of Honor by France. BRIG. GEN. F. R. KEEFER. FOR SUPPORT OF CHILD of Paul Lo’s Property. 'PROTECTION OF RURAL BEAUTY ASKED IN BILL Motor Car” Blamed for Littering of Eng- lish Countryside. By the Associated Press. LONDON, February 22. pervasive motor car’ was blamed by Sir Hilton Young. Conservative, in the House of Commons yesterday for en- dangering the beauties of the English countryside. Unless Parliament inter- e said, the country would be with unsightly = bungalows, higgledly-piggledy” industrial build- ings and ugly advertisement signs, A bill aimed at preservation of the beauties of the rural areas was given second reading without division. | Arthur Greenwood, minister of health, urged that something be done to pro- tect the face of the country against “the jerry-builders, the advertisers and the purbiind.” uited States OIL BURNER “AS GOOD AS ITS NAME” ! Consult us now, about installing SAN FRANCISCO, February 22.—A | wealthiest families, the Sing was on file in day, with Miss “All-Pervasive 1s merchant, as the com- Lo, Miss Tong alleges, is the father of 1 o “The all- upport. She Miss Tong, in her deposition asserted She Special Price yours, It can be done at once, with- out incony enipnce to the household. lnducements Be Free from Ashes, Dust, Right NOW! Dirt and Care next season. GET OUR PRICE ON THIS WONDERFUL BURNER Budget Payments Accepted MAURICE J. 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