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Page:Popular Science Monthly Volume 56.djvu/722

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POPULAR SCIENCE MONTHLY.

for her large crew, but equipped with an armament of light guns and torpedoes. Let us assume that her dimensions are about double those of the thirty-knot destroyers, with plates of double the thickness and specially strengthened to correspond with the increased size—length, four hundred and twenty feet; beam, forty-two feet; maximum draught, fourteen feet; displacement, twenty-eight hundred tons; indicated horse power, eighty thousand; there would be two tiers of water-tube boilers; these, with the engine space, coal bunkers, etc., would occupy the whole of the lower portion of the vessel; the crew's quarters and guns would be on the upper decks. There would be eight propellers of nine feet in diameter revolving at about four hundred revolutions per minute, and her speed would be about forty-four knots.

She could carry coal at this speed for about eight hours, but she would be able to steam at from ten to fourteen knots with a small section of the boilers more economically than other vessels of ordinary type and power, and, when required, all the boilers could be used, and full power exerted in about half an hour.

In the case of an Atlantic liner or a cruiser of large size, turbine engines would appear to present some considerable advantages. In the first place they would effect a reduction in weight of machinery and some increase in economy of fuel per horse power developed, both thus tending either to a saving in coal on the one hand, or, if preferred, some increase in speed.

The advantages are, however, less pronounced in this class of vessel on account of the smaller relative power of the machinery and the large quantity of coal necessary for long voyages, but the complete absence of vibration at all speeds, not to mention many minor considerations of saving in cost and reduced engine-room staff, are questions of considerable importance.

 

A SURVIVAL OF MEDIEVAL CREDULITY.
By Professor E. P. EVANS.

[Concluded.]

IN the seventeenth year of her age Miss Diana Vaughan joined the Freemasons, entering the lodge ("triangle") of "The Eleven Seven," at Louisville, and passing rapidly through the different grades until the "Elect Palladistic Knighthood" was conferred upon her after she had given satisfactory proofs of her Luciferian orthodoxy. One thing she refused to do—namely, to stab the host with a dagger—since this act implied a recognition of the sacramental character of the Eucharist. She maintained that there