7o6 POPULAR SCIENCJ^ MONTHLY. 



for her large crew, but equipped Avith au armameut 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 thick- 

 ness 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 hun- 

 dred 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, tur- 

 bine engines would appear to present some considerable advantages. 

 In the first place they would effect a reduction in weight of ma- 

 chinery 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 SUEVIVAL OF MEDIEVAL CREDULITY. 



By Pkofessou E. P. EVANS. 

 [Concltided .'\ 



IN the seventeenth year of her age Miss Diana Yaughan joined 

 the Freemasons, entering the lodge (" triangle ") of " The 

 Eleven Seven," at Louisville, and passing rapidly through the differ- 

 ent 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 sacra- 

 mental character of the Eucharist. She mnintninod that tliere 



