122 Transactions of the Royal Canadian Institute 



which also had full sail power. Naval architects of the English Admir- 

 alty were not enthusiastic over the type, and two of the you'nger ones 

 made calculations which indicated to them that the Captain was not safe. 

 But early reports concerning the vessel and experience with her indicated 

 that she would be a great success, so little attention was paid to the theor- 

 ists and their application of science until on September 7, 1880, in the 

 Bay of Biscay, with a moderate gale blowing, the Captain capsized with 

 a loss of 481 lives, including Captain Coles himself. The vessel was 

 perfectly safe until conditions were such t^at she heeled ov,er enough to 

 bring her deck edge well under water. After that, her righting force 

 rapidly fell off, and at a comparatively small heel became negative, 

 resulting in capsizing. Under the weather conditions existing, the force 

 of the wind against the sails of the Captain was sufficient to heel her 

 beyond her safety angle, and over she went. 



The prompt and thorough investigation into this disaster emphasized 

 the fact that the metacentric height is not the only factor which must 

 be considered in connection with stability. For safety, the range of 

 stability or the range over which the heeled vessel retains a tendency to 

 right is important. A vessel with a very small metacentric height may 

 be perfectly safe if it still retains a righting tendency at a large angle 

 of inclination. Large range of stability, or tendency to right at large 

 angles of inclination^, is a feature associated primarily with high free- 

 board. On the other hand, low-freeboard vessels have a comparatively 

 short range of stability, but they also may be perfectly safe if their 

 metacentric height and initial stability are very great so that a large 

 amount of work has to be done to incline the vessel throujgh its compara- 

 tively short range of stability. 



The moriitor type with very \dw freeboard and very short range of 

 stability but great metacentric height, giving perfect safety, has been 

 compared to a chip, which always sets itself parallel to the surface of the 

 water. A chip is obviously not in danger of capsizing in a seaway. At 

 the other extreme from the m.onitor we have the deep draught high free- 

 board vessel with little or no initial stability but a great range. Here 

 the extreme case may be regarded as that of a pole weighted so as to 

 float upright which, will return to the upright in time no matter how 

 much the sea may deflect it temporarily. 



This whole question is now fairly well understood, and the naval 

 architect — provided his calculations are correct — is enabled to adjust 

 his metacentric height as he will by varying the proportions and 

 dimensions of the ship to suit the position of the center of gravity and 

 type of vessel, the uncertain factor in connection with the preparation 

 of a design being the location of the center of gravity, which is the center 



