XX11 CONTENTS. 



392. The manner of calculation described, art. 480, page 393. The manner of 

 calculation exemplified, art. 481, pages 39S to 396. Calculation continued, arts. 482 

 and 483, pages 396 and 397. Concluding remarks, art. 483, pages 397 and 398. 

 Reflections suggested by the importance of the subject, art. 484, page 398. 



The principles of stability as referred to steam ships considered, art. 485, pages 

 398 and 399. Reference to Tredgold's work on the Steam Engine, art. 485, page 

 399. Tredgold's method of simplifying the investigation, art. 486, page 399. His 

 subdivision of the inquiry, ib. The steps of investigation not necessary to be 

 retraced, art. 487, page 399. The expression for stability when the ordinates are 

 parallel to the depth, equation (290), art. 488, page 399. Remarks deduced from 

 the form of the equation, art. 489, page 400. The expression for stability in the 

 ease of a triangular section, equation (291), art. 489, page 400. The practical rule 

 for reducing the equation, art. 490, page 400. Example for illustrating ditto, art. 

 491, pages 400 and 401. The expression for stability in the case when the trans- 

 verse section is in the form of a common parabola, equation (292), art. 492, page 

 401. Remarks on its fitness for the purpose of steam navigation, as contrasted with 

 the triangular section preceding, art. 492, page 401. Comparison of the results, 

 art. 493, pages 401 and 402. Method of identifying the rule in the two cases, art. 

 494, page 402. When the transverse section is in the form of a cubic parabola, the 

 stability is determined by equation (293), art. 495, page 402. Remarks on the 

 superior form in this case, art. 496, page 402. Practical rule for ditto, ib. 

 Example for illustration, art. 497, pages 402 and 403. The stability determined for 

 a parabolic section of the 5th order, equation (294), art. 498, page 403. Remarks 

 on ditto, ib. General remarks in reference to the limiting forms of steam ships, 

 art. 499, page 403. When the ordinates of the transverse section are parallel to the 

 breadth, the stability is expressed by equation (295), art. 500, page 404. When 

 the transverse section is in the form of a triangle, the stability is expressed by 

 equation (296), art. 501, page 404. When the transverse section is in the form 

 of the common parabola, the stability is expressed by equation (297), art. 502, 

 page 404. When the transverse section is in the form of a cubic parabola, the 

 stability is expressed by equation (298), art. 503, page 404. This form superior 

 for stability, ib. When the transverse section is formed by a parabola of the 5th 

 order, the stability is expressed by equation (299), art. 504, page 405. Concluding 

 and general remarks, i&. The stability the same at every section throughout the 

 length, under what conditions this will obtain, art. 505, page 405. 



CHAPTER XIV. 



OF THE CENTRE OF PRESSURE. 



The centre of pressure, subject introduced, definition and preliminary remarks, 

 art. 506, page 406. The centre of pressure determined for a plane surface, art. 507, 

 pages 406, 407, 408, and 409. Formulae of condition, equation (302), page 409. 

 The centre of pressure determined for a physical line, art. 508, pages 409 and 410. 

 Practical rule for ditto, art. 509, page 410. Example for illustration, art. 510, 

 pages 410 and 411. The same determined when the upper extremity of the line is 

 in contact with the surface of the fluid, art. 511, page 411. The same principle 

 applicable to a rectangle, art. 511, page 411. The centre of pressure determined 



