applicable to all storms in the Indian Ocean, viz. IN THE RIGHT HAND, OR STARBOARD SEMI-CIRCLE, THE WIND HAULS AGAINST THE SUN; AND IN THE PORT, OR LEFT HAND SEMI-CIRCLE WITH IT; the most dangerous octant is in the port semi-circle, in advance of the centre, abutting on the axis line, and in the great majority of cases, characterized by a S.E. wind, so that before recurving, a S.E. hurricane wind is the most dangerous. 29. A vessel, north of the axis line, has not near so much to contend with, as one south of it: if she take the gale on the N.W. margin, with the wind at S.W., by standing northward she may rapidly extricate herself, especially if the gale be about recurving; almost under any circumstances, by such a manœuvre, the centre of the storm and vessel are rapidly parting company. 30. The rotation of the wind in a storm violently agitates the surface of the ocean, producing a swell or storm wave, this wave is propagated in the same direction as the wind, characterizing the margin to which the swell is a tangent. The undulations thus rolling from the margin, both in advance and regression of the storm itself, encounter each other and produce in the area of intersection, cross seas which are more or less dangerous, according as they are met with in advance or behind the hurricane. As the cyclone advances, a series of undulations are thrown off to the right and left, which flow in the direction of the two radii of the storm, dividing its semi- circles into quadrants. It is easy to see that these undulations fringe the storm's wake, they are found in fact to the right and left of the path which the storm has described. 31. In the left-hand or port semi-circle, in the northern hemisphere, and in the right-hand or starboard semi-circle, in the southern, a sea is given off which meets the undulations flowing to the right and left of the storm's path, and produces in the left-hand side of the storm's wake, in the northern hemisphere, and in the right-hand side, in the southern When this cross hemisphere, a tremendous pyramidal sea. turbulent sea is encountered, it is a pretty sure indication that the storm itself has passed the locality. A few examples in the southern hemisphere, will illustrate the effect of the cross seas, according as they are met with, in advance, or on the right or left hand of the storm's path. 32. A vessel in the Indian Ocean meets with a cyclone wind at S. heralded by the significant meteorological signs, characterizing the approach of a hurricane, but has not experienced any remarkable disturbance of the nature of a cross sea. This is a very dangerous position, inasmuch that if the commander depend on the appearance of the sea, as an indication of the proximity of a hurricane; he may here be greatly mistaken. The wind, its hauling and meteorological accompaniments, are sure indications of the presence of a cyclone; and it may be added, that the absence of a cross sea is also an indication of the vessel being on the confines of the most dangerous octant. Another vessel with the wind at N.W., experiences a mighty hubbub, she is involved in a turbulent pyramidal cross sea, and this is the greatest difficulty she has to encounter, the cyclone is leaving her in its wake, which is characterized on the starboard side, by a "heavy cross sea." A third vessel experiences the easterly winds of a cyclone, free from a turbulent cross sea. As the wind veers to E.N.E. the cross sea overtakes her, and if she continue in the wake of the hurricane, she will continue to experience the cross sea, but not to the extent that a vessel in the starboard or opposite side of the wake will. QUESTIONS To be answered by Commanders of Steam Vessels under! examination in the practical use of the Steam Engine.! Explain the nature and use of the principal valves and cocks connected with the boilers and engines, commencing with the boilers, 1. If the safety valves were set fast, how would you relieve the pressure on the boilers, if steam was up and could not make its escape? 2. How do you ascertain the saltness of the water in the boilers? 3. How would you manage to change the water in the boilers, if the blowoff cocks were set fast? 4. On examining the boilers, and they are found to be thin, what measures would you adopt to prevent accidents? 5. How would you keep the boiler free from salt and incrustation? 6. Is it requisite to have a hand-pump fitted to the boilers; if so, for what purpose. 7. Explain the use of the gauge-glasses and gauge-cocks, fitted on the boilers. 8. If the mercury was blown out of the steam gauge by the pressure of steam in the boilers; what would you apprehend was the cause? 9. What would you do to relieve the pressure of the boilers? 10. How would you regulate the height or quantity of water in the boilers? 11. When the steam is up, how is the feed applied to the boilers? 12 lighted? When it is not up, what is necessary to be done before the fires are 13. When the engines are stopped, what precautions are necessary with regard to the water in the boiler? 14. What is meant by a boiler priming? 15. How would you prevent it doing so? 16. If the water in a boiler is suffered to get too low, what may be the consequences? 17. What height should the water stand in a common boiler above the flues? 18. What height should the water stand in a tubular boiler above the tubes? 19. If any of the tubes were damaged by the fire or leaky, what would you do, supposing you could not shift them? 20. How do you detect the pressure of steam in a boiler? 21. If the water in a boiler is suffered to get too high, what might be the consequences? 22. How would you know when the water in the boiler requires changing? 23. Explain the use of the thermometer and bydrometer. Engines. 24. Explain the use of the cylinders. 34. Explain the use of the barometer. 35. Explain the use of the steam gauge. 36. The vessel is alongside the wharf, proceed to get the steam up. 37. When the steam is up, how is it applied to the engines to set it in motion ? 38. What precaution is necessary before the engine is set in motion? 39. How do you start the engine? 40. Is it necessary to move the engines by hand a turn or two before starting? 41. The engines being started, regulate the injection-cocks so as to keep them going at full or reduced speed. 42. What is the use of the injection? 43. How is the vacuum maintained in a condensing engine? 44. How do you know when there is too much injection ? 45. How do you know when there is not enough injection? 46. If the injection was not shut off when the engines are stopped, what would happen? 47. If the condenser reject the injection, what would you do? 48. Would it be advantageous if an injection-pipe was fitted so as to take injection from the bilge, if required ? 49. If water should get into the cylinder, what might be the consequences? 50. In running free with a heavy sea, and a jump upon the engines, what precautions would you take to endeavour to prevent damage to the engines? 51. If one engine was damaged, what would you do in order to proceed? 52. If the excentric should break, could the engines still be worked? 53. If a bearing becomes heated, what would you do? 54. How would you slow an engine? 55. How would you stop an engine? 56. Wherein does a high-pressure differ from a low-pressure engine? 57 How do you admit tallow into the cylinders, when the engines are at work, for the purpose of lubricating the pistons ? 58. What is meant by working the engines expansively? 59. How would you disconnect the engines if there was no disconnecting gear fitted? 60. What is meant by throwing the engines out of gear? 61. Why have two feed-pumps fitted, say one to each engine? 62. Is it requisite to have branch-pipes fitted to the feed-pumps; if so, for what purpose? The Engineer Examiner should provide drawings and working sections, on a sufficiently large scale, of the various parts of the steam-engine, and of the |