CIRCULATING PIPES, DAMPERS, &c. 19 



It has sometimes occurred that boilers of good construction have suddenly failed in 

 generating the necessary quantity of steam for the engines, although the fires have been urged 

 as usual : this unaccountable circumstance, after the strictest investigation, has been cleared 

 up by the appearance of steam at the top of the chimney, instead of at the waste steam head. 

 The UPTAKE, or portion of the flue which rises through the water of the boilers to join 

 the chimney, has been found defective, so that the steam escaped above the water line, through 

 the rent it made, directly into the funnel or chimney, the boilers in every other respect 

 performing their duty properly : the uptake, therefore, should be thicker than the other 

 portion of the flue, and should at frequent opportunities be perfectly cleaned and coated 

 with some anti-corrosive : coal tar mixed with red lead, and applied hot, I should 

 recommend. 



The SHELL OR CROWN of the boiler, and STEAM CHEST, suffer most from accumulation of 

 dirt, and leakage from above. Steam vessels are necessarily much more subject to be extremely 

 dirty than other vessels ; in fact, it is periodical every sixth or seventh day on foreign service, 

 and sometimes oftener, to be completely covered with coal dust in every part exposed. Water is, 

 and can never be entirely prevented from being, thrown over every part of the ship : it is this, 

 and the every-day work of dashing water over the decks, that achieves the destruction of the 

 parts above mentioned, more than any other cause ; the rain and spray certainly assist. Hence 

 too much care cannot be taken in rendering every part of the deck, or other covering of the 

 boilers, as tight as possible. Waste and feed pipes rather interfere ; but they can be, and are 

 generally fitted now, beneath the deck, so as to be entirely out of the way of accident, in case 

 the funnel be carried away. 



The AIR CASING around the base of the funnel, in most vessels in Her Majesty's service, has 

 been surmounted by a hood water-tight, so as to prevent the water passing in that direction com- 

 pletely, the flanch of the casing being made tight on deck; and the bottom cants of the coal- 

 boxes are fixed two or three inches clear of the sides of the boilers, so as to permit dirt, which 

 may not be intercepted by the pieces of wood, fitted between the crown and the coal-boxes fore 

 and aft for that purpose, to be washed into the ship's bottom, whence it can be removed, thus 

 preventing its accumulation between the coal-boxes and the boiler sides. If it could be 

 afforded, sufficient space should be allowed for a passage around the boilers, by which they 

 may be kept perfectly clean. 



As little wood as possible should be used around the upper parts of boilers, in addition to 

 the covering of the deck. Thin sheet iron, properly riveted and chinced, should take the place 

 of comings, &c. which, with the carlines which support them, are frequently set on fire. Coals 

 and wood, not directly in contact with the air casing, have often been fired in a very short 

 space of time on deck when exposed, as likewise when contained in bags in the same situation. 

 More than one air casing should invariably be fitted around the funnels of sea-going steam 

 vessels, the air freely passing between them, so as not only to remove the risk of fire in a great 

 measure, but also the oppressive heat which is experienced in still weather in warm climates, 

 when passing or standing in the neighbourhood of the same. The outer casing, whenever the 

 construction of boiler will permit, should have a large flanch fitted on deck, which should be 

 cut round as far as possible from the casing, the flanch being made perfectly tight, which can 

 never be attained by the pitch and oakum joints of comings, or the hatches or platforms they 

 support. Corrugated iron, is a neat substitute for wood to surround the parts of boilers 



