144 ON THE SETTING OF STEAM BOILERS. 



had to do witli a Laiicashiro boiler, which I originally set 

 on this system. It is 2.5 ft. long, fi ft. G in. diam., 2 fines 

 each 2 ft. 6 in. diam., crossed hy galloway tubes. The pros- 

 sure is 60 to 05 lbs., and the ordinary duty obtained, witl.- 

 out forcing, from Somerset slack, in a compound engine 

 with no expansion valve and unjacketod, is 116 I.H.P. I 

 am quite sure this boiler would not give anything like such 

 a result if set in the ordinary way. 



One other important advantage of the system is, that 

 economizers may be dispensed with. They present a great 

 obstacle in the way of the draught, and, to be of any use, 

 the temperature of the gases must be kejit very high in the 

 flue after leaving the boiler. In the Manchester Exhibi- 

 tion the feed-water was raised 18(J^ by an economizer, and 

 the temperature of the issuing g.ases was reduced 300° in 

 raising it. As they would not be likely to enter the 

 drimnoy at loss than 300°, they must have issued from 

 the boiler flues at not less than (JOO". It must bo, there- 

 fore, much better to get the heat direct into the water 

 first-hand, than to let it pass the boiler, and then put 

 in a most expensive arrangement of pipes, witli automatic 

 scrapers and driving shafts, etc., in order to collect and 

 ultilize that which ought never to have escaped. All such 

 contrivances require additional chimney height to i)vdl the 

 gases through, while with tlio largest boilers on livct's 

 system, a chimney of seventy feet in height is ample. Many 

 30 ft. boilers are working with the best results witli only 

 sixty feet chimneys. This is not one of tlio least of the 

 advantages claimed for this system, as many firms can testify 

 who have had sufficient confidence in M. Livet's assurances 

 to put them to the proof, and who have found it Avas just as 

 well to keep £500 or £1,000 in their baidi as to spend it upon 

 useless bricjks and mortar. 



