1870.] WEEKS' UPRIGHT TUBULAR BOILER. 



369 



its kind that has ever been brought to the notice of the horticultural 

 world, and in all the attempts to bring it into action, it has answered 

 far beyond their most sanguine expectations. Its durability is one 

 special feature, and the patentees are prepared to guarantee and insure 

 by policy its usefulness and safety for a space of 15 years. 



Absolute exemption from failure is also claimed for it on the ground 

 that it is constructed in two halves ; the construction and expansion are 

 entirely neutralised ; and should any unforeseen accident occur to one 

 half, that portion may be detached and removed, without in any way 



interfering with the working of the other half. Thus it is termed 

 " indestructible." The shutting-off of either half from active work 

 is accomplished by means of an improved gun-metal screw, valves 

 and chambers. 



The arrangements for removing sediment are so perfect and simple, 

 that any ordinary labourer may clean out the boiler at any time by 

 drawing the water from the apparatus, or removing a single brick in 

 the furnace. This is stated to be an advantage no other boiler used 

 for horticultural purposes can lay claim to. The boiler being con- 



2 a 



