WATER TUBE BOILERS. 



Appendix No. I — continued. 



611 



During these trials a log book was kept, in which records were 

 entered at least once every fifteen minutes. The weighbridge on 

 which everything was weighed was by Avery, and accurately tested. 

 The thermometer was also accurately calibrated. The pyrometer 

 was by Bailey ; it has not yet been tested ; when it was reading 

 1300°, Fahr., it was examined and found to be a dull cherry red; 

 hence it is probably nearly correct for high temperatures. Calori- 

 meter readings were taken in a barrel of about 40galls. capacity, and 

 the temperature of the steam was taken from the steam pipe leading 

 to the steam engine. Unfortunately the connecting nipple was so 

 placed thai it rapidly filled with condensed water, and consequently 

 the reading was certainly below the true temperature of the steam. 

 The engine was by Marshall, but was not only of an old type, but 

 had very poor steam connections so that quite 40 per cent, of 

 the steam was wasted. All the coal used was carefully weighed 

 by two observers, and the water was measured by two accurately 

 proportioned tanks. The trials were of an exceptionally severe 

 nature (similar to those carried out by Sir Frederick Bramwell and 

 Sir William Anderson for the Royal Agricultural Society in Eng- 

 land), the fuel being raked out of both grate and ash pit before 

 and after each trial, so that the record began with clean bars and 

 left off under the same condition. It is not easy to get any record 



