IIKATINO APPARATUS. 363 



CHAPTER XXVII. 



HEATING APPARATUS MARINE STEAM-ENGINES REFORM COLUMN. 



" LAUDERDALE HOUSE, HIGHGATE, 

 " MR. GILBERT, " March 1st, 1830. 



" Sir, I have to apologize for my neglect in not calling 

 on you, but ill-health prevented it. I left home on the llth 

 February, arrived in town on the 14th, and remained there 

 until the 24th, when I was compelled to leave for this place, 

 having a free good air. I am now taking, twice a day, the 

 flowers of zinc, from which I hope to be soon right again. I 

 am much better, but afraid to enter the city. I hope to be 

 able to call on you before the end of this week, being very 

 anxious to see you, having a great deal to communicate re- 

 specting the experiments I have been making, which will bear 

 out to the full our expectations. 



"Your hot-house apparatus has been finished nearly three 

 months, all but two or three days' work to fit the parts to- 

 gether ; I expect that before this they are in Penzance, waiting 

 a ship for London. While making a sketch of your work for 

 the founder, a thought struck me that rooms might be better 

 heated by hot water than by either steam or fire, and I send to 

 you my thoughts on it, with a sketch for your consideration. 

 I find that steam-pipes applied to heat cotton factories, with 

 1 surface foot of steam-pipe, heat 200 cubic feet of space to 

 60 degrees. I also found in Germany, where all the rooms 

 are heated by cast-iron pipes about the heat of steam, that 

 1 foot of external flue heated 160 cubic feet of space to 

 70 degrees. 



"I find also that about 200 surface feet of steam-engine 

 cylinder-case will condense about as much steam as will pro- 

 duce 15 gallons of water per hour, and will consume about 

 4 bushels in twenty-four hours to keep the temperature of 



