Hogg's Patent conical Boiler. 297 



(luce the prime cost of these articles very considerably. Without 

 any pretensions to give an accurate description of this machine, 

 which could not be done without drawings, it may suffice to say 

 that the clay is conveyed from the pug-mill to the machine, 

 where, by passing between cylinders and moving over moulds, a 

 tile of perfect consistency and proper dimensions is formed, and 

 conveyed along to the drying shed, without the intervention of 

 manual labour. Several of these machines are now in full ope- 

 ration ; and, with the attendance of one man and two boys, 

 10,000 tiles are easily formed and placed in the drying sheds in 

 one day. If the duty were reduced on large-sized bricks it would 

 add much to the cheapness, strength, and beauty of brick build- 

 ing generally. How easy would it be to form excellent coping 

 for garden walls, edgings for gravel walks, movable walls for the 

 protection of early potatoes, peas, &c., and paving for fruit-tree 

 borders, and for training fruit-trees near the surface of the ground. 

 East Lothian^ May 26. 1837. 



Art. IV. Description of Hogg's Patent conical Boiler, for heating 

 Hot-houses, and other Buildings, by hot Water. By James Hogg, 

 New York, United States. 



I FORWARD to you two skctchcs of a boiler invented by my 

 brother, now residing in New York, who is but eighteen years 

 of age, and who, as I was coming on a visit to this country, de- 

 sired me to give j'ou a description of it, for insertion in the 

 Gardener's Magazine. 



The boiler is intended for burning anthracite coal (which is 

 now most generally used in the United States) or coke. An- 

 thracite coal gives out a most intense heat, but it is not diffusive 

 enough in a flue, as it has no smoke, and very little flame ; and, 

 consequently, owing to the severity of the American winters, we 

 are obliged to use great quantities of it, which causes much wear 

 and tear of the furnaces, which generally want repairing every 

 season, and resetting at least every two years. To obviate this 

 expense, and to do away with the trouble of attending flues, my 

 brother, from a hint given him by my father, invented the boiler 

 above described. Its principal merit is, that there is very little 

 loss of heat, nearly all of it being absorbed by the water which 

 passes round the pipes and furnace. The outside, being of strong 

 oak staves, is much cheaper than iron, and nearly as durable ; 

 and there is no leakage, warping, or danger from fire, as the 

 furnace is raised, by means of the ring, at least two inches above 

 the iron plate. 



Fig. 104. is a section of the boiler, which consists of a conical 

 iron furnace a <?, with the two pipes /; and r, and the flanges d /-/, 



