Explanation:--This is a cheap and simple but scientific apparatus for regulating the air-vent of a common, cheap stove, according to the temperature of the atmosphere in the room in which it is located. The draught door is a plain iron door, hung by a common hinge joint at the upper end; and to the front of the hinge is attached a piece of brass wire, which extends vertically nearly to the top of the room, and is connected at B to a horizontal brass wire C D. This is the only apparatus required, but must be so adjusted as to allow the door to be closed, or nearly so, when the temperature is about right. If the temperature rises above that point, the horizontal wire will immediately expand so as to allow the door to close. But as soon as the temperature begins to fail, the wire contracts and opens the vent. On this principle the apparatus will readily find a medium, and there remain, varying only occasionally to accommodate itself to the variations of the quantity of fuel in the stove. The entire expense of this apparatus, exclusive of the stove, will not exceed 50 cents. It is generally conceded that a large portion of cases of colds, coughs, &c. are occasioned by irregularities of the temperature of sitting-rooms but with this plan of regulation this evil may be avoided without any material expense. =New Paper Mill.= Mr. C. C. P. Moses has erected a line brick building, 75 by 38 feet, three stories high, on the site of the old foundry, at Dover, N. H., $12,000 to $15,000. The rooms are constructed and furnished in a complete manner for carrying on the paper making business in all its departments. The works are nearly completed, and will be in operation in five or six weeks. =New Mill at Lowell.= The Merrimack Company have in progress of erection the largest mill in Lowell, and which is calculated to employ from 300 to 400 operatives. The building is nearly finished, and the machinery is to embrace the latest improvements in this or any other country. =Machine Shop.= A new machine shop is about commencing operation in Norwich: about half a mile northeast from the railroad depot. The building is 100 by 40 feet, and is calculated to employ 60 hands in the manufacture of steam engines and manufacturing machinery. The work at this shop will be finished in the best style and at moderate prices. =Ornamental Kites.= [Illustration:]