208 THE POPULAR SCIENCE MONTHLY. 



labor, and in the supply of a community with goods, has succeeded to 

 an encouraging extent in Europe, and in some degree on this continent. 



In domestic life, also, the burden of sustaining the usual isolated 

 homes is beginning to be thought grievous and unnecessary. The 

 constant repetition of the same details on a small scale, in cooking, 

 warming, and attendance, is evidently subject to a large discount in 

 cost, and increase of comfort, when a number of families combine to 

 have a single kitchen, heating-furnace, and corps of servants. ]\Iany 

 solutions of this problem have been attempted with various success ; 

 large houses rented in fiats, copied from European models, adorn some 

 of the chief streets of New York and Boston, and hotels on all sorts 

 of systems are to be found in our principal cities, numbering among 

 their patrons thousands of families. It may be reasonably expected 

 that in the near future some plan will be arrived at, and widely 

 accepted, combining the benefits of individual homes with the advan- 

 tages of association ; but, for this result, an improvement in our pres- 

 ent crudcness of social feelings must take place. Great is the pre- 

 mium placed on the growth of mutual harmony and confidence, yet 

 how slow that growth is ! 



A process analogous to aggregation is that of concentration, which 

 marks many of the forms of progress. When a force operates against 

 a lesser one of eonstant amount, concentration multiplies its efficiency. 



If a common furnace's heat is 3,500, and a temperature of say 

 3,000 is required to melt iron, then but 500 of 3,500 are available 

 for that pitrpose ; but, when the same quantity of heat is presented at 

 4,200, 1,200 of 4,200 may be utilized, an efficiency twice as great 

 as the former. Hence the value of such an invention as the hot-blast, 

 increasing the intensity of flame : the inert and diluting nitrogen is 

 mingled with the oxygen of common air by the feeble force of diffu- 

 sion ; if they could be cheaply separated, it would mightily enhance 

 the value of coal. Steam-engines, as now constructed, rarely yield 

 in work more than a tenth the equivalent of heat applied; the chief 

 waste" is in the exhaust-steam, which, although in immense quantity, 

 is of too low a temperature to raise more steam. Any feasible plan 

 of concentration is all that is wanted to make the steam-engine more 

 powerful ; its duty has already been nearly doubled by the use of 

 much higher pressures than Watt employed or sanctioned. A pebble 

 on a sea-beach may have been exposed to the sun for ages without 

 perceptible effect, but the focusing of a lens may reduce it to the 

 liquid state in a few moments with no more solar beams than might 

 have otherwise idly fallen upon it in an hour. This same principle 

 also obtains in the operations of trade and business: the expenses of 

 a railroad, steamship, or hotel, are pretty constant, and a certain 

 amount of patronage pays them ; beyond this point profits rapidly 

 accumulate, and below it so do losses; small fluctuations produce 

 large results in the balance-sheet. 



