SCIENCE. 



373 



sugar dealer has just told me " some of these establish- 

 ments turn out five hundred barrels daily." 



From the best information I can get, I would place 

 the daily yield of mixed sugars at 1500 to 2000 barrels. 

 This, remember, is only a careful estimate from all the 

 data I cm get. The process is incteasing just as fast as 

 dry white grape sugar can be made. 



With regard to table syrup, I can only reiterate my 

 former statements. In response to a recent inquiry a 

 prominent dealer has just written me as follows : 



" My observation leads me to believe that fully four- 

 fifths of all the syrup sold throughout the western and 

 northwestern States and Territories are composed of 

 glucose, with enough cane syrup or m( lasses added to 

 give it the color most desirable to the buyer or con- 

 sumer." 



I have no accurate information respecting the eastern 

 trade. I am not without a suspicion, however, from the 

 appearance of some syrups which I have lately seen on 

 Boston tables, that the beautiful svrup made from the corn 

 of our western prairies, has invaded the very stronghold 

 of the dirty refuse syrups of the sugar refineries. 

 Respectfully, 



H. W. Wiley. 



Boston, July 27, 1881. 



WATER AS FUEL. 

 To the Editor of "Science " : 



I am interested in the paper of Dr. Rachel, in " Sci- 

 ence," July 9, on the use of water in combustion. 



The subject is a most important one ; and I regret a 

 mistake which a reader might fall into from an inadver- 

 tency, I suppose, in not more clearly distinguishing 

 between the degrees of temperature at which the trans- 

 fer of oxygen takes phce from the hydrogen of the water 

 to the carbon set free by the dissociation of the naphtha, 

 and the number of heat units set free or absorbed by 

 such transfer, which is a very different thing. 



It is not a case of the dissociation of water, but of the 

 dissociation of naphtha, and the transfer of oxygen 

 from the hydrogen to the carbon so set free ; a carbon 

 which was very loosely held by the hydrogen in naphtha. 



It is only a trade of so much carbon for so much 

 hydrogen ; the absolute heat of which, according to 

 authorities, are almost exactly equal in complete burning. 



But while the trade is thus equal in absolute heat, 

 there is practically an enormous gam ; and it is very im- 

 portant to see just what it is. 



We get our heat all in hydrogen instead of in carbon, 

 and so a.oid the enormous prac ical lcsses which attend 

 the usual mode of burning carbon. v 



We get our heat in hydrogen, which is the easiest of 

 all things to get all of it out by burning, instead of in 

 carbon which is one of the hardest of all things to get it 

 all out of, the difference being much like that between 

 the ease of getting our money out of a bank or out of a 

 lot of debts where from half to three-fourths or nine- 

 tenths is almost always finally lost. 



The practical man does not understand very well what 

 it means when he is told that the use of coal under boilcs 

 only produces five per cent of its energy in work. It 

 means this : that a series of enormous losses is made 

 in trying to get the heat out of the carbon in burning. 

 An enormous quantity goes off as black smoke and soot, 

 not burned. An enormous quantity goes off as carbonic 

 oxide, giving up only a third of its heat, instead of giving 

 it all up by burning to carbonic acid. An enormous quan- 

 tity of heat is lost in heating up the great quantity of 

 gases and air, that pass off without being fully burned, 

 which prevents a high temperature. An enormous quan- 

 tity of heat is carried up the chimney, because a little 

 coat of soot and ashes on the boiler does not allow it to 

 go into the boiler fast enough while passing so rapidly to 

 the chimney. Is it any wonder that an enormous revolu- 



tion is to be made by a mode of burning where water is 

 used not for any energy to be got out of it, but by which 

 the heat is taken from carbon, and put into hydrogen, 

 where it all flashes into usable form the instant the air 

 can reach it? Where the whole heat is liberated at one 

 point where it is wanted, instead of in a long, imperfect 

 flame ? Where there is not a particle of soot or dust to 

 tarnish the boiler and prevent the heat from passing into 

 it wherever it strikes ? And where the heat is nearly all 

 in that low form of invisible radiance which is best suited 

 to radiate on to, and be absorbed by, the boiler without 

 waiting for the heated gases to actually strike it to give 

 up their heat by slow convection ? 



It is a fact well known in the use of the alcohol and 

 gas flames, that if you want them for heating alone vou 

 want the non-luminous flame only ; because with a lum- 

 inous flame a large part of the heat is in the form of 

 light, which is not so readily absorbed by substances as 

 heat, as it is with the non-luminous flame ; and another 

 large part is held by the gases as convective heat, and 

 cannot so freely pass into substances by radiation, as in 

 the radiation from the non-luminous flame. 



Thus the revolution in combustion by the use of water 

 consists in transferring the heat from carbon to hydro- 

 gen, by which all the great losses of burning are avoided, 

 and the entire heat is obtained clean, without smoke, at 

 the exact point desired, and in the form which takes right 

 hold of the work without loss of time or energy. 



These things are of an incalculable value ; very 

 much better than any mysterious supposed increase of 

 heat from the water itself. 



Though it is important to form a non-luminous gas 

 by means of water to utilize the carbon, yet the water so 

 added takes up a share of the heat to raise its tempera- 

 ture along with the other gases, and so reduces the 

 temperature in proportion to its quantity. 



So, if we need high heats we must use the least quan- 

 tity of water, which will turn all the carbon into a suit- 

 able gas. 



If we add water enough to make the carbon of 100 

 pounds of naphtha into carbonic acid, it will take 250 

 pounds of water, if we assume that the naphtha aver- 

 ages a composition of C 6 H14, containing 84 pounds of 

 carbon and 16 pounds of hydrogen ; and the result would 

 be 30 pounds of hydrogen and 310 pounds of carbonic 

 acid. This would require 1530 pounds of air to burn it, 

 and produce 1880 pounds of gas, of which over one- 

 seventh would be due to the water, and the temperature 

 would be less than s of what it would have been with- 

 out, if an equally perfect burning could have been se- 

 cured without ; because the water, as steam, has about 

 twice the capacity for heat, as the other gases. 



If we only add enough water to make all the carbon 

 into carbonic oxide, it will take only half as much water; 

 125 pounds to 100 pounds of naphtha making about 

 one-thirteenth of the gas after burning ; and reducing the 

 temperature only one-seventh. 



But if we use only 36 pounds of water to 100 pounds 

 of naphtha, one gallon of water to four gallons of 

 naphtha, the gases may be something like this : 

 Marsh gas, CIIi, 80 pounds. 

 Carbonic oxide, CO, 56 pounds, 

 which with 1530 pounds of air (20,000 cubic feet) to 

 burn it, will make 1666 pounds of gas ; and the water 

 added will only reduce the temperature one-twenty-fifth 

 part, instead of so much as before. 



In each case the air to burn it, and the units of heat 

 produced, will be the same ; but the temperature will 

 vary with the proportion of water added, and, also, 

 with the quantity of unburned air passing through. 



One of the great advantages of the water process is the 

 condition of blast with which the fuel unites with the air, 

 by which the thorough mixture and burning is secured. 

 And it is very important that the quantity of air going 

 into the furnace be regulated so as to furnish only about 



