The average ratio by weight, charcoal to wood, by Laboratory distillation,

The resulting ratio of increase of Pierce process over average practice in the above mentioned countries

The resulting ratio of increase of Pierce process over average practice in U.S.

The quantitative values of the products resulting from the destructive distillation of the wood by this process are as follows, based on the proportion of the several varieties before given :

The non-condensable gases are in excess of the amount required to effect the carbonization of the wood and about one-third of all produced are used for fuel under the boilers which produce steam for heating the alcohol stills, pumping water for the condensers, running the pyroligneous liquor pumps, the exhaust fans for the non-condensable gases and the winding engines for the cable incline cars used in raising the wood from the wharfboat to the kilns. This drawing off of a portion of the gas produced and its burning under boilers furnishes, together with the escape of kiln gases during seasoning, the necessary outlet to prevent the undue accumulation of the non-combustible gases arising from the combustion in the kiln furnaces and the carbonic dioxide driven off from the wood both of which would otherwise continually accumulate in the circulation system and ultimately choke the furnaces.

From the standpoint of industrial economics, the question of the economical production of charcoal in large quantities is one of importance, since the charcoal industry is extensive and the lines of possible improvement on the common practice are promising. These directions of improvement evidently consist:

1. In increasing the present yield of charcoal per cord of wood. 2. In improving the quality of the charcoal produced.

3. In utilizing to the best economy all of the available products of the

1 Experiments on same varieties of wood as are used in the Pierce process con. ducted by Stolze, Smith, Lattimore, Pierce, Aszmus and Hessel.

destructive distillation of the wood of which the charcoal alone represents in value only about 35 per cent.

The total production of charcoal in the United States in 1887 was very approximately sixty-five million bushels; of this amount only about ten million bushels were produced by the process herein described and it is safe to assume that the production of all other improved processes combined did not make the aggregate of all charcoal produced by improved methods more than thirteen million bushels, or one-fifth the total production; on this assumption the following table has been prepared showing the returns to be expected from the general introduction of processes for charcoal manufacture which should equal in efficiency the results hereinbefore given. (See table, page 151.) This table shows not only the amounts of the several by-products annually preserved but also the annual saving in cords of wood carbonized and acres of forest land annually denuded if the present demands for charcoal were met by improved instead of unimproved processes.

This paper has been prepared independently of any effect its publication may have on the process herein described' and wholly for the purpose of showing by citing and describing one existing successful improved process that the common practice of charcoal burning is extremely wasteful, and that, instead of obtaining only charcoal and that moderate both in quantity and quality, it is possible to so effect the carbonization of the wood as that it shall not only furnish an increased yield of superior charcoal, but shall in addition supply the necessary fuel to haul itself to the kiln, to carbonize itself, to circulate and condense its gases and evaporate its liquors and shall furnish valuable chemical by-products whose proceeds more than pay the entire cost of all attendant operations and leave the charcoal as a clear profit to be divided between the producer and the consumer. A reference to the appended table shows that the general introduction of improved processes for the production of charcoal sufficient to meet the present demands would result in a saving of over four hundred thousand cords of wood per annum, a reduction of thirteen thousand five hundred acres in the amount of forest lands annually denuded or the liberation for other purposes of over four hundred thousand acres of land were the total supply of charcoal furnished from permanent timber preserves, and the preservation of by-products worth, at the lowest possible valuation, four million dollars per annum.

1 The writer has no interest whatever either direct or indirect in the process herein described or in the publication of this paper which has been prepared without solicita. tion of any kind and solely from a belief that the account of the process might be of scientific interest.

TABLE SHOWING GAINS TO BE REALIZED BY THE GENERAL INTRODUCTION OF IMPROVED METHODS

FOR THE MANUFACTURE OF CHARCOAL.

No. of barrels of tar at ten gallons per cord......

None

52,000

260,000

52,000

260,000

No. of million of cubic feet non-condensable combustible gas

at 4000 feet per cord.........

None

1,040

5,200

1,040

5,200

ON THE INFLUENCE OF MOISTURE IN STEAM UPON THE STEAM CONSUMPTION PER LB. OF ENGINES OF LESS THAN FIFTY LBS.

J. E. DENTON, Stevens Institute, Hoboken, N. J.

[ABSTRACT.]

By. Prof.

THE paper describes an experiment with a 7 X 14 high speed engine in which water was injected into the steam pipe to the extent of about sixteen per cent of the total weight of steam used by the engine, and the resulting increase of steam consumption per lb. determined. It is shown that the increase in steam consumption was simply the water injected plus the latter's refrigerating effect in condensing steam with which it comes in contact.

The result indicates that the presence of moisture in steam does not induce a more uneconomical consumption of steam per lb. than is due to the amount of moisture itself; that is, does not increase the cylinder condensation of the engine, but further experiments are needed to establish a conclusion.

ON THE POSSIBILITY OF IDENTIFYING DRY OR SATURATED STEAM BY VISUAL OBSERVATION OF A JET OF SUCH STEAM FLOWING INTO THE AT

MOSPHERE. By Prof. J. E. DENTON, Stevens Institute, Hoboken, N. J. [ABSTRACT.]

THE paper describes an experiment in which a jet of steam flowing from a boiler at sixty pounds pressure into the atmosphere is superheated to a known degree, and then made to contain a known percentage of moisture by the abstraction of a known amount of heat from the jet.

Photographs were shown of the appearance of the jet of steam when the latter is dry, or slightly superheated, and when containing two and one-half per cent of moisture.

The conclusion reached is that as small an amount of moisture as one per cent causes a jet of steam to change in appearance to the naked eye so sensibly, that when a jet is perfectly transparent or invisible over a distance of about one inch from an orifice, which permits practically no wire drawing, it may be assumed that the moisture in the steam is less than one per cent.

RELATIVE ECONOMY OF HIGH SPEED ENGINES OF LESS THAN FIFTY LBS. USING STEAM BY EXPANSION AND THROTTLING RESPECTIVELY. By Prof. J. E. DENTON, Stevens Institute, Hoboken, N. J.

[ABSTRACT.]

THE paper gives the results of a series of experiments with a 7 X 14 high speed steam engine of the Buckeye type, whereby the steam consumption per horse power was determined for a large range of expansions at

variable cut-offs, and for a range of throttling at fixed cut-off. The experiments were conducted so that the same effective horse power was obtained at ninety pounds boiler pressure and a speed of 265-284 revolutions per minute: (1) By expansion without the use of a condenser; (2) By expansion and the use of a condenser to produce eighteen inches of vacuum; (3) By throttling without a condenser; and (4) By throttling with 18'

vacuum.

Diagrams and tables showing the results obtained were shown. The conclusions reached are:

1. That for ratios of expansion between one and one-half and seven, there is but little variation of steam consumption per horse power.

2. That the use of a condenser reduces the steam consumption of the engine per horse power for all practical expansions.

3. That "throttling" results in a considerable loss of economy.

EFFECT OF FRICTION AT THE CONNECTING ROD BEARINGS ON THE FORCES TRANSMITTED. By Prof. D. S. JACOBUS, Stevens Institute, Hoboken, New Jersey.

[ABSTRACT.]

LET Pw and Pe be the pressures of the wrist and crank pins upon the rod for frictionless pins; Pwr and Per the same when there is friction; rw and re the radii of the wrist and crank pins; R the length of the crank; nR the length of the connecting rod and tan the coëfficient of friction. Friction displaces the forces which the pins exert upon the rod, so that they are tangent to circles respectively equal to rw sing and re sin y. These forces will exert moments upon the rod tending to rotate it and therefore affect all the other forces of the system, so that the forces Pw and Pe become Pwr and Per and are altered from their original line of action. By a well-known principle in mechanics a force applied at any point is equivalent to an equal force in magnitude and direction at any other point plus a moment equal to the force multiplied by the perpendicular distance through which it has been displaced. We may therefore suppose the forces Pwr and Per to be applied at the centres of the pins if at the same time we introduce the moments Pwr rw sin and Per re sin y.

For convenience we will suppose each moment to be produced by a pair of equal and opposite forces acting perpendicular to the rod at the centres of the pins; calling these forces A and B we shall have:

Now instead of supposing Pwr and Per to act in a line tangent to the circles r sin and re sin y no error will be involved in determining the