zens have every reason to demand and to bring pressure to bear that the process be accelerated because of health, welfare, comfort and the things which make for civic betterment.

THREE WAYS TO MAKE SMOKE PREVENTION WORK MORE EFFECTIVE.

It may not be out of place at this point to make three suggestions as to how this acceleration may be brought about:

The first one is that a city administration should take an active interest in the smoke problem. It is not outside of its duty nor beneath its dignity to do so. The interest should take the form of constructive suggestion and encouragement, not a contemptuous tolerance of the bureau, pernicious interference on behalf of favorite offenders or the sending out of the edict "go easy." Any municipal activity breaks down at the point where favoritism enters. Unfortunately it is sometimes true that the smoke inspector does not secure more co-operation from the city administration because he, himself, does not take the proper attitude on the smoke problem.

He often thinks that his is somehow a hopeless and thankless job and the best he can do is to let "bad enough" alone. The smoke problem calls for broad men, men who have a sound fundamental training, men of imagination and men of force.

The second suggestion is that a city should know what its problem is. This may sound foolish, but there are not more than two cities in this country which have the information on which to base a serious campaign against the smoke nuisance. A city should know what its coal consumption is and its relation to the smoke problem. It should have exact knowledge as to the general sources of smoke and a good idea of the amount of smoke made by each source. It should know the location of all stacks and have all significant data on the kinds of installation under them. It should place special emphasis on securing facts

as to the ability of the different installations to abate smoke. It should spare no expense to secure evidence with which to convince the most hardened offender of the smoke ordinance that the emission of dense smoke is both wasteful and harmful.

The third suggestion is that with such information a city should diagnose its problem and plan broadly and deeply for its solution. For this purpose the ordinance should be studied to find out whether or not it was simply copied from that of another city or was adapted to the problem at hand. It should decide how much emphasis is to be placed on the abatement of smoke and how much on the prevention of future smoke. The organization of the smoke department should be worked out with reference to the extent and nature of the problem. If it is possible, the smoke bureau should be separated from other activities and set off by itself. This will give to it dignity, obtain for it the proper attention and concentrate responsibility.

Above all, plans should be laid to secure the co-operation of all civic and commercial organizations and institutions of learning that a solid front may be presented in attacking the smoke problem. This is important, whether the plan of procedure is to be one of education or prosecution. No municipal activity in this country is developed sufficiently to reach its goal without the help of organizations which have the welfare of the community at heart. The assistance, the criticism and the approval of civic organizations should be sought after and prized. Institutions of learning in which reside the sciences which have solved so many municipal problems should be recruited for the fight. and the students of engineering schools should be impressed with the necessity of giving attention to problems of combustion. All the forces that are in a community should be called into action to help to solve one of the most difficult problems which confront municipalities.

To summarize: Most of our civic problems are problems of industry problems concerned with our very exist ence. The smoke problem is such a one, and for that reason, if for no other, is difficult to solve. Cities are coming to take an increased interest in it. This is due to the fact that points in the indictment of the smoke nuisance have been impressed upon them with new force. Cities have come to know that

the smoke nuisance is harmful and wasteful, and that smoke abatement is practicable. Cities with well-organized smoke abatement departments which have the support and interest of city administrations, cities which know the problem before them and which have planned broadly and deeply for its solution have every reason to look forward to "Noble and joyous cities, unbelievably white."

Fuel economy is being forced on the American people by the constantly advancing price for all kinds of fuel. At the present time, war conditions have unsettled prices of almost every commodity, including the various fuels; but when conditions are normal, soft coal is the cheapest fuel on this continent. It occurs in almost every State and territory, while hard coal is limited to a comparatively small area of one state only.

The comparative prices of soft and hard coals vary for different localities. In some States soft coal sells for about half the price of hard coal. In other States the price asked for one ton of hard coal will buy three or four tons of the local soft coal.

RELATIVE HEATING VALUES OF HARD AND SOFT COAL.

The relative heating values of hard and soft coal are not well understood by the general public. The majority of the people believe that for heating purposes two and one-half to three tons of hard coal are equal to five tons of soft coal. Then again, many coal buyers are under the impression that the coal showing by analysis the highest heat content is the most valuable coal for any kind of heating purpose.

suppositions is correct.

Although the United States Government has analyzed a great many varieties of coal, both soft and hard, and given the same to the public through official bulletins, yet in none of those bulletins can the user find any data that will indicate the burning characteristics of soft coal.

If we are selecting a hard coal by analysis we try to get a coal with a high heat content and a low ash. But when it comes to selecting soft coals by analysis, the problem is more complicated.

BEST GRADES OF SOFT COAL LIKELY TO CAKE.

If we select for heating purposes a soft coal of the highest calorific power or heat content and low ash, we are likely to have a hard caking coal that fuses and makes into a hard mass, making the stoking a difficult and disagreeable task.

In some types of boilers this hard caking variety will be almost unburnable. The heat content of the eastern soft coal equals, and for some varieties exceeds the proximate analyses of the best hard coal. The western soft coals run from 10% to 20% lower in heat content than is found in eastern soft coals.

Notwithstanding this, the western soft

down-draft and special soft coal boilers than are the eastern coals. This is so because many of the western coals are semi-caking; that is, the coal does not fuse and run together under heat as readily or bake so hard as do some of the eastern coals, and for this reason less stoking is necessary. In burning soft coal in up-draft boilers the caking coal is preferable for the reason that the coal fuses at comparatively low temperatures, forming a crust in the upper fuel mass which prevents the escape of the volatile gas. This gas is thus forced to the sides of the firepot, where it forms an intimate mixture with the oxygen, ignites and becomes useful heat.

When free-burning or semi-caking coal is burned in up-draft boilers the volatile gases which constitute from 30% to 40% of the total heat content escape through the upper strata of coal unignited and become a total heat loss.

In boilers especially designed to burn soft coals these volatile gases burn to useful heat, and for this reason a semicaking coal is better adapted for burning in the modern soft coal boiler than are the strong caking varieties.

In selecting soft coal to burn in specially-designed soft coal boilers it is advisable to select one with a high volatile gas content, as this item indicates a freeburning or semi-caking coal. The heat content of a typical western coal will run about as follows:

in volatile matter, about 16% being a fair average, and, as is well known, these coals require a great deal of stoking because of their strong caking qualities. A very free burning coal is mined in Ohio which burns as freely as charcoal. The volatile gas content in this coal runs about 46%.

Broadly speaking, the difference in the cost of heating with soft coal as against hard coal is the difference in the cost

per ton. The exceptions are for the lignite and sub-bituminous which are low. in heat content.

There are many who object to using soft coal, for various reasons, but chiefly because of the smoke and soot accumulations. A properly-constructed soft coal boiler will eliminate these two objections.

WHY PEA COAL SAVES MORE THAN THE DIFFERENCE IN PRICE.

A valuable hard coal product is pea coal when burned in boilers specially constructed for same. While pea coal at the present time costs within a dollar of the price of stove coal, yet where it is burned in place of stove coal the saving is very much greater than is indicated by the difference in price. This is so because in practice 90% of fuel waste is due to burning fuel in excess of requirements. When pea coal is burned its density prevents runaway fires, and for this reason it is an excellent draft stabilizer.

There are many instances on record where the change from stove coal burned in an up-draft boiler to pea coal burned in a specially-designed magazine boiler has effected savings as high as 40%. while the difference in price of the two sizes does not represent at the present time more than 15% or 20%.

Pea coal is easily and cleanly handled, and when burned in the right kind of boiler there is no clinker. It is too dense to burn in up-draft boilers unless mixed with a coarser coal or with broken coke.

the lower buildings, when the wind is from the higher point.

Fig. 2 is a representation of a series. of tests on a chimney and is very accurate, showing the velocities at different points in the chimney, which is a hexagon shape and 110 ft. high. Compared with chimneys of the same area, round or square, the difference is so slight that it is scarcely noticeable, and is shown for the purpose of recommending that if a stack has the height and area, its shape is not a feature to condemn the chimney. Of course, a round chimney is preferable in all cases, but is not absolutely necessary. However, height and area are absolutely necessary. Breechings and breeching connections

are

As

Re-constucted

PLAN

As Re-constructed

ELEVATION

FIG. 3-CHANGES MADE IN SMOKE BREECHING TO REMEDY POOR CONDITIONS.

neys that are in the wrong place. If the chimney is such that it strikes the center line of the boiler, it should be connected to one end or the other of the

boiler by curved breeching. The correct way of setting this, however, would be to either have the chimney at the front or rear of the boiler, lessening the length of breeching run. The elevation shows the kind of connection that should be at the rear or front, and in no case should it be connected with the center line of the boiler. The damper shown in the front connection on the elevation plan is wrong, because when it is wide open the opening is half closed. It should be placed at the side of the boiler shown in the plan section. If at the rear, it should be made as shown in the rear. It doesn't cost any more; is always available for doing its duty, and doesn't interfere with other boilers connected on the same run of breeching. If the breeching is carried across the top, the damper should be made as shown in

the small cross section to the right of the figure. This will not interfere with the gases from any other boiler, and when open, dampers built after this manner will allow the pull of the stack to begin at the boiler, instead of meeting resistance offered by a wrong construction which reduces the size of the original opening, and prevents the stack from delivering the air to the furnace that it would or should deliver.

Fig. 5 shows the damper opening usually found in horizontal tubular boilers, and though it may have the proper area, it forms a contraction and resistance to the gases due to its shape, which should be as shown in Fig. 6.

Fig. 6 shows the opening of the damper extending the entire distance across the boiler, and allowing the free passage of the gases over more heating surface than is allowed in Fig. 5, while less resistance is offered to the flow of the gases at this point. In all settings where the free flow of gases is required, there is nothing gained by having the construction so that pockets are formed within the setting, preventing the free circulation of the gases around the heating surface. If the draft is too strong,