In regard to mixing

It is very desirable to put into a mixing at one time the cotton from several different bales, and is much to be preferred to the bale through, then another, and You can readily see that this cot

present custom of putting one so on, one bale after another.

ton which lies before us is in a very convenient form for a mixing of this sort.

It seems to me there is a great future in this bale.

DCCLXXXVI.*

EXTENSION OF THE STANDARD UNIFORM METHODS OF CONDUCTING AND REPORTING STEAM-ENGINE TESTS.

BY BRYAN DONKIN, LONDON, ENGLAND.

(Member of the Society.)

THIS subject has had considerable attention in the United States for many years, and valuable work has been done there, more so than in other countries. The writer considers that it is very desirable, and that the time is now ripe for the further dis. cussion of this important matter, and with this object he makes the following suggestions.

More uniformity in different countries could doubtless be obtained in the future by the adoption of such standard methods and by more combined action. Regulations of this kind would add to the comfort and ease of comparing steam-engine results of very different types in the United States and Europe. The American Society of Mechanical Engineers has for some years taken the lead in an excellent and practical way.

Steam Boilers, Locomotive and Pumping Engines. This Society has formulated methods and instructions to be used for testing, not only steam boilers, but also locomotive and waterpumping engines. This has raised the Society in the estimation of the engineering world wherever English is spoken. In France and Germany, however, little or nothing is known of the useful work which has been carried on, and steps should therefore, in the writer's opinion, be taken to make such methods more largely appreciated.

Marine and Factory Engines, etc.-Similar standard methods of conducting and reporting these experiments should, he suggests, be extended not only to the important branch of marine steam engines, but also to factory, mill, and agricultural engines, and quick-running steam motors for electrical work.

* Presented at the Niagara Falls meeting (June, 1898) of the American Society of Mechanical Engineers, and forming part of Yolume XIX. of the Transactions.

Rotary Engines.-Some notes might also be added to include the new types of steam road carriages and rotary fixed engines, since the efforts hitherto made to standardize trials relate chiefly to the reciprocating type of engine. At the same time, all the existing reports of your committees might perhaps be remodelled and made up to date.

Gas and Oil Motors.-It would also be well that a committee should be appointed by the Society not only to take into consideration the above questions, but also to standardize a uniform method of testing and reporting on gas and oil engines. These extremely economical motors give, as is well known, a very much greater heat efficiency than steam engines. They must, therefore, have a great future before them, and the sooner such methods of trial are published, the better for those who make the tests and those who have to compare them.

Blank Forms.-With regard to the blank forms for the different types of steam engines, the writer is of opinion that it would be better, and likely to cause less confusion, if they were kept quite separate and distinct. There should, he thinks, be different instructions for testing, first, land fixed engines; second, locomotive engines; third, marine engines; and fourth, water-pumping engines. Any engineer, even if not a member of the Society, should be in a position to purchase these blank sheets separately for his immediate use. One set should also be drawn up for steam boilers, and thus there might be in all five pamphlets, each embodying complete instructions. These five pamphlets could always be on sale at a moderate price for engineers, students, and others, and ready for any test. It would be best to have them printed on strong paper, in small book-form, pocket size, as reference to the bulky volumes of the Transactions is inconvenient, and taking copies of all blank forms very troublesome and liable to

error.

Another step, perhaps of equal importance, which the writer begs permission to suggest, is that the Society should have these forms and instructions translated into French and German, and adapted to the metric measurements of those countries. They could then be sent, if desired, to the most suitable institutions and societies in France, and also to those in Germany, Belgium, Russia, Austria, Switzerland, and Italy. If these societies have not already a standard method of making similar

trials, it might be suggested to them to constitute a committee to formulate similar standard methods for use in their own coun. tries. It would be desirable to add that, if possible, the same general order should be adhered to to facilitate comparisons of the different results in different countries. In this way we may, in a few years, hope to see some approach to uniformity in the records of tests in the different engineering centres throughout the world. In England the Council of the Institution of Civil Engineers, London, at the writer's suggestion, has taken the matter up, and the Thermal Efficiencies Committee (of which he is a member) will shortly issue their full report. Appendix I. (subjoined) gives their preliminary report, published in the spring of 1897.

Another committee has also, at the writer's suggestion, been lately appointed by the council of the same institution, for considering and reporting upon the best set of headings for standardizing steam engine and boiler experimental results. This committee has not yet issued any report nor held any meetings. The conclusion arrived at in the preliminary report of the Thermal Efficiencies Committee is that all steam and heat engine results should be given in thermal units per indicated horse-power and brake horse-power, and not in pounds of steam per indicated horse-power and brake horse-power only.

Dealing with so large a subject, no programme can ever be final, but will require revision every few years, as science advances, and better instruments are invented or brought

out.

The writer is very glad to see that Mr. Barrus, of Boston, and others, are advocating similar standards, and also adapting to modern requirements those already published by this Society.

In future, if the English and American standard result sheets for steam engines and boilers could be issued in the same general order, it would help to make the experiments and render comparisons easier.

At present there is no agreement amongst engineers as to the best standard for efficiencies of steam engines, in order to compare the results of any actual steam engines with those of an ideal engine. This difficult question has been discussed by the London Institution of Civil Engineers' Thermal Committee, and their report will be published shortly.

Appendix II. contains a few additional suggestions of less importance than those mentioned above, but upon which discussion by the Society is invited.

APPENDIX I.

PRELIMINARY REPORT OF THE COMMITTEE APPOINTED TO CONSIDER AND REPORT TO THE COUNCIL UPON THE DEFINITION OF A STANDARD OR STANDARDS OF THERMAL EFFICIENCY FOR STEAM

ENGINES. (LONDON INST. CIVIL ENGINEERS.)

Your committee beg leave to report that they have now practically come to an agreement on the subject of the reference to them, and that the draft report has been drawn up.

The conclusions to which they have come to are as follows:

(1) That the statement of the economy of a steam engine in terms of pounds of feed-water per indicated horse-power per hour, is undesirable.

(2) That for all purposes, except those of a scientific nature, it is desirable to state the economy of a steam engine in terms of the thermal units required per indicated horse-power per hour (or per minute), and that, if possible, the thermal units required per brake horse-power should also be given.

(3) That for scientific purposes the thermal units that would be required by a perfect steam engine, working under the same conditions as the actual engine, should also be stated.

The proposed method of statement is applicable to engines using superheated steam as well as to those using saturated steam, and the objection to the use of the number of pounds of feed-water, which contain more or less thermal units according to conditions, is obviated, while there is no more practical difficulty in obtaining the thermal units per indicated horse-power per hour than there is in arriving at the pounds of feed-water.

For scientific purposes the difference in the thermal units per indicated horse-power, required by the perfect steam engine and by the actual engine, shows the loss due to imperfections in the actual engine.

A further great advantage of the proposal is that the ambiguous term "efficiency" is not required.