Second Report of the Committee appointed to consider and report on the various Plans proposed for Legislating on the subject of SteamBoiler Explosions, with a view to their Prevention,-the Committee consisting of Sir WILLIAM FAIRBAIRN, Bart., C.E., LL.D., F.R.S., JOHN PENN, C.E., F.R.S., FREDERICK J. BRAMWELL, C.E., HUGH MASON, SAMUEL RIGBY, THOMAS SCHOFIELD, CHARLES F. BEYER, C.E., THOMAS WEBSTER, Q.C., and LAVINGTON E. FLETCHER, C.E. SINCE the first Report on the subject of "Steam-Boiler Legislation" was presented to the Mecting of the British Association, held last year at Liverpool, the Parliamentary Committee "appointed to inquire into the cause of SteamBoiler Explosions and the best means of preventing them" have presented their Report.

The consideration of the result of the Parliamentary Committee's inquiry clearly becomes one of the most important duties in reporting to the British Association on "the various plans proposed for legislating on Steam-Boiler Explosions, with a view to their Prevention." Unfortunately, however, the Parliamentary Report has been so recently published that there has not been time for its due consideration, or for the Committee appointed to treat on this subject to meet and confer thereon. Under these circumstances it has been thought best not to attempt to enter upon the subject on the present occasion, but to postpone doing so until next year, after having an opportunity of watching the development of the measure, and its working when carried into actual practice; and therefore, in order that they might be in a position to report thereon to the next Meeting of the British Association, the Committee would beg to suggest their reappointment.

Report of the Committee on the " Treatment and Utilization of Sewage." Consisting of RICHARD B. GRANTHAM, C.E., F.G.S. (Chairman), Professor D. T. ANSTED, F.R.S., Professor W. H. CORFIELD, M.A., M.B., J. BAILEY DENTON, C.E., F.G.S., Dr. W. H. GILBERT, F.R.S., JOHN THORNHILL HARRISON, C.E., THOMAS HAWKSLEY, C.E., F.G.S., W. HOPE, V.C., Lieut.-Col. LEACH, R.E., Dr. W. ODLING, F.R.S., Dr. A. VOELCKER, F.R.S., Professor A. W. WILLIAMSON, F.R.S., F.C.S., and Sir JOHN LUBBOCK, Bart., M.P., F.R.S. (Treasurer). THE Committee, upon its reappointment at Liverpool last September (1870), proceeded at once to consider the subjects which seemed to demand immediate attention in furtherance of the investigation which had been again entrusted to it.

The first steps taken were to endeavour to procure information from the towns where works have been constructed for the application of sewage to land by irrigation, and from the places where the dry earth or Moule's system is in operation.

In order to commence the inquiry, a list of towns was prepared, to each of which a printed form of queries was sent; but only eight places have answered the circular on irrigation, and only one that relating to the dry-earth process. The answers from the towns have been tabulated, and the Table will be found at the end of this Report (Appendix A).

During the construction of the present tanks at Breton's Farm in the winter, very accurate observations could not at all times be made; but nevertheless, during the extreme frost, samples were taken of the sewage and of the effluent water. The temperature of both, and also the temperature of the

atmosphere, was observed. Similar observations were made at Croydon and Norwood (see Section I.).

The observations as to the quantity and quality of the sewage and effluent water have been continued at Breton's Farm, with slight interruptions, as stated above, from the Meeting of the British Association at Liverpool down to the present time. The results of the gaugings are recorded in the Tables which will be found in Section II. of this Report.

The Committee has visited several sewage-farms, and examined the various methods that are pursued at them with a view to determining the practical conditions upon which the success of sewage-farming depends. They have had samples of sewage and of effluent water collected, and have had analyses made of them, which latter, with the remarks of the Committee, will be found in Section III.

The phosphate process of Messrs. Forbes and Price has been also examined by a Member of the Committee, and a description of the process, with an analysis of the effluent water from this process, is given in Section IV.

Analyses of the soil which has passed once and twice through earth-closets have been furnished by another Member; and the manner in which this process is carried out at Lancaster, with the results attained there, is described in Section V.

An ox which had been fed for the previous 22 months entirely on sewagegrown produce was slaughtered on July 15th at Breton's Farm, and the carcass examined by Dr. Cobbold and Professors Marshall and Corfield, in the presence of several Members of the Committee, with a view to ascertain the presence or absence of Entozoa in any stage of their existence. The results of this examination, and Dr. Cobbold's report, will be found appended (Appendix B).

The attention of the Committee has been drawn to certain anomalies in the figures given in the list of rainfalls in the "Tabulation compiled from returns furnished by 200 towns selected for classification," at the end of last year's Report.

On referring to the original returns, it has been found that the figures given in the Table are correctly taken from them.

SECTION I.-A Comparison of Results obtained in the purification of Sewage at three Irrigation Farms during the severe frost of last winter.

1. Breton's Farm, near Romford.

The following analyses show the composition of average samples of sewage and effluent water collected on the farm on January 2nd; cach sample was made by collecting five portions at different times, and mixing them in proportion to the flow at the time.

The sewage, after passing through the tank and pump, contains more solid matters in solution but much less in suspension than the sewage as it comes from the town; the agitation causes some of the suspended matter to pass into solution; and it will be noticed that the amount of albuminoid ammonia in solution is nearly doubled, showing that a considerable amount of nitrogenous organic matter formerly in a state of suspension has been dissolved.

This sewage is very much stronger than the average summer sewage, which only contains from 2.5 to 4 parts of actual ammonia in 100,000; and so one would hardly expect it to be so satisfactorily purified (especially considering the extreme frost and the want of growth) as the sewage was during the summer.

Nevertheless the purification was very satisfactory indeed; for the effluent water only contained 0.143 of actual ammonia, instead of 5.628, while the albuminoid ammonia was reduced from 0.524 to 0.059.

From this we see that very little nitrogen passes away in the form of ammonia or of organic nitrogen, even in winter, when vegetation has least to do with the purification.

Some of it passes away, however, in the form of nitrates and nitrites; but the amount which is thus lost is very little greater in the winter than in the summer, being 1.208 part in winter and about 1.106 part in summer in 100,000 parts.

Thus it appears that, with an underdrained soil, the sewage being obliged to pass through several feet of soil before it escapes, (1) oxidation goes on in winter as well as in summer, and almost all nitrogen lost is lost in an oxidized and inoffensive form, and (2) this loss is very slightly greater in winter with a very strong sewage than in summer with a weaker one; so that sewaging in the winter would appear to entail no extra loss of manure.

2. Beddington Farm, Croydon.

Three samples of Croydon sewage, taken from Beddington Fields, 3rd January, 1871.

The analyses show that the sewage applied to this farm contained on January 3rd, 1871, just about the same quantity of ammonia as that applied to Breton's Farm on the day before.

The effluent water contained 0.744 part of ammonia, or between five and six times as much as that at Breton's Farm; the albuminoid ammonia was less in actual amount in the effluent water; but the reduction was from 0.188 to 0.045, or to one fourth of the original amount; while in the last case it was from 0.524 to 0.059, or to between one eighth and one ninth of the original amount contained in the sewage as pumped on to the land. The nitrates and nitrites in the cffluent water were in insignificant amount, thus

showing that the nitrogen that is lost on this farm is lost for the most part in the form in which it came on to the land, and that mere surface-action (which is relied upon here) is not sufficient to cause the oxidization of the ammonia and organic matters contained in the sewage. At the same time

the amount of purification effected was certainly very considerable.

3. Norwood Farm.

Samples of sewage and effluent water collected from Norwood Fields on January 5th, 1871.

The sewage employed on this farm was very strong, containing as much as 7.42 parts of ammonia in the 100,000.

It will be seen that more than two parts of actual ammonia escaped as such in the effluent water, while nearly one fourth of the albuminoid ammonia also escaped unaltered. At the same time a considerable amount of nitrogen was lost as nitrates and nitrites, showing that a certain amount of oxidizing action was going on.

Thus there was a considerable loss of nitrogen, both in its original forms and also as nitrates and nitrites.

It must be remembered that this sewage was very strong, and that in this, as in the other two cases, the samples were taken under the most disadvantageous conditions during a very severe frost, when growth was at its minimum. The purification is in every case very considerable; but these comparativo results speak volumes in favour of underdraining sewage-farms, and of so obliging all the sewage to pass through the soil.

Some interesting results were observed as regards the temperature of the sewage and effluent water.

At Breton's Farm in the winter the temperature of the sewage was 46° F., that of the effluent water 40° F. =4°.4 C., a reduction of 5° or 6° only; while at Beddington Farm the temperature of the sewage was 42° F., and that of the effluent water 34° F.=1°.1 C., a reduction of 8°.

Thus with percolation through the soil the reduction is during the winter much less than with surface-flow.

On the other hand, we have observed that sewage is always cooled (sco Table, Section II.) during the hottest weeks in summer by percolation through the soil, and almost always heated (sometimes considerably so) by a surface-flow during the summer.

These results are favourable to percolation through the soil as opposed to merc surface-flow, both in summer and winter.

Percolation causes a considerable cooling in the summer, while in winter it does not cool the effluent water so much as surface-flow docs.