330 REPORT — 1869. 



judicial influence. The imperfect or defective nature of the sewerage may, by 

 allowing- infiltration of sewage into the soil and its passage to the foundations 

 of houses, in some cases be the cause to which this result is referable._ But 

 one part of the sewerage system which most urgently demands attention at 

 the present time is the ventilation. Gases of a poisonous or deleterious nature 

 are freely given off from liquid sewage in its passage along the sewers, or 

 from deposits collecting in them and in the house-drains. These gases na- 

 turally ascend the sewers, and find egress, either into the streets of a town or 

 into the dwellings, by means of the house-draias and otherwise. The means 

 adoi^ted for getting rid of these gases, without injury to the sanitary state 

 of a town or of the houses in it, are rarely of such a kind as to be effective ; 

 and the returns already obtained in reference to this matter sufficiently show 

 that attention has not been directed to it in a degree commensurate with its 

 importance. 



On these grounds the Committee considers that it would be in the highest 

 degree desirable to institute an inquiry into the nature of the gaseous ema- 

 nations from sewers in various places, that being one of the points now most 

 important in connexion with the system of disposing of excretal refuse which 

 is rapidly being adopted throughout this country. In reference to the appH- 

 cation of liquid sewage to laud, it is also considered that, in addition to va- 

 rious other points relating to the application and purification of sewage-water 

 by ii-rigatiou, it would be very serviceable to make some inquiry into the 

 nature of the sewage discharged in various places, so as to ascertain the dif- 

 ferences that exist in Hquid sewage so far as its value as manure is con- 

 cerned, and at the same time to endeavour to obtain more deiiuite information 

 as to the cost of removing night-soil, and as to its agricultural value as esta- 

 blished by practice. 



Supplement to the Second Report of the Committee on the Condensation 

 and Analysis of Tables of Steamship Performance. 



The Committee have to report that the sum of £30 granted to them has 

 been wholly expended in the payment of Mr. Quant, their calculator, as 

 authorized hi the resolution by which they were appointed. The calculator's 

 time was employed partly in revising the printed Tables, which appeared in 

 the volume of Eeports for 1868, and partly in making an additional analyzed 

 Table. The last-mentioned Table in MS. was delivered to the Secretary 

 of the British Association early in the present year, and is annexed hereto. 

 The Committee beg leave to represent that it is desirable that they should be 

 reappointed, for the purpose of superintending the printing of that Table ; but 

 that no further grant of money will be required. They have again to express 

 their satisfaction with the manner in Avhich Mr. Quant performed his duties. 



Revised Ancdysis, according to the method of Mr. Scott Russell. 



In the Table of analyzation according to Mr. Scott EusscU's method, as 

 originally computed, the length of forcbody Avas assumed at -55 of the length 

 of the ship, which in practice is generally the place of the midship section. 

 This length of bow belongs to the displacement of the ship, but not to the 

 speed. Therefore in calculating the resistance there are introduced a coeffi- 

 cient of diminished resistance belonging to one bow and a speed belonging to 

 another bow, or, in other words, two ships have been used. 



