16 Decay of Gaspipes in certain Soils. 



Besides the difference in general features above considered, 

 there are others, notably the presence in the Melbourne 

 sketch of a pair of bright wings at the N. extremity of 

 the lemniscate, which are not indicated in the Cape drawing ; 

 this, however, and other differences of detail are in the direc- 

 tion to be accounted for by difference of aperture used, no 

 certain conclusion can therefore be yet drawn therefrom. 



Art. IV. — Decay of Gaspipes in certain Soils. 

 By G. FooRD, Esq. 



[Eead 14th February, 1870.] 

 In September, 1867, it became the duty of the writer of 

 this note to inquire into the cause of the decay of a gas- 

 main, the property of the city of Melbourne Gas Company. 

 The scope of the question submitted did not, at that date, 

 extend beyond its purely commercial sense ; but as there 

 appears good reason for regarding the particular case as 

 typical, and significant in reference to the broad subject 

 of the "life" of gas and water mains, and because the 

 subject has a scientific interest quite apart fi?om its purely 

 economic sense, I venture to lay before your Society such 

 results as happen to be at this date at my command. In 

 doing this, I wish to state that the particulars which 

 I have to communicate are slight and imperfect ; that no 

 pretentions to a close investigation are set up ; and that I 

 should not have risked the presentation, for registration, of 

 so imperfect an account of a fact of confessedly great intrinsic 

 interest, if I had not been encouraged by your President with 

 the assurance that your Society is always ready and anxious 

 to receive and record matters of fact and scientific interest, 

 even though the observations may happen to be of a dis- 

 jointed and casual character. I confess a personal concurrence 

 in those views, for in our new continent, over the expanse of 

 which promising objects, inviting observation, are so abun- 

 dant, but in which the number of precise observers are, 

 relatively to the field of inquiry, so few, doubtless for some 

 time to come, observation, as distinguished from methodical 

 research and experiment, must take the lead ; and the record 

 of casual observations, even when unsupported by any 

 extent of continuous inquiry or systematic experiment, must 

 prove ultimately valuable. It is this conviction, coupled 

 with the personal assurance of your President, which tempts 



