ACTION OF WATER ON IRON. 



309 



iron (our standard), and pressed together by known weights. 

 The loss of weight sustained by the wheels would then indicate 

 their respective ratios of abrasion, the loose axles being, pre- 

 viously to weighing, taken out so as to eliminate their wear from 

 that of the face of the wheel. 



This method and the probability of its giving correct results 

 have been suggested to me by the uniformity with which the 

 wheels of railway carriages wear when tyred with the same iron. 

 Railway experience also shows that the resistance to abrasion 

 in rails of wrought iron is to that of cast iron as 15:4. 

 (Wood on Railways. ) 



139. In conclusion, I have to regret that my friend Professor 

 Davy's public avocations have hitherto prevented his devoting 

 more of his attention and great experimental skill to this sub- 

 ject, which, while it has been entrusted to us conjointly, would, 

 I am certain, in his hands have found an abler reporter. 



Our thanks also are due to the several public bodies and pri- 

 vate individuals to whose assistance we are indebted in making 

 our experiments. — To the Board of Public Works and the Bal- 

 last Corporation of the Port of Dublin we are under obligation, 

 not only for personal assistance, but for freely placing their 

 stores in Kingstown Harbour and the Port of Dublin at our 

 disposal. 



Note. 



Since the foregoing report was sent to press it has been con- 

 sidered unnecessary to print the tables of experiments on the 

 great scale referred to therein at length in this volume, in as 

 much as at present they necessarily consist more of data than 

 of results, the latter demanding the lapse of time for their col- 

 lection. It has been therefore determined at present merely 

 to give a synoptic view of those tables of experiments in 

 progress. 



These experimental tables at present contain the following 

 data respecting the specimens of iron submitted to trial, viz. 



The whole series of experiments in progress on the great 

 scale is contained in five separate boxes, each containing seve- 

 voL.vn. 1838. x 



