134 THE SCIENTIFIC PAPERS OF 



constructed in a hundred different ways to suit the requirements 

 or the fancy of their designer. He looked upon the construction 

 of a telegraph post as one of the most definite things which an 

 engineer could have put before him. Whether the pole was to 

 support straight wires, with only moderate lateral strains to bear, 

 or whether it was to be an angle post to resist the strains of wires 

 pulling in opposite directions, the problem always was to support 

 a strain at a certain height above the ground. This was the one 

 of the points which could be solved in a thoroughly mechanical 

 manner. He had found that the lower portion of the post, which 

 was exposed not only to the strain of the wire but to the moisture 

 of the ground, ought to be of a different material to wrought iron, 

 which corroded very readily, and, therefore, took cast iron, which 

 seemed to be the most suitable material. Then came the next 

 point. How is this base to be fixed in the ground ? The natural 

 suggestion was : make the whole tube uniform, and put the post 

 in and ram it all round. But what was got then ? A very smalt 

 post indeed as compared with a wooden post small in diameter, 

 necessarily so because limited in weight and constructed of a 

 material of greater density. It would, therefore, be necessary to 

 put the iron post deeper in the ground than the wooden post. 

 Major Webber claimed for the posts constructed on his principle 

 two advantages over those proposed and used by Mr. Siemens, 

 (1) less excavation, and (2) saving of material. He thought that 

 in both instances Major Webber was mistaken. Firstly, as regarded 

 excavation, Captain Mallock had already stated that if a hole could 

 be made 6 feet deep, it had to be made of such a size that a man 

 could get in. Now the base plate for supporting his (Mr. Siemens's) 

 post was less than 3 feet in diameter, 2 feet 8 inches, or there- 

 abouts, so that in reality no larger excavation would be required 

 for the pole with the base plate than for the pole without a base 

 plate, the only difference being that for the former the excavation 

 need only be 2 feet C inches, or 3 feet deep, while for the latter it 

 would have to be 6 feet deep. With regard to the weight of metal, 

 Major Webber had said that the weight of the base plate might be 

 saved by extending the length of the tube into the ground. The 

 depth he gave it was a very ordinary depth was 6 feet. Now 

 the extra length of the cast-iron tube the difference between 

 2 feet 8 inches and G feet, i.e., 3 feet 4 inches would weigh 



