The part of a battleship where a shell hitting her would likely do the most damage is at her water-line and if a shell should hit there and explode it might tear out a big hole when she would quickly fill with water and sink. To prevent this from happening a very thick band of steel armor plate is riveted all the way round her at the water-line. All the machinery and equipment of the ship including her engines, boilers and machinery, the powder magazines and shell rooms, the passageways through which the ammunition is taken, the wireless room, in fact everything except her guns, is in the hold below this strong deck. Of course there must be some openings in this deck but these are protected by gratings of heavy steel, the bars of which set closely enough together to keep fragments of shells from going through should one hit and explode on deck. On our battleships the main battery is generally made up of four 10 inch, 12 inch or 13 inch breech loading guns and these are mounted in revolving turrets one of which is forward and one aft. The _Alabama_ had four 13 inch guns in the large turrets and twelve 6 inch guns on the broadsides. I’m telling you that if Huerta had been at Vera Cruz when we got there and taken a look into the muzzle of one of our 13 inch guns he’d have saluted the flag without any more of that mañana business. As it was he was safely out of range of our guns for Mexico City is over 200 miles from Vera Cruz. In the early days of wireless when every Tom, Dick and Harry was getting up a “new” wireless system the _Navy Department_ tried out all of them. It would not use the Marconi system because the government wanted to buy the apparatus outright while the policy of the _Marconi Company_ was to lease their apparatus. The favorite type of wireless apparatus used by the _Navy Department_ was known as the _Telefunken_, a German getup that was a combination of the Slaby-Arco and the Braun-Siemens and Halske systems. The transmitter of our station was one of this kind and consisted of an induction coil with a mercury turbine interruptor, an electric motor to run it and the usual key, loose coupled tuning coil and condensers. The receiver was of a later type and had both a _crystal detector_ and a _vacuum tube detector_, the latter being the invention of Dr. Fleming of England who has been Marconi’s technical adviser for many years. This detector is really a small incandescent lamp bulb with not only a filament but a metal plate sealed in it. The filament is kept at a white heat by a current from a storage battery. When the telephone receivers are connected to the hot filament and the cold plate electrodes, the high frequency currents that are set up in the aerial by the incoming electric waves are changed into direct currents and the varying strength of these act on the head-phones. This detector is very sensitive and needs no adjusting.