The climate of the West Indies is so moist that metal rusts in an amazingly short space of time, and it is difficult to keep anything bright and polished. It is supposed by those who understand the gun that, having been constantly exposed to the moist air, it has rusted, and that the important clasp has become so rusty that it can no longer be pushed fully home, and so the gun is not secure. In their opinion the failure of the dynamite-gun has not been proved; it may be necessary to make some alterations to fit it for service in swampy countries, but that as a weapon it is still a success. * * * * * Terrible floods are reported from the Mississippi Valley. A section of the country equal in size to the whole State of Missouri is now under water, and steamboats are hurrying over what were once farm lands, rescuing the unfortunate families who have been caught by the floods. The Mississippi, the largest river on our continent, flows through what is known as the Gulf Coast Plain. The Gulf Coast Plain is formed by the valley lying between the great mountain ranges which make the framework of our country. The Mississippi with its tributaries drains the whole of the enormous tract of land lying between these three main mountain ranges. This great river forms the highway for the interior of our country, and winds through the plain for about a thousand miles. Every year when the heavy spring rains fall, and the snows melt in the north, the river overflows its bed, and floods the lowlands around it. To keep the river within its bounds, mounds of earth, called levees, have been built for hundreds of miles along the banks. The Mississippi floods are only dangerous when the thaws are very sudden, or the rains so heavy that the river swells in size to such an extent that the levees are broken down, and the water, bursting its bounds, rushes with an angry flood over the surrounding country, destroying everything in its path. As a usual thing the spring floods are beneficial to the country, for the Mississippi is a very muddy river, and when it overflows it spreads this mud over the country, in much the same fashion that the Nile does, and with the same result of fertilizing and enriching the soil. All swift waters wash away some portion of their bed in their flow, and carry it along with them in their journey to the sea. The Mississippi in its thousand-mile course carries a vast amount of this stolen earth, so much indeed that every year it deposits in the Gulf of Mexico an amount of mud which would make a pile one mile square and 268 feet high. [Illustration] This enormous yearly deposit is literally filling up the Gulf, and in the ages to come dry land and a new country will be found where the waters of the Gulf now lie.