Two steamers of a partially warlike character have just been built in our country for a Russian company, and are designed for trading between the Amoor river in Russian Asia, China and California. One named the Manjoor was built at Boston ; the other, named the Japanese, at New York. The latter is 1,400 tuns burden, the former 1,000 tuns. Their engines are strong, plain and compact, and designed for effective service, not show. They are both propellers, and have made their trial trips, running at the rate of from eight to ten knots an hour easily. Their model is good, and under sail alone they have the speed of clipper ships. Their draft of water is comparatively light,' as there are many shoals in the Amoor river. A great quantity of machinery, such as saw mills, are to be taken out in these vessels f or the Russian settlements, as it is believed that a considerable trade in lumber can be carried on between those regions and California. The Russians by this movement have exhibited a great amount of enterprise and sagacity. We have no doubt but their trade on the Pacific coast will soon become very lucrative, if well conducted; and the good sense which induced them to come among us to get these steamers built, affords very good grounds for their future success.