Recently Patented Inventions

1897 Scientific American  
60 drivers. The engines have cylinders 7 inches in dia meter by 10 inches stroke, and by means of cut gearing run a countershaft. From this countershaft the front axle of the rear truck is driven by a heavy steel chain; the back axle of the front truck being driven by chains frolll the back trucks. The sprocket wheels are double flanged, so as to prevent the chain from running off. All the gearing is made of cast steel. Both the front and rear axles of the locomotive. a� will be seen from the
more » ... graving, are run by means of side connecting rods. The 40 horse power boiler, which is of a special locomotive type, is fed by a small duplex pump. The locomotive is also provided with a steam �iphon for drawing water into the tanks. It has been in use for some months on a rough wooden track, haul ing from 30,000 to 40,000 feet of logs per day. The total cost of building the wooden track is from $300 to $400 per mile. according to the class of country on which it runs. Where the ground is rather swampy, it requires several small bridges, but on ordinary level ground the cost does not exceed $300. This machine is so geared as to take ordinary loads at from four to six miles per hour, and if first-class track is furnished, the speed will be considerably �reater. The Curtis Manufacturing Company, of St. Louis, who are the builders, state that this engine, which is run by two men, is doing work which formerly required thirty yoke of oxen and five men. .1 ... Mosquitoes and Malaria. Recent researches show that it is very probable that malaria may be propagated by mosquitoes. Dr. Amigo Bignani brings forward some proofs in support of this theory. His article is translated into English and pub li�hed in the Lancet, from which we take the following: " If one admits the inoculation hypothesis, many facts which are difficult to explain by the theory of air con duction would find a simple and satisfactory explana tion, and it is easy to demonstrate this. First of all, the fact, which we have already discussed at length, that malaria is not carried by the winds, would be easily understood, knowing as we do how closely these diptera are bound to the soil on which they are hatched, and how adverse they are to allow themselves to be carried away, hiding, when the wind blows, in the ground, among the grass, or under the trees. Also when a sea breeze blows in the afternoon the mosqui toes of the Roman Campagna do not show themselves, and only when the wind has gone down at the setting J titutifit �tUtritJu. of the sun do they rise in clouds everywhere and attack animals and men. That the evening and night hours
doi:10.1038/scientificamerican01231897-60 fatcat:s2r2oxjvqbcbheoqbm4gns46c4