28 ANNUAL OF SCIENTIFIC DISCOVERY. 



NEW MODE OF WARMING RAILROAD CARS. 



Experiments with a new system of heating railroad cars have been 

 instituted by M. Delcambre, in various parts of France, and have 

 been recently repeated on the Paris and Montargis section of the 

 Lyons line. By this plan, the steam which escapes from the locomo- 

 tive is carried by a caoutchouc pipe to the first carriage, and there 

 made to pass through conduits of copper, placed in the roof and the 

 floor, to the end of the vehicle, where it is received into another flexi- 

 ble pipe, and carried on to the next carriage, and so on from one 

 vehicle to another to the end of the train, where it escapes. The 

 fixing and removing of the caoutchouc pipes is accomplished with 

 the greatest facility, and the passage of the steam through the con- 

 duits presents no inconvenience to the passengers. By means of 

 the new plan a temperature of 59 Fahrenheit was obtained on an 

 excessively cold day, and at a merely nominal expense. 



LOCOMOTIVES ON COMMON ROADS. 



In anticipation of the adoption and use of locomotives on common 

 roads, to the perfection of which considerable attention has been of 

 late paid in England, a bill has been introduced into Parliament for 

 their regulation. It exacts that the weight on each pair of wheels 

 is not to exceed one ton and a half. The use of locomotives de- 

 structive to highways or dangerous to the public is to be prohibited 

 by the Secretary of State, so as to prevent the excessive woar and 

 tear. The weight of locomotives over county, parish, or suspension 

 bridges is not to exceed fifteen tons, and any damage is to be made 

 good. The locomotives are to consume their own smoke. Two 

 persons are to drive and conduct every locomotive, and red lights 

 are to be fixed conspicuously in front of locomotives and wagons one 

 hour after sunset till one hour before sunrise. The speed of loco- 

 motives on highways is not to exceed ten miles an hour, and through 

 towns, cities, or villages, five. No locomotive is to be used within 

 the city of London more than seven feet in width and with wheels 

 six inches wide. 



MILITARY ARCHITECTURE OF THE MIDDLE AGES. 



The above is the title of a work recently published in France, by 

 M. Viollet-le-Duc, and translated into English by Mr. MacDermott. 

 We derive from its pages the following items of information. 



There are two great eras in military architecture : the first being 

 the result of the Crusades, when the passive system of defence was 

 superseded by an activity equal to that required for an attack ; and 

 the second being that marked by the introduction of gunpowder. 

 The commencement of the latter era was the starting-point from 

 which the subject has gradually been divested of everything like 

 picturesque effect, till it has resolved itself, in the aspect of its fab- 

 rics, into the terrible uniformity and ugliness recognized by the term 

 barrack style. In so far as a revival of pictorial results might be 

 beneficial, the essay, with its telling illustrations, may be of service ; 



