436 Chronicles of Science. [July, 



Holland, E.N. ; and on " Strains in Propeller Shafts," by Mr. AV. J. 

 Macquorn Rankine, C.E., LL.D., F.E.S. 



Association of Engineers, Glasgow. — At a meeting of this 

 Association in April last, the President, Mr. John Page, C.E., read 

 a j)aper on " Pipes and the Jointing of Gas and Water Mains." 

 In alluding to the enormous waste of gas through leakage, Mr. 

 Page reviewed the different modes of jointing at present in use, and 

 dwelling on the difficulty in maldng and maintaining good joints 

 imder any circumstances, particularly in the curved pipes, he 

 exhibited drawings of a very simple system, and clearly showed 

 that a joint on a curved pipe made in that manner could not move ; 

 a joint tested under the most unfavourable circumstances having 

 stood a pressure of 600 lbs. to the square inch. 



A paper by Mr. Eobert Burn, on " The Machinery used for 

 Cleaning and Packing East India Cotton, and on the Apphcation 

 of the Seeds for Feeding Cattle," also deserves a notice, as dealing 

 with a subject of first importance to India, and to the cotton 

 manufacturers of this country. 



Institution of Mechanical Engineers. — At a general meeting 

 of the Institution of Mechanical Engineers, held at Birmingham on 

 2!ith April last, a paper was read by Mr. James S. E. iSwindell, 

 being a " Description of Guibal's Ventilating Fan employed at the 

 Homer Hill Colliery, Cradley." This fan has eight vanes, and 

 revolves on a horizontal shaft within a cylindiical casing of brick- 

 work. The fan is 16^ feet in diameter, and 4| feet wide; its 

 usual working speed is twenty-six revolutions per minute, dis- 

 charging 13,500 cubic feet of air per minute ; but it can be got up 

 in one minute's time to ninety-six revolutions, discharging 51,700 

 cubit feet per minute. This is the first mechanical ventilation that 

 has been applied in the working of the South Stafi"ordshire thick 

 or ten-yard coal. It has now been running about nine months 

 without a single stoppage for repau^s. The total cost of the fan, 

 with engine and connections, is only about one-third of that of an 

 ordinary ventilating fmnace for producing the same amount of 

 ventilation. 



Another paper, by M. E. Gellerat, of Paris, was a " Description 

 of the Steam Eoad Poller used in Paris." This roller consists of a 

 locomotive engine carried entii'cly upon two large cast-iron rollers 

 of equal size, which are both driven by the engine, the course of 

 the machine being controlled by a s])ecial arrangement for changing 

 the direction of the roller axles. The results of numerous data 

 show that the cost of horse rolling in Paris is about 14(7. per ton 

 per mile, whereas for steam road rolling the actual payment is only 

 lialf that amount, or Id. per ton per mile, including the contractor's 

 profit. 



