48 EEPORT 1881. 



been increased a Imnclredfold, wliile at the same time raucli higLer pre- 

 cision has been obtained. Sir Joseph Whitworth has done more than any- 

 one else to perfect the machinery of this coantry by the continued efforts 

 he has made, during nearly half-a-century, to introduce accuracy into the 

 standards of measurement in use in workshops. He tells us that Avhen he 

 first established his works, no two articles could be made accurately alike 

 or with interchangeable parts. He devised a measuring apparatus, by 

 which his workmen in making standard gauges are accustomed to take 

 measurements to the tto^oo o^ ^^ inch. 



In its more immediate relation to the objects of this Association, the 

 increased importance of iron and steel has led to numerous scientific 

 investigations into its mechancial properties and into the laws which 

 govern its strength ; into the proper distribution of the material in con- 

 struction ; and into the conditions which govern the friction and adhesion 

 of surfaces. The names of Eaton Hodgkinson, Fairbairn, Barlow, 

 Rennie, Scott Russell, Willis, Pleeming Jenkin, and Galton are promi- 

 nently associated with these inquiries. 



The introduction of iron has, moreover, had a vast influence on the 

 works of both the civil and military engineer. Before 1830, Telford had 

 constructed an iron suspension turnpike-road bridge of 560 feet over the 

 Menai Straits ; but this bridge was not adapted to the heavy weights of 

 locomotive engines. At the present time, with steel at his command, Mr. 

 Fowler is eno-aged in carrying out the design for a railway bridge over 

 the Forth, of two spans of 1,700 feet each ; that is to say, of nearly one 

 third of a mile in length. In artillery, bronze has given place to wrought 

 iron and steel ; the 68-pound shot, which was the heaviest projectile fifty 

 years ago, with its range of about 1,200 yards, is being replaced by a shot 

 of neai'ly a quartei--ton weight, with a range of nearly five miles ; and 

 the armour-plates of ships are daily obtaining new developments. 



But it is in raih'oads, steamers, and the electric telegraph that the 

 proo-ress of mechanical science has most strikingly contributed to the 

 welfare of man. 



As reo^ards railways, the Stockton and Dai'lington Railway was 

 opened in 1825, but the Liverpool and Manchester Railway, perhaps the 

 first truly passenger line, dates from 1830, while the present mileage of 

 railways is over 200,000 miles, costing nearly 4,000,000,000?. sterling. 

 It was not until 1838 that the Sirins and Great Western first steamed 

 across the Atlantic. The steamer, in fact, is an excellent epitome of the 

 progress of the half-century ; the paddle has been superseded by the 

 screw ; the compound has replaced the simple engine ; wood has given place 

 to iron, and iron in its turn to steel. The saving in dead weight, by this 

 improvement alone, is from 10 to 16 per cent. The speed has been in- 

 •creased from 9 knots to 15, or even more. Lastly, the steam-pressure has 

 been increased from less than 5 lbs. to 70 lbs. per square inch, while the 

 consumption of coal has been brought down from 5 or 6 lbs. per horse-power 

 to less than 2. It is a remarkable fact that not only is our British 



