These stupendous results have been attained gradually; if we go back to 1848, we find that on the London and Birmingham Railway the number of trains in and out of Euston was forty-four per day.  The average weight of the engines was 18 tons, and the gross loads were, for passenger trains 76 tons, and for goods 160.  Now, the weight of an express engine and tender is about 65 tons, and gross loads of 250 to 300 tons for an express, and 500 tons for a coal train are not uncommon, while not only have the trains materially increased in weight, owing to the carriage of third-class passengers by all (except a few special) trains, and also to the lowering of fares and consequent more frequent traveling, but the speed, and therefore the duty of the engines, is greatly enhanced.  A “Bradshaw’s Guide” of thirty-five years ago is now a rare book, but it is very interesting to glance over its pages, and in doing so it will be found that the fastest speed in all cases but one falls far short of that which obtains at present.  The following table will show what the alteration has been: 

_______________________________________________________

__________
|   1849.   |   1884.   |
|Speed miles|Speed miles|
| per hour. | per hour. |
-----------------------------------------+-----------+------

-----+
Great Western--London to Didcot.         |    56     |    --     |
"           "   to Swindon.        |    --     |    53     |
North-Western--Euston to Wolverton.      |    37     |    --     |
"        Northampton to Willesden. |    --     |    511/2    |
South-Western--Waterloo to Farnborough.  |    39     |    --     |
"        Yeovil to Exeter.         |    --     |    46     |
Brighton--London Bridge to Reigate.      |    36     |    --     |
"     Victoria to Eastbourne.        |    --     |    45     |
Midland--Derby to Masborough.            |    43     |    --     |
"     London to Kettering.            |    --     |    47     |
North-Eastern--York to Darlington.       |    38     |    --     |
"              "                   |    --     |    50     |
Great Eastern--London to Broxbourne.     |    29     |    --     |
"        Lincoln to Spalding.      |    --     |    49     |
Great Northern--King’s Cross to Grantham.|    --     |    51     |
Cheshire Lines--Manchester to Liverpool. |    --     |    51     |
-----------------------------------------+-----------+------

-----+

With this problem then before them, increased weight, increased speed, and increased duty, the locomotive superintendents of our various railways have designed numerous types of engines, of which the author proposes to give a brief account, confining himself entirely to English practice, as foreign practice in addition would open too wide a field for a single paper.