92 
TRANSACTIONS OF THE PLYMOUTH INSTITUTION. 
DESCRIPTION OF DIAGRAM. 
This Diagram has been reduced by photography from the original, exhibited 
at the lecture, in which all the rail sections, with one exception, were drawn 
to their full size ; by this means accuracy has been ensured. 
Morwellham sections, left-hand top corner. The section on the left 
represents the rail now on the ground, and shews the method adopted for 
fastening to the chair by means of an iron key. The right-hand section has 
no claims to absolute accuracy, and is merely diagrammatic, intended to give 
some idea of the probable form of the earliest rail used on the incline. 
Wadebridge. — The first section on the left is that of the earliest form of 
rail used on this line, weight 37 lbs. per yard. The section to the right is 
that of the last rail of 1864, weight 56 lbs. per yard. The section in the centre 
is a Vignoles steel rail, weight 68 lbs. per yard, now replaced by South 
Western Railway standard- way. 
1838. — This portion of the diagram has been taken from Weale's Public 
Works of Great Britain, published in 1838. The first section in the top row 
on the left hand is that of the rail then in use on the Manchester and Bolton 
Railway ; the next to the right was in use on the Croydon Railway ; the 
next two were both used on the Stanhope Railway ; and the next two on the 
Darlington. The rail in the centre between the two rows was that in use on 
the Great Western ; and in the lower row running from left to right the rail 
sections are those of the following railways : Whitby and Pickering, Green- 
wich, Clarence, Leeds and Selby, Manchester and Liverpool, Dublin and 
Kingstown, Newton and Warrington, London and Birmingham. 
1888. — Immediately opposite these, to the right, are figured some of the 
forms of rail now in use (1888), drawn to the same scale and in the following 
order : Left-hand top corner, Princetown Railway, 80 lbs. per yard ; Pemi- 
sylvania U.S. Railroad; Bodmin Railiaay, 75 lbs. per yard; and Bristol and 
Exeter, 74 lbs. per yard. Below these, the first section on the left is an 
intermediate Great Western, between that of 1838 and that of 1888, weighing 
40 lbs. per yard. The adjoining section represents the modern Great Western 
Railway rail, weighing 68 lbs. per yard. 
Plymouth and Dartmoor. — Commencing in the right-hand top corner of 
the diagram, the first detail given is a plan with elevation and section of the 
original cast-iron edge-rail, four feet long and six inches deep in the centre. 
This is the only section of rail on the diagram to which the Scale for Details 
in the right-hand top corner does not apply. Working downwards from left 
to right, the next sections in order are those of a rolled iron rail, weighing 
60 lbs. per yard ; ditto weighing 45 lbs. per yard ; ditto weighing 53 '25 lbs. 
per yard. A smaller one in the centre, between two sections of chairs, 
is also a rolled iron rail, weighing 38§ lbs. per yard. 
Of the two chairs, of which sections and half plans are given, that to the 
left weighed 10 lbs., and was used for edge-rails with lap-joints ; that to the 
right weighed 13 lbs., and was used for another pattern of edge-rail with 
butt-joints. 
In the centre of the diagram are two plans, the scale for which is in the 
left-hand corner. All that need be said with regard to the Heytor plan is 
that the hatched portion is meant to represent the raised half of the stone, 
and the plain portion the rebate, in which the wheels ran as indicated at A 
on the section. The plan of the Plymouth and Dartmoor Railway explains 
itself ; running otf to the right at the top of the diagram is shewn the com- 
mencement of a granite siding. 
