Unpublished paper, 'On the valuation of the mechanical effect of gradients on a line of rail road' by Peter Barlow Barlow shares calculations for the mechanical effect of gradients on a line of rail road. Includes one table in the text showing the lengths of horizontal lines equivalent to the gradients on a proposed line of railway. The table headings are distance, gradient, rise or fall from London, equivalent horizontal line from London, equivalent horizontal line to London, and data employed in the calculation. Marked on back as 'archives'. Subject: Engineering / Mechanics Received 10 May 1836. Read 19 May 1836. 1836