22 JOUENAL OF THE PLYMOUTH INSTITUTION. 



it was stated, was found as brine or salt springs in the silurian rocks 

 of Cumberland and Radnorshire, and in the carboniferous and triassic 

 rocks of I^orthumberland, Durham, Lancashire, Cheshire, Leicester- 

 shire, and Worcestershire ; as rock or fossil salt in Cheshire, "Wor- 

 cestershire, and Durham ; and was procured by evaporation of sea 

 water at Salines, as at Lymington. The author then gave an his- 

 torical sketch of the rise and progress of the salt trade, commencing 

 at the time of the Confessor, and particularly noticing the discovery 

 of the rock salt at jN"orthwich in 1670, and the subsequent exten- 

 sion of the trade. The geological position in Cheshire, and some of 

 the physical results arising from the extensive workings, were then 

 mentioned, and the paper concluded with an account of the manner 

 in which the salt was manufactured at the salt works in Cheshire, 

 and at the Salines. 



A Paper will be read on the 25th November on 



THE CENTENARY OF THE STEAM ENGINE. 



By Mr. R. Oxland, r.c.s. 

 PROGRAMME. 



Early History of Steam Power. — Different methods of using 

 steam previous to the production of the Steam Engine by James 

 Watt in 1769. — Description of Watt's Low Pressure, High Pres- 

 sure, and Locomotive Engines. — The principal Improvements 

 introduced since the time of Watt. — The purposes for which the 

 Steam Engine has been employed. — Effects already produced 

 thereby and probabilities of the future. 



THE BASES OF HISTORY. THE MATERIALS. 



ABSTRACT OF MR. ROOKER'S LECTURE. 



This lecture, on the Materials available for the construction of 

 History, was supplementary to previous lectures on the Bases of 

 History, in which the lecturer, having considered early legendary 

 traditions, — the myths of history, — and its doubtful or insoluble 

 facts, — the enigmas of history, — had endeavoured to show that 

 history, as being the relation of political events in their order of 

 succession, is distinct from the past conditions of social life — from 



