He concluded by saying:  The employment of paraffin oil for gas making has advantages in its favor, in the readiness of charging the retorts, as the oil can be run in continuously for days at a time, and may be discontinued and commenced again without opening, clearing out residual products, recharging and reclosing the retorts.  There is necessarily, therefore, less labor and cost in working, and as the gas is cleaner or freer from impurities, purifying plant and material will be correspondingly less.  Oil gas is now employed for lighthouse service in the illumination of the lanterns on Ailsa Craig and as motive power in the gas engines connected with the fog horns at Langness and Ailsa Craig lighthouse stations.  It is also used largely in the lighting of railway carriages.  Various populous places are now introducing oil gas for house service, and he felt sure that the system is one which ought to commend itself for its future development to the careful consideration and practical skill of the members of the Gas Institute.

* * * * *

THE MANUFACTURE OF SALT NEAR MIDDLESBROUGH.[1]

  [Footnote 1:  Abstract of paper read before the Institution of
               Civil Engineers, May 17, 1887.]

By Sir LOWTHIAN BELL, Bart., F.R.S.

The geology of the Middlesbrough salt region was first referred to, and it was stated that the development of the salt industry in that district was the result of accident.  In 1859, Messrs. Bolckow & Vaughan sank a deep well at Middlesbrough, in the hope of obtaining water for steam and other purposes in connection with their iron works in that town, although they had previously been informed of the probably unsuitable character of the water if found.  The bore hole was put down to a depth of 1,200 feet, when a bed of salt rock was struck, which proved to have a thickness of about 100 feet.  At that time one-eighth of the total salt production of Cheshire was being brought to the Tyne for the chemical works on that river, hence the discovery of salt instead of water was regarded by some as the reverse of a disappointment.  The mode of reaching the salt rock by an ordinary shaft, however, failed, from the influx of water being too great, and nothing more was heard of Middlesbrough salt until a dozen years later, when Messrs. Bell Brothers, of Port Clarence, decided to try the practicability of raising the salt by a method detailed in the paper.  A site was selected 1,314 yards distant from the well of Messrs. Bolckow & Vaughan, and the Diamond Rock Boring Company was intrusted with the work of putting down a hole in order to ascertain whether the bed of salt extended under their land.  This occupied nearly two years, when the salt, 65 feet in thickness, was reached at a depth of 1,127 feet.  Other reasons induced the owners of the Clarence iron works to continue the bore hole for 150 feet below the bed of salt; a depth of 1,342 feet from the surface was then reached.  During the process of boring, considerable quantities of inflammable gas were met with, which, on the application of flame, took fire at the surface of the water in the bore hole.  The origin of this gas, in connection with the coal measures underlying the magnesian limestone, will probably hereafter be investigated.