PAGE I. ENGINEERING AND MECHANICS.--The New Railway up Mount Vesuvius. 6 illustrations. Plan of road.--General view of mountain and railway.--Side view and end view of passenger car.--Mount Vesuvius Railway.--Map showing railway, mountain, crater, and surrounding country.--The carriage road and railway 3735 The St. Gothard Tunnel--Notes on the junction of the two galleries. By Dr. CALLADON 3736 The St. Gothard Tunnel.--Conditions and causes of air currents in the tunnel 3736 Protection of Ships from Loss by Fire and from Loss by Sinking. Recent improvements in the construction of ships and steamers 3738 Regenerative Stoves.--A Sketch of their History and Notes on their Use. By JOHN N. HARTMAN. An important paper read at the Pittsburg meeting of the American Institute of Mining Engineers. 1 figure 3738 Cowper's Hot Blast Stoves. 2 full page illustrations of hot blast stoves for a pair of furnaces.--Plan and cross section of stove.--Plan and cross section of furnace.--Plan and cross section of gas downcomer.--Sectional elevation of stove and downcomer 3739 Wilson's Lock-up Safety Valve. An important improvement. 10 figures. 3742 Working Low Grade Ores 3742 The Largest Concrete Tank in England 3742 II. ELECTRICITY, ETC.--Siemens' Improvements in Electric Railways. 4 figures. Siemens' combined steam and electric railway.--Siemens' electric mail railway 3743 Difference in the Actions of Positive and Negative Electricity 3743 Forces Exciting Electricity 3743 The New Electrical Middlings Purifier. By THOS. B. OSBORNE. 5 figures 3744 Physical Society, London. Photo--electricity.--Electrometer key.--Air in water.--Steam thermometer 3745 Atmospheric polarization. Influence of terrestrial magnetism 3745