TRANSACTIONS OF SECTION G. 779" 



■was neither tlie most economical nor handy for management, from the fact that the 

 lamps required to be specially ordered and made of a slightly decreasing resistance 

 in proportion to their distance along the main leads from the generator, and that 

 ■ndthout a costly and deUcate current regulator there was considerable risk in spoiling 

 the remaining lamps upon turning out a number of them. He said the plan of 

 introducing an equivalent resistance to that of the lamp turned out was equiva- 

 lent to throwing away so much energy, or coal, because the resistance so introduced 

 absorbed power equal in fact to that of the lamp or lamps which it replaced. 

 Finally, he gave several plans for joining up the lamps which, in his opinion, were 

 more economical and better, and he stated that by using Siemens' dynamo-exciters 

 with their alternate current machines, the danger accruing from suddenly turning 

 out a number of lamps was avoided, as the electro-motive force remained prac- 

 tically constant (with low resistance leads and generator coil), and therefore the 

 current passing the remaining lamp or lamps was always the same. For example, 

 if 49 lamps out of 50 were suddenly switched out of circuit, the remaining lamp 

 would not be endangered, and would have the same current passing through it and 

 give the same light as before. He reviewed in detail the most approved mechanical 

 and electrical apparatus for installing electric lighting in coal mines, and 

 mentioned that he had found by experiment that good Swan lamps will give forth 

 light at the rate of 220 candle-power per horse-power absorbed by them. 



4. On a Screw Gauge for Electrical Apparatus. 

 By W. H. Preece, F.B.S. 



On the Value of Quadriform Gaslights for Lighthouses in comparison 

 with the Electric Light. By J. R. Wigham. 



TUESDAY, SEPTEMBER 6, 



The following Reports and Papers were read : — 

 1. Report of the Committee on Patent Legislation. — See Reports, p. 222, 



2. Beport of the Committee on the Steering of Screw Steamers. 



3. Beport of the Committee on Wind Pressiire. 



4. Beport of the Committee on Tidal Observations in the English Channel 

 and the North Sea. — See Reports, p. 160. 



5. On some applications of Electric Energy to Horticidtural and Agricul- 

 tural purposes. By Dr. C. Wm. Siemens, F.B.S. — See Reports, p. 474. 



6. i)n the Transmission of Poiver by Electricity. 

 By J. N". Shoolbred, C.E., F.G.S. 



