PROTECTION FROM LIGHTNING. 



Danger proportionate to the Magnitude, not to the frequency of the Evil.— Ancient Methods of avert- 

 ing Lightning. — Persons in Bed not Secure, as some think. — Augustus's Sealskin Cloak as a Light- 

 ning Protector. — Influence of Color on the Electric Fluid. — Tiberius's Crown of Laurel as a Light- 

 ning Protector. — The Danger of taking Shelter beneath Trees. — Futility of taking Shelter in Glass 

 Cages. — Metal about the Person destroyed by Lightning. — Metal Appendages to be laid aside. — 

 Lightning Explosions occur at the Points where it leaves or enters a Metal. — Part of a Room 

 which is most Safe. — Lightning more likely to discbarge among a Crowd than on a single Individ- 

 ual. — Influence of the Vapor of Transpiration, &c. — Certain Individuals are comparative Non- 

 conductors. — Thunder- Clouds have been traversed with Impunity. — Thunder-Storms below the 

 Place of Observation. — Paratonnerres, or Lightning Conductors. — Lightning Conductors pro- 

 tective even when no Flash strikes them. — Sparks at the Interval where a Conductor is dis- 

 jointed. — Lightning Conductors drain off the Electricity of Clouds.— Sparks or luminous Aigrettes 

 on the Point of Conductors. — More frequent Occurrence at Sea. — Influence of Elevation of a Par- 

 atonnerre. — Experimental Illustration. — Electric Kites. — Captive Balloons as Paragreles and for 

 Meteorological Research. — Pointed and blunt Conductors. — Quantity of Lightning drawn down 

 by a Conductor. — Mr. Harris's Conductors for Ships. — Assumed Extent of the protecting Power 

 of a Paratonnerre. — Not based on experimental Grounds. — Cases against its general Application. — 

 Lightning does not alway strike the highest Points. — Lightning Conductors with many Points. — 

 A Lightning Conductor must have sufficient Capacity. — A Lightning Conductor must be in good 

 Connexion with the moist Sub-Soil. — Charcoal Beds to receive the Base of the Conductor. — Vici- 

 nal metallic Conductors. — Conductors of metallic Wire- Rope; Insulation not needed. — Conduct- 

 ors for Powder Magazines. — Efficacy of Lightning Conductors. — Lateral or divided Discharge 

 defined ; its Cause. — More readily obtained from Conductors than from Leyden Discharges. — 

 Line or Lines of least Resistance. — Absolute Necessity of connecting the Conductor with vici- 

 nal Bodies. — Artificial Means of producing the Electrical Odor. — Chemical Changes. — Fusion. — 

 Fulgurites. — Mechanical Effects. — Effects of conducting Bodies. 



VOIi. II.— 7 



