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JOURNAL OF THE PLYMOUTH INSTITUTION. 
length. Through this it is seen that a moderate charge passes 
in a brilliant spark from end to end. 
The effects of the discharge from the intensity, as compared 
with the quantity arrangement in battery connection, are very 
curious, and open up a wide field for investigation. 
'None of the quantity effects are lost, but, on the contrary, 
intensity appears to add to the electromotive force by overcom- 
ing the resistance in fine metal conductors, for it is seen that 
the deflagration of gold leaf and metallic wires is more brilliant 
and the oxidation more complete with the intensity than the 
quantity discharge. The results obtained from this apparatus are 
Buch as to warrant the conclusion that with a more extensive 
arrangement of jars, and machines of suitable power to charge 
them, and, lastly, a room of a size sufficient to keep the walls, 
roof, and floors beyond striking distance, electrical sparks of 20 
or 30 feet in length might be procured, since the high intensity is 
only developed at the moment when the jars are simultaneously 
brought into the consecutive or intensity position. The sparks 
at present obtained are so brilliant and crooked in their path, 
deviating sometimes more than a foot from the straight line, that 
they in fact constitute a miniature flash of lightning, for which 
reason I have been induced to apply to the instrument the term 
Fulgurator. 
PEEHISTOEIC AOTIQUITIES OF DARTMOOR 
ABSTBACT OF MR. SPENCE BATe's PAPER. 
(Read October 13th, 1870.) 
He treated first of the physical characteristics of Devonshire 
— The Derivation of the name of the County. Then on the 
physical condition of Dartmoor — Earliest records relating to it, 
1236 — Derivation of the term (Forest) — Its doubtful wooded 
state — Its sterile character — Its climate in Summer and in 
"Winter. "The mother of many rivers" — Antient Tin Works — 
Smelting-houses — The description of supposed Britain by the early 
geographer Hecataeus — Ancient roads over the Moor — Fitz's well — 
Hut dwellings — Their form, and style of elevation — Walled en- 
closures, commonly called Pounds — Sacred circles — as Fern worthy — 
