520 Notices of Memoirs—Ezeter’s Water Supply. 
trace of the original crust remains. If the theory is applied to the 
moon, where there is less gravitation, and there undoubtedly were 
once immense active volcanoes, it accounts well for some of the slower 
moving meteorites, which may have been travelling round the sun in 
orbits which intersected our own, since the time when the moon’s 
volcanoes were active. 
Their most probable origin is to be found in the primeval nebula, 
of which the comets are fragments. Comets travel in orbits round 
the sun, which are longer and narrower than the orbits of the planets. 
Passing too near a planet, a comet may become captured by its 
attraction, and have to revolve in a new orbit, which carries it around 
the sun, and then back to the place where the planet captured it. 
It thus becomes a short period comet. 
When comets first become visible to us they are tailless, but as 
they approach the sun the tail appears and grows, and is usually 
repelled by the sun. The heat of the sun drives vapours out of the 
head of the comet (which consists of a cluster of meteors); the 
electrons thrown out by the sun condense these vapours into particles 
so small that they can be repelled by the sun’s light against gravitation, 
thus forming the tail. The tenuous character of the-tail is clear from 
the fact that it does not obscure the stars from our vision. 
To sum up the history of these bodies, Mr. Fletcher went back to 
the nebula, from which all stars are formed. It condenses into 
a system like our Solar System, but some fragments or wisps are left 
out, which form the heads of comets and travel round the central sun 
in long orbits. They are caught by planets and reduced to smaller 
orbits. The emission of the tail gradually wears them out till they 
become tailless, and are reduced to streams of meteors. These get 
in time strewn round their orbits. Then the question arises, are 
meteorites and shooting stars the same? In general it would seem 
so, but in that case the meteorites which reach the earth in tangible 
form must be the very largest shooting stars, as the usual shower of 
them only produces the finest dust. 
IIJ.—Hisrorican Manuscripts Commission: THe Earty WATER 
SuppLy oF EXETER. 
ik the Report on the Records of the City of Exeter, just issued by 
the Historical Manuscripts Commission (characterized by the 
halfpenny Press as ‘‘ waste of paper’’), will be found the following 
interesting documents relating to the water supply of Exeter City. 
‘©1260. The Prior and Conyent of St.’ Nicholas grant leave to Martin 
Durling and his heirs to draw water ‘ab aqueducto que est in cemeterio nostro 
ce Occidentali parte ecclesia nostre per gardinum nostrum quod est in occi- 
dentali parte que ducit a magno vico usque ad Fratres Minores’.”’ 
“1299. Agreement on the part of the Mayor and Commonalty of Exeter by 
consent of Edmund, Earl of Cornwall, with Henry de Bolleg’, Archdeacon of 
Totnes, concerning the building of a tower next the said Archdeacon’s house— 
‘ per quam communis aqua civitatis ingreditur.’ ’’ 
‘©1346. Settlement of a dispute between the Prior of St. Nicholas on the 
one side and the Dean and Chapter of the Cathedral and the Mayor, etc., on 
the other, in regard to the making and repairing of the common water 
‘conduit’, the water of which rises “without the East Gate in St. Sidwell’s 
parish.”’ 
ee 
