(2052) 
there being fo vaft a deal of room , that 40000 People may 
ihelter therafelves in it. And he that would attempt to feek 
them out in this vaft Wildernefs of Walks and Pillars5withouf 
an expert Guide, would not only be in hazard of loofing his 
way, but of being knock't in the head at the Corner of every 
Pillar, where people lurking in the dark with their Carabins 
and Fowling pieces, would have fair opportunity to jttioot 
them by the light of their own Torches. 
In this vaft Gr<?//(? *tis remarkable, that there is but little 
Rubbifli : which fhews both the goodnefs of the Stone , and 
the carefulnefiof the Workmen* And in divers places there 
are little Pools of Water, perhaps made onpurp^^f^for Beafts 
to drink, and to ferve for other ufes in time of ne^d: For in 
no place almoft are there any Droppings to be (een , • nor are 
the Walks at all wet under- foot, only it fecms 3 that Rain 
gets in by t\\Q Alr-Jhrfts^ which,for favingof labour, and per- 
haps too, to make thefe Pools, are let down from fuch places 
commonly, as are the Pools thereabout 5 and fo the Rain5that 
falls on the higher grounds, does eafily find the way thither* 
An Account of (bme Books. 
\. tRACTS mritten by the Honour ableKohtxt^oyXt^ of a Dif- 
covery of the Mm\x2h\t RAREFAC7I0N of the AIR {even 
mihout Heat:) New Ohfervations about the PVRATION of 
the SPRING of the AIR : New Experiments touching the CON- 
DENSATION of the Air by meer COLD and its COMPRES- 
SION without Mechanical Engins : And the admrably DIF- 
FERING EXTENSION of the jame;^antity of Air rarifyed 
and €ompreJJtd, hondoh^for H. Herringman,i'670. 4°. 
^^HE main drift of thefe Excellent Tr/^^?/ is, to invite 
J_ the Curious to obferve the ftupendious Mutability of 
the Airy as to Rarity.and Denfity, whereby the fame Quantity 
of Air, being'fometimescdmprefs'd, fometimes dilated, may 
change its Dimenfions to a degree , that feems atooft to tran- 
fcend the power of Nature^nd Art, andmightbe look't upoa 
as incredible, if it were abruptly and nakedly propofed y or 
by a perlbn of only common Ikill in thefe matters* 
