,nature's ,miracles  ,familiar ,talks on
 ,science  ,,by  ,,elisha ,,gray1 ,,ph4 
,d41 ,,ll4 ,d4  ,,vol4 ,i               
,world-,building and ,life  ,,earth1    
,,air1 ,,and ,,water  ,,new ,,york      
,,fords1 ,,howard1  ,,hulbert           
,,copyright1 #ahii1  ,,by  ,,fords1     
,,howard  ,,hulbert4  ,,the ,,mershon   
,,company ,,press1 ,,rahway1 ,n4 ,j4    
,,contents4   ,,chapter                 
,,page  ,,introduction1                 
v      ,,earth4     ,i4                 
,,world-,,building ,,and ,,life1        
#a     ,,ii4 ,,limestone1               
#ab     ,,iii4 ,,coal1                  
#bb     ,,iv4 ,,slate ,,and ,,shale1    
#ca     ,v4 ,,salt1                     
#cf      ,,air4     ,,vi4 ,,the         
,,atmosphere1                           
#db     ,,vii4 ,,air ,,temperature1     
#ea     ,,viii4 ,,cloud ,,formation1    
#fj     ,,ix4 ,,cloud ,,formation       
7,continued71                    #fi    
,x4 ,,wind--,,why ,,it ,,blows1         
#gi     ,,xi4 ,,wind 7,continued71      

#hh     ,,xii4 ,,local ,,winds1         
#ajj     ,,xiii4 ,,weather              
,,predictions1                          
#aaj     ,,xiv4 ,,how ,,dew ,,is        
,,formed1                               
#aae     ,,xv4 ,,hailstones ,,and       
,,snow1                             #abd
     ,,xvi4 ,,meteors1                  
#abi     ,,xvii4 ,,the ,,sky ,,and ,,its
 ,,color1                         #acd  
,,xviii4 ,,liquid ,,air1                
#adf      ,,water4     ,,xix4 ,,rivers  
,,and ,,floods1                         
#aeb     ,,xx4 ,,tides1                 
#afa     ,,xxi4 ,,what ,,is ,a ,,sponge8
                               #afg     
,,xxii4 ,,water ,,and ,,ice1            
#agg     ,,xxiii4 ,,stored ,,energy ,,in
 ,,water1                       #ahb    
,,xxiv4 ,,why ,,does ,,ice ,,float8     
#aib     ,,xxv4 ,,glaciers1             
#aih     ,,xxvi4 ,,evidences ,,and      
,,theories ,,of ,,an ,,ice ,,age1       
#bjg     ,,xxvii4 ,,glacial ,,and       
,,preglacial ,,lakes ,,and ,,rivers1    

#bag     ,,xxviii4 ,,some ,,effects ,,of
 ,,the ,,glacial ,,period1          #bcj
     ,,xxix4 ,,drainage ,,before ,,the  
,,ice ,,age1                   #bci     
,,introduction4   ,dear ,reader3 ,please
 look through this ,introduction before 
beginning with the regular chapters4 ,it
 is always well to know the object1 aim1
 and mode of treatment of a book before 
reading it1 so as to be able to look at 
it from the author's view-point4        
,first3 ,a word about the               
title--,nature's ,miracles4 ,some may   
claim that it is unscientific to speak  
of the operations of nature as miracles4
 ,but the point of the title lies in the
 paradox of finding so many wonderful   
things--as wonderful as any miracle that
 was ever recorded--subservient to the  
rule of law4  ,but1 you say1 a miracle  
does not come under any rule of law4    
,ah6 are you sure of that8 ,it is true  
that we may not understand the law that 
the so-called miracle comes under1 but  
the ,author of all natural law does4 ,we

 do not pretend to dispute but that the 
,power that made nature's laws can      
change them if ,he sees fit2 but we     
cannot believe that ,he will ever see   
fit4 ,it would destroy all order and    
harmony1 all advancement in science and 
knowledge of ,god's works1 not to be    
able to rely implicitly upon the laws of
 nature as consistent and continuous4   
,in putting out these little volumes1 it
 is not to be understood that the       
subjects treated will be more than      
touched upon1 at the most salient       
points4 ,to do much more would require  
volumes of immense size1 and life would 
be too short for me to write or for you 
to read them4  ,again3 these volumes are
 familiar talks4 ,the ,author wishes to 
sit down with you--so to speak--and not 
hold you at arm's length4  ,it will be  
his aim to use the language of common   
life and to avoid all technical names so
 far as possible1 or1 when they are     
necessary1 to explain their meaning4    
,the object is to reach the thousands of

 readers who have not and cannot have   
the advantages of a scientific          
education1 but who can by this means get
 at least a rudimentary idea of some of 
the natural laws with which they are    
coming in contact every hour1 and       
through which the inner man has constant
 communication with the outer world4 ,it
 may be1 too1 that many young students  
will be helped by these plain general   
views of topics which their text-books  
will give them in detail4  ,a knowledge 
of the real things in the objective     
world about us and the laws that govern 
them in their inter-relations is of     
practical value to every man1 whatever  
his calling may be4 ,not only will it be
 of value practically1 but it will also 
be a constant source of interest and    
pleasure4 ,man is so constituted that he
 must have something to be interested   
in1 and if he has no resources within   
himself he looks elsewhere1 and often to
 his hurt1 mentally1 morally1 or        
otherwise4 ,if he could have an interest

 awakened in him for the study and      
contemplation of the natural world he   
would then have a book to read that is  
always open1 always fresh1 always new4  
,he is dealing with facts and not       
theory1 except as he uses theory for    
getting at facts4  ,a man who is all    
theory is like a rudderless ship on a   
shoreless sea4 ,all he really knows is  
that he is afloat1 and if he lands at   
all it is likely to be in an insane     
asylum4 ,the mind1 in order to keep its 
balance1 must have the solid foundation 
of real things4 ,theories and           
speculations may be indulged in with    
safety only so long as they are based on
 facts that we can go back to at all    
times and know that we are on solid     
ground4  ,it is the desire and aim of   
all good men to make their nation a     
truly great people1 with a civilization 
the highest possible4 ,the character of 
all kinds of growth is largely          
determined by the character of the      
material upon which it feeds4 ,the study

 of natural law can never be harmful1   
but is always beneficial1 for the       
student is then working in harmony with 
law4 ,it is the violation of law that   
makes all the trouble in the            
world--whether physical1 moral1 or      
social4 ,when we speak of natural law we
 do not confine ourselves to what is    
commonly known as chemistry and physics1
 and the laws that govern the material  
world1 but include as well the laws of  
our own being1 as intellectual and      
spiritual units4 ,for all law1 physical1
 intellectual1 and spiritual1 is in a   
sense natural4  ,all departments of     
science are simply branches of one great
 science1 and all phases of human       
activity are touched by it4 ,the        
preacher is a better preacher1 the      
doctor a better doctor1 the lawyer a    
better lawyer1 the editor a better      
editor1 the business man a better       
merchant1 and the mechanic a better     
workman1 if they follow scientific      
methods4 ,indeed1 any man will be a     

better husband1 father1 and citizen1 if 
he has some trustworthy knowledge of the
 laws under which this great universe1  
down to his own little part of it1      
lives1 moves1 and has its being4        
,,nature',s ,,miracles4     ,,earth4    
,,chapter ,i4  ,,world-,,building ,,and 
,,life4   ,in the beginning ,god created
 the heaven and the earth4 ,and the     
earth was without form1 and void4       
,whatever our speculations may be in    
regard to a beginning1 and when it was1 
it is written in the rocks1 that1 like  
the animals and plants upon its surface1
 the earth itself grew2 that for        
countless ages1 measured by years that  
no man can number1 the earth has been   
gradually assuming its present form and 
composition1 and that the processes of  
growth and decay are active every hour4 
,the science that deals with the        
formations and stratifications that are 
found on the earth and under the earth1 
and all the forces that have been and   
are now active in their formation1 is   

called ,geology 7earth science74 ,it is 
a science about which little is known by
 the average individual1 and yet it is  
one of transcendent interest1 from the  
study of which the lover of nature can  
obtain a vast amount of profit and      
pleasure4 ,when the uncultured man sees 
a stone in the road it tells him no     
story other than the fact that he sees a
 stone and that it would better be      
removed2 and all the satisfaction he    
gets out of it is in the thought that he
 has saved some unlucky wagon wheel from
 being wrenched or broken4 ,the         
scientist looking at the same stone     
perhaps will stop1 and with a hammer    
break it open1 when the newly exposed   
faces of the rock will have written upon
 them a history that is as real to him  
as the printed page4 ,he is carried back
 to a far-off time1 where he sees the   
processes and forces at work that have  
formed this stone and made it what it   
is1 not only in its outward form1 but in
 its constitution1 down to its molecules

 and atoms4 7,the word atom is used in  
chemistry to mean the smallest particle 
of an elementary substance that will    
combine with the atoms of another       
substance to form new compounds of      
matter4 ,and molecules are made up of   
atoms47 ,the scientist looking at this  
stone sees in it not only that          
mechanical and chemical agencies have   
cooperated in the work of its formation1
 but that animal life itself may have   
been the chief agency in bringing the   
materials together and giving form to   
the peculiar architecture employed in   
its formation4 ,if it is a piece of     
limestone this latter statement will be 
eminently true4  ,here is a powerful    
motive for the study of physical        
science4 ,it is not to be expected1 nor 
is it possible1 that every individual   
can be a scientist in the strict sense  
of the word1 but it is possible for     
everyone of ordinary intelligence to    
become familiar with the salient facts  
of science1 if only a small portion of  

the time that is now devoted to the     
reading of literature that is rather    
harmful than helpful be spent in        
studying the phenomena and works of     
nature4  ,the acquirement of such       
knowledge would furnish every individual
 with a constant source of instructive  
amusement that would never lose its     
interest4 ,he would not be dependent    
every hour upon people and things       
outside of himself2 because he would    
carry about with him inexhaustible      
sources of instruction and pleasure that
 would furnish him continual and helpful
 diversion and save him from a thousand 
morbid tendencies that are always ready 
to seize upon an unemployed mind4 ,there
 are many men and women in the insane   
asylum to-day for the simple reason that
 they have not made intelligent use of  
the mental powers that nature has       
endowed them with4  ,sermons are not    
always preached from pulpits4 ,they are 
written in the rocks and on the flowers 
of the field and the trees of the       

forest4  ,let us then look a little at  
the underground foundation of all this  
beautiful earth4 ,and before attempting 
that1 the question may arise in some    
minds how we know what is so deep down  
under the surface4 ,fortunately this is 
a question very easily answered4 ,at    
some period after the rocks were formed 
the crust of the earth was broken by    
volcanic eruptions at various places and
 times1 and turned up1 as in the        
formation of mountains1 so that the     
edges of the various stratifications of 
the rocks1 from those near the surface  
down to the lowest rocks1 are exposed to
 view4 ,another means of knowing what   
the various formations are has been by  
borings of deep wells4 ,these borings1  
however1 are only confirmatory of what  
was well known before through the       
upheavals that are plentiful in all     
parts of the world4 ,there is abundant  
evidence that all of the rocks and all  
of the strata of every name and nature  
7except perhaps igneous rocks7 were     

originally laid down in water4 ,this is 
evidenced not only by the               
stratifications themselves1 but by the  
evidences of sea-life everywhere present
 in the earth's crust4 ,before the      
upheavals in the earth's crust began1   
the whole surface of the globe was a    
great ocean of hot water4 ,the          
substances of which the rocks were      
formed were undoubtedly held in         
suspension in the air and in the water1 
and by a gradual process were deposited 
in the bottom of the ocean in layers1   
forming rocks of various kinds1         
according to the nature of the substance
 deposited4 ,gradually the crust of the 
earth was built up until it acquired a  
certain thickness2 when1 either from    
shrinkage under the crust a great void  
was formed until it could not sustain   
its own weight1 or the pressure caused  
by confined gases and molten matter     
produced an upheaval which broke the    
crust of the earth outward1 causing     
great wrinkles that we call mountain    

ranges4 ,undoubtedly both forces were   
active in producing these results4 ,when
 the gases and molten matter had escaped
 through the rifts in the rocks caused  
by the upheaval there must have been    
great voids formed that were filled up  
by the shrinkage of the earth1 causing  
much irregularity in its surface4  ,in  
some places there were enormous         
elevations1 and in others               
correspondingly deep depressions4 ,the  
water that before was evenly distributed
 over the surface of the globe1 after   
the upheavals ran off into the lower    
levels1 filling up the great valleys1   
forming the seas1 and leaving about     
one-third of the land surface uncovered4
 ,it must not be supposed1 however1 that
 the appearance of the land was caused  
by one grand movement or upheaval1 but  
that it has been going on in successive 
stages through long ages of time4 ,this 
is clearly evidenced by the rock        
formations4 ,the deposition of rock     
strata is still active in the bottoms of

 the oceans1 although not to the same   
degree as in former times4 ,when the    
upheaval took place the old             
stratifications were thrown out of      
level1 but the new ones that were then  
formed remained in a level position     
until they were in their turn disturbed 
by some subsequent upheaval4  ,the laws 
of gravitation would tend to precipitate
 the matter held in suspension by the   
water straight down to the bottom1      
toward the center of the earth1 so that 
the plane of these stratifications would
 tend to be parallel to the surface of  
the water1 that is horizontal1 until    
disturbed4 ,then they would be tilted in
 many directions4 ,hence it will be     
easily seen why the seams in the rocks1 
especially in and near mountainous      
regions1 do not lie in a horizontal     
position after an upheaval1 but are     
found standing at all angles1 up to a   
perpendicular4  ,viewed from this       
standpoint1 the solid portion of the old
 world has gone all to pieces4 ,wherever

 there is a chain of mountains it marks 
a breakage in the earth's crust1 and    
these mountains are not all on the land1
 but extend under the seas so deeply    
that they are unable to lift their heads
 above the surface of the water4 ,the   
earth is no longer round1 except in     
general outline1 but broken up into all 
sorts of shapes that give the varied    
conditions of landscape that we find    
whichever way we turn4  ,there are but  
few volcanoes that are active in this   
age1 while in former times they extended
 for thousands of miles4 ,we still have 
occasional earthquakes1 but undoubtedly 
they are very slight as compared with   
those that shook the earth millions of  
years ago4  ,if1 now1 we study the      
constitution of the earth's crust so far
 as it has yet been penetrated1 we find 
it divided up into periods called       
,primary1 ,secondary1 and ,tertiary4    
,the primary period reaches down to the 
line where the lowest forms of animal   
fossils begin to be found4 ,this is     

called the ,paleozoic period1 which     
means the period of ancient life4 ,from 
here let us first go downward4          
,immediately under this lies a stratum  
of ,metamorphic rocks4 ,to metamorphose 
is to change2 and metamorphic rocks are 
those which have been changed by heat or
 pressure from their original formation4
 ,this class of rocks lie on top of what
 are called ,igneous rocks1 which means 
that they have been formed by or        
subjected to heat4 ,all lava-formed     
rocks are igneous4 ,they are            
unstratified1--not in layers or strata1 
but in a formless mass1--and in this    
they differ from water-formed rocks4    
,if there is a molten center to the     
earth these igneous rocks are           
undoubtedly the offspring of this great 
internal furnace4 ,the metamorphic rocks
 were primarily igneous and are changed 
somewhat in their structure by the lapse
 of time4 ,for instance1 marble is a    
metamorphic limestone4 ,the difference  
between common limestone and marble is  

in its molecular structure--the way in  
which its smallest particles are put    
together4 ,they are both carbonates of  
lime4 ,but the marble is made up of     
little crystals and will take a polish1 
while ordinary uncrystallized limestone 
will not4 ,the igneous rocks are chiefly
 granite2 and granite is formed of      
orthoclase-feldspar1 mica1 and quartz4  
7,the word orthoclase means straight    
fracture1 and the orthoclase-feldspar   
has two lines of cleavage at right      
angles to each other47 ,this is the     
ordinary composition of granite1 but    
there are a great many variations1      
chiefly as to color and proportions of  
the ingredients named4  ,the igneous    
rocks1 then1 are the lowest of all2 then
 come the metamorphic rocks2 and as     
before stated1 on top of metamorphic    
rock begins the first evidence of life  
in its lowest form4 ,the ,paleozoic     
7ancient life7 or ,primary period is    
made up of a number of subdivisions4    
,the first and oldest division is called

 the ,silurian age1 which is underlaid  
by the metamorphic rocks and overlaid by
 the rocks of the ,devonian period4 ,it 
is called ,silurian1 from the name of a 
kind of fish1 fossils of which are found
 in the rocks of this age1 which are    
distinguished for the absence of        
land-plant fossils and vertebrate       
animals4  ,in the ,silurian strata are  
found limestones1 slate1 flagstones1    
shales1 etc4 ,on top of the ,silurian   
begins the ,devonian age1 in which is   
found the old red sandstone1 as well as 
limestone and slate2 and here begin to  
be found the fossils of land-plants4 ,on
 top of the ,devonian lies the          
,carboniferous series1 which complete   
the series of the primary period4 ,in   
the lower part of this stratum is found 
carboniferous limestone1 which is       
overlaid by a kind of stone called      
millstone grit1 and on top of this lie  
the true carboniferous strata or        
coal-bearing measures4 ,in the coal     
strata are found the first reptile      

fossils4  ,on top of the coal measures  
begins the ,secondary period1 or        
,mesozoic 7middle life74 ,this period is
 distinguished for the great development
 of reptiles1 and is called the age of  
reptiles4 ,in this age occur the first  
traces of mammals1 and birds1 and fishes
 with bony skeletons4 ,among plants we  
find here the first evidence of palms4  
,the formation is chiefly chalk1        
sandstones1 clays1 limestone1 etc4 ,we  
now come to the last or ,tertiary       
period1 which brings us to the top      
earth4 ,this is chiefly formed of       
sedimentary rocks--those which have been
 formed by the settling of sediment1 in 
water4  ,while we are forced to these   
general conclusions in regard to the    
building of the world1 and to its       
subsequent distortion by the series of  
upheavals that have occurred from time  
to time1 and to the successive ages of  
the layers of rock foundation of its    
crust1 there are many mysteries that    
remain unsolved and many questions will 

present themselves to the mind of the   
reader4 ,one of these questions is1     
,where was the water and where was the  
earthy matter before its precipitation8 
,matter1 including water1 can exist in  
the gaseous form1 and we only need to   
assume that there was a core of intense 
heat1 to understand how all the material
 that we find on the earth and in the   
earth could have been held in suspension
 in the gaseous state until the cooling 
process had reached a stage where the   
various combinations and recombinations 
could take place in the great laboratory
 of nature4 ,if we study the            
constitution of the sun 7and with the   
modern appliances we are able to do so71
 we find that it is made up of some and 
perhaps all of the same materials that  
are found here on earth4 ,if there is no
 water existing1 in the sun1 as water1  
there are the gases present which would 
produce it if the conditions were right4
 ,and1 for all we know1 that flaming    
mass of burning gases may some time go  

through the same kind of cooling and    
building up in solids that our earth has
 experienced4  ,we thus have what may be
 called an outline sketch of the process
 of ,world-building4     ,,chapter ,,ii4
  ,,limestone4   ,a large part of the   
structure of the earth's crust is formed
 of a substance called limestone4       
,ordinary limestone is a compound of    
common lime and carbon dioxide1 a gas   
that is found mixed with the air to a   
very small degree4 ,carbon dioxide will 
be better known by the older people as  
carbonic acid4 ,it is a gas that is     
given off whenever wood and coal are    
burned1 or any substance containing     
carbon4 ,it is composed of one atom of  
carbon to two of oxygen4 ,every ton of  
coal that is burned sends off three and 
two-thirds tons of this gas4 ,the       
increase in weight comes from the fact  
that every atom of carbon unites with   
two of oxygen1 which it takes from the  
air1 and the oxygen is heavier than the 
carbon4  ,in comparing the relative     

weights of atoms 7the smallest          
combinable particle of a solid1 liquid1 
or gas7 we use the hydrogen atom as the 
unit of comparison and call it one1     
because it is the lightest of all atoms4
 ,the carbon atom is twelve times       
heavier than the hydrogen atom1 and the 
oxygen atom is sixteen times heavier4   
,hence it will be seen readily how a ton
 of coal will form two and two-thirds   
times its weight of carbonic dioxide4   
,lime1 having a strong affinity or      
attraction for this gas1 has absorbed it
 from the air and water1 forming what is
 known as carbonate of lime--which is   
the ordinary limestone4 ,chalk and the  
various marbles are also carbonates of  
lime4 ,limestone strata in the crust of 
the earth are found in all the periods  
of the earth's formation4 ,all forms of 
sea shells that were once the homes of  
animal life are constructed of this     
compound2 and in the later formations of
 limestone1 in the ,secondary and       
,tertiary periods1 we find this rock to 

be made up almost entirely of marine    
shells1 some of them microscopic in     
size4 ,the earlier or older formations  
of limestone that are found deeper down 
in the earth's crust are less mingled   
with these marine shells4 ,this comes   
from the fact that the first deposition 
of limestone strata occurred before the 
later forms of sea life had developed4  
,whatever signs of life are found in    
these lower stratifications are of the  
very lowest order4 ,it is not to be     
understood that animal life is a        
necessary factor in the formation of    
limestone1 but it has been an incidental
 feature which no doubt has been the    
chief means of gathering up from the    
water this compound and precipitating it
 into the great limestone strata that   
are everywhere found4  ,carbonate of    
lime is found in solution in nearly1 if 
not quite1 all of the mineral waters1   
and is also found in the water of the   
ocean4 ,in earlier times it must have   
been held in solution in much greater   

quantities than at present4 ,the myriads
 of sea animals that existed1 and that  
still exist1 gathered from the water    
this substance1 which formed their      
shells1 and served as a house in which  
they lived4 ,new germs were continually 
forming new shells1 while the older ones
 ceased to live as animals1 and their   
houses in which they lived were         
precipitated to the bottom of the ocean1
 where they were bound together as      
limestone rock4 ,these sea animals no   
doubt caused a much more rapid formation
 of limestone than would or could have  
been the case without their existence4  
,one can thus readily see what an       
important factor animal life has been in
 the process of world-building4 ,this   
process is still going on1 but probably 
not to the same extent as in former     
ages1 because it is not likely that     
there is so much carbonate of lime held 
in solution as there was before these   
great limestone beds were formed4       
,limestone1 however1 is easily          

disintegrated by the action of water4   
,we find the spring water impregnated   
with it as well as that of the small    
streams and rivers4 ,pure water is a    
powerful solvent4 ,when the rains fall  
upon the earth the water percolates     
through it and through the limestone    
strata1 which gradually wears away the  
limestone and carries it back to the    
ocean1 so that the process of tearing   
down and building up is continually     
going on4 ,the great caves that are     
found everywhere in the limestone       
regions were formed by the action of    
water4 ,the great ,mammoth ,cave of     
,kentucky1 which is said to have #bjj   
miles of underground passages1 has been 
entirely worn out by the action of      
running water4  ,some years ago the     
writer visited this cave and had an     
opportunity to study the wonderful      
eroding or gnawing-out effect of water  
on limestone4 ,at some period earlier in
 the history of the earth there was     
evidently an underground river or large 

stream of water that found its way      
through the crevices of the rocks1 and  
gradually wore out a great bed for      
itself1 which was fed by lateral streams
 pouring into the main branch1 each one 
of which lateral branches cut its own   
channel4 ,a plan view of the ,mammoth   
,cave presents a picture not unlike that
 of a great river with numerous branches
 emptying into it1 all of them showing  
the windings such as we see in a river  
and its feeders upon the surface of the 
earth4 ,there are three sets of these   
channels1 one above the other1 and we do
 not find the water till we get to the  
bottom of the third underground story1  
so to speak4 ,there is one place in this
 system of underground channels where   
the dripping from the roof of the upper 
channels has cut a great well hole many 
feet in diameter perpendicularly down   
through the whole system to a great     
depth4 ,the sides of this great well    
hole are fluted into grooves caused by  
the constant downflow of the water4     

,although the amount of water flowing   
down through this well hole is very     
small1 it is continually at work4 ,like 
interest on money1 it never rests1 each 
minute that passes has eaten away some  
of the great rock4  ,in other portions  
of the cave the dripping of the water is
 so gradual that the carbonate of lime  
hardens and forms what are called       
stalactites1 that hang like icicles from
 the roof of the cave4 ,sometimes the   
water runs down so slowly upon these    
stalactites that it evaporates as fast  
as it appears1 leaving behind its little
 load of carbonate of lime4 ,if1        
however1 there is a drip1 there are     
formations built also from the lime in  
the dropping water on the floor of the  
cave1 and these are called stalagmites4 
,in time the stalactites and the        
stalagmites will meet1 forming a great  
column reaching from floor to ceiling4  
,some of these formations1 when they are
 free from foreign substances1 are very 
beautiful4 ,they are also very hard1    

giving off a metallic musical tone when 
struck by any hard substance4  ,we have 
already stated that limestone is a      
compound of ordinary lime and carbon    
dioxide1 forming a carbonate of lime4   
,this statement does not give a complete
 analysis of all the elements entering  
into limestone4 ,in the first place lime
 itself is a compound formed of two     
elementary substances1 calcium and      
oxygen4 ,the lime molecule is composed  
of one atom of calcium and one of       
oxygen4 ,neither calcium nor lime is    
found pure in nature4 ,inasmuch as      
carbon dioxide is composed of one atom  
of carbon and two of oxygen1 and lime is
 composed of one atom of calcium and one
 of oxygen1 when we have the two        
combined the molecule of carbonate of   
lime1 or1 as it is technically called1  
calcic carbonate1 is composed of one    
atom of calcium1 one of carbon and three
 of oxygen1 7lime plus carbon dioxide74 
,as before stated1 lime is not found    
un-combined with other substances in    

nature4 ,and as it is of great economic 
importance1 it will be profitable to    
know how it is formed4 ,lime is produced
 from ordinary limestone by burning it  
in kilns where it is subjected to a heat
 of a certain temperature for a number  
of hours4 ,the heat drives off the      
carbon dioxide1 which1 as we have seen1 
has taken away from each molecule of the
 compound all of the carbon and two     
atoms of the oxygen1 while all of the   
calcium is retained with one atom of    
oxygen1 leaving ordinary lime4 ,lime1   
then1 is simply oxide of calcium4  ,as  
all know1 it is used almost exclusively 
for making mortar for building purposes4
 ,in order to do this we have to put it 
through the process of slacking1 by     
pouring water upon it1 and here another 
chemical change takes place4 ,the water 
unites with the lime1 when immediately  
the heat that was expended in throwing  
off the carbon dioxide and was stored in
 the lime as energy is now given up     
again in the form of heat4 ,when a      

considerable bulk of lime is slacked    
very rapidly the heat that is given off 
is so great that it will produce        
combustion4 ,here is a beautiful        
illustration of what has been           
erroneously called latent heat4 ,it is  
heat stored as potential energy1 that is
 released by the combination of lime    
with water4 ,slackened lime1 then1 is   
called calcic hydrate4  ,very little of 
the limestone that we find is absolutely
 pure4 ,it is considered good when it   
does not contain over five or six per   
cent4 of foreign substance4 ,when more  
than this is present the lime is        
considered poor1 and when it reaches    
fifteen per cent4 or more of impurities 
it assumes the property of hardening    
under water and is called cement4       
,carbonate of lime is found in several  
other forms2 for instance1 the various  
kinds of marble and chalk are carbonates
 of lime4 ,the composition of marble and
 chalk is exactly the same as that of   
limestone4 ,the difference is chiefly   

one of molecular rather than chemical   
structure4 ,marble is what chemists     
would call an allotropic or changed form
 of limestone2 and1 as before stated1   
the difference seems to consist in the  
fact that the marble assumes a          
crystalline arrangement of its atoms and
 will therefore take a high polish1     
which is not true of ordinary limestone4
 ,marble varies greatly in coloring and 
texture1 all of which differences are   
explainable under the one head of       
molecular arrangement4 ,nearly pure     
carbon exists in three distinct         
forms--the diamond1 graphite1 and       
charcoal4 ,as is the case with marble1  
these differences in the different forms
 of carbon are not chemical1 but        
molecular differences4 ,the substances  
are the same1 but their infinitesimal   
particles are differently arranged4     
,carbonate of lime--as it exists in its 
various forms1 as limestone1 from which 
lime and cement are made1 and marble1   
which is such an important element in   

the arts--is a substance of great       
importance to man4 ,we have already     
noted some of the processes that nature 
uses in gathering up these substances   
from the ocean by the employment of     
various forms of animal life4 ,here is  
another4 ,whoever has visited the       
,bermudas has seen an island wholly     
formed of what is called coral rock4    
,coral is a structure produced by a     
peculiar form of sea animal that gathers
 up the calcareous or lime-like matter  
floating in the sea water1 and builds a 
house of it in which to live during the 
little lifetime that is allotted to him4
 ,when he dies his children do not      
occupy the old home1 but build a new    
one1 which is a superstructure planted  
upon the old one as a foundation4 ,this 
process of growth sometimes takes the   
form of a tree or plant1 and coral trees
 grow upon trees and plants upon plants1
 until a structure is erected having its
 foundation upon the bottom of the      
ocean1 that finally reaches up until it 

rises above the surface of the water2   
and here--after through years the water 
has brought sea-weed and drift to decay 
and form soil1 and the birds have       
brought seeds and fertilization1 and    
vegetable life is prospering--another   
animal called man builds his home upon  
it4 ,the material that the coral is     
formed of is substantially the same as  
that we find in the minute shells of the
 limestone rocks4  ,the great chalk     
cliffs that are found on the coasts of  
the ,english channel are the work of a  
sea animal microscopic in size4 ,at one 
time it was a question among scientists 
how these chalk cliffs were formed1 but 
when the microscope was invented this   
mystery1 as well as many others1 was    
solved4 ,the chemical components of     
chalk are precisely the same as those of
 limestone4 ,the microscope shows that  
chalk is almost wholly a product of very
 small organized shells4 ,the animals   
who are the architects of the chalk     
cliffs are called foraminifera--bearing 

shells perforated with little holes4    
,the chief difference between chalk and 
limestone seems to be in the size of the
 shells of which they are respectively  
made up and in the manner of the bonding
 of these shells together4 ,the shells  
in a lump of chalk are held much more   
loosely than those in a lump of         
limestone4 ,these intrepid workers are  
still actively changing the structure of
 the bottoms of seas and oceans1 and    
forming new islands1 which in turn      
become the substructure that supports   
new life1 animal and vegetable4 ,and    
when we consider the great part         
performed by these microscopic          
architects and builders it is not a     
misnomer to speak of the building of a  
world4     ,,chapter ,,iii4  ,,coal4    
,some time1 long ago1 some man made the 
discovery that what we now call coal    
would burn and produce light and warmth4
 ,who he was or how long ago he lived we
 do not know1 but as all earthly things 
have a beginning1 we know that such a   

man did live and that the discovery that
 coal would burn was made4 ,coal1 in the
 sense that we use the word here1 is not
 mentioned in the ,scriptures4          
,according to some authorities1 coal was
 used in ,england as early as the ninth 
century4 ,it is recorded that in #abei  
,king ,henry ,,iii4 granted a privilege 
to certain parties to mine coal at      
,newcastle4 ,it is further stated that  
seven years after this time coal became 
an article of export4 ,in #acjf coal was
 so generally used in ,london that a    
petition was sent to parliament to have 
the use of it suppressed on the ground  
that it was a nuisance4 ,coal was used  
in ,belgium1 however1 about #abjj4      
,there is a tradition that a blacksmith 
first used it in ,liege as fuel4 ,it was
 first used for manufacturing purposes  
about #agac4  ,coal is found laid down  
in great veins1 varying in thickness1 in
 various parts of the world in the upper
 strata of the ,paleozoic period4 ,the  
age in which it was formed is called by 

geologists the ,carboniferous           
7coal-bearing7 age4  ,before going on to
 account for the deposits of coal1 let  
us stop a moment and consider what it   
is4 ,chemists tell us that coal is      
chiefly constructed of carbon1          
compounded with oxygen1 hydrogen1 and   
nitrogen4 ,there are many varieties1 but
 all may be classified under two general
 headings--bituminous and anthracite4   
,bituminous coal contains a large amount
 of a tarry substance1 a kind of mineral
 pitch or bitumen1 which burns with a   
brilliant flame and a black sooty smoke1
 exceedingly rich in carbon4 ,anthracite
 coal is hard and stone-like in its     
texture1 burning with scarcely any flame
 and no smoke4 ,it produces a fire of   
intense heat when it is once ignited4   
,there is another form of coal called   
cannel coal1 which is a corruption of   
candle coal1 so called because a piece  
of this kind of coal when ignited will  
burn like a match or pine knot and give 
light like a candle4 ,this is the       

richest of all the coal deposits in     
gases that are set free by heat1 and for
 this reason is extensively used in the 
manufacture of what is commonly called  
coal gas4 ,england produces a large     
amount of cannel coal1 as well as       
another variety of bituminous coal1     
which latter1 however1 does not burn    
with such a black smoke as the coal     
found in the ,ohio valley and the       
,western ,states of ,america4 ,east of  
the ,alleghany ,mountains there is a    
region of anthracite coal that is very  
extensively worked and finds great favor
 in all parts of the country as fuel for
 domestic heating1 especially on account
 of its great cleanliness4  ,all of the 
coal beds have a common origin1 and the 
difference in the quality of coal found 
in different parts of the country is due
 to many circumstances1 some of which   
have never been explained4 ,there is    
indisputable proof1 however1 that all   
coal beds are of vegetable origin4      
,geologists tell us that these coal beds

 were formed during an age before the   
earth had cooled down to the temperature
 that it has at the present time--an age
 when vegetation was forced by the      
internal heat of the earth instead of   
having to receive all its warmth from   
the sun's rays as we do now4 ,some of   
our readers are familiar with what is   
commonly termed a hotbed4 ,a hotbed is  
made by putting soil on top of          
substances that will ferment and create 
heat underneath the soil4 ,this heat    
from beneath will force vegetation and  
cause a much larger growth than there   
will be if left to the sun's rays alone4
 ,during the carboniferous age the earth
 was a great hotbed4  ,the fossils of   
trees and plants1 as well as reptiles1  
that we find in the great coal measures 
of the world1 show that they were of    
large tropical growth1 and this is shown
 not only in the temperate zone1 but in 
the zone farther north4 ,for ages and   
ages this rank growth of vegetation grew
 up and fell down until a great layer of

 vegetable matter was formed1 which at a
 later time was covered over by other   
stratifications of earth material1 so   
that these great layers of vegetable    
formation were hermetically sealed and  
pressed down by an enormous weight that 
increased as time went on4 ,the         
formation of coal may be studied even at
 this day 7for it is now going on7 by   
visiting and examining the great peat   
beds that are found in various parts of 
the world4 ,it is well known that peat  
is used as a fuel by many people1       
especially the peasantry of the old     
countries4 ,if peat is pressed to a     
sufficient degree of hardness it burns  
in a manner not unlike some forms of    
coal4 ,peat is a vegetable formation and
 has been formed by the rank growth of  
various kinds of vegetation in swampy   
places4 ,of course1 it lacks the purity 
of the coal that was formed during the  
carboniferous age1 because of the much  
slower growth of vegetation now than    
during that time1 and the opportunity   

that peat bogs offer for an intermixture
 of earthy with the vegetable matter4   
,the fact that we find the imprint of   
trees and ferns and other vegetable     
growth of tropical varieties1 as well as
 the fossils of reptiles1 imbedded in   
the coal measures1 proves that at one   
time this stratum was at the land       
surface of the earth4 ,we also find that
 all of the formations of the ,secondary
 and ,tertiary periods are on top of the
 coal--and this shows that after the age
 of rank vegetable growth there was a   
sinking of the earth in many places far 
down into the ocean--so that vast layers
 of rock formed on top of these beds of 
vegetable matter4 ,in ,england great    
chalk beds crop out in cliffs on the    
southern coast1 and1 as we have seen1   
these chalk rocks are largely made up of
 the shells of marine animals4 ,london  
stands on a chalk bed1 from six hundred 
to eight hundred feet thick4 ,indeed1   
,england has been poetically called     
,albion1 ,white-land1 from this         

appearance of her coast4  ,all of the   
great chalk beds were formed ages after 
the coal beds1 as the latter are found  
in the upper strata of the ,paleozoic   
period4  ,a study of these strata will  
show that there are many layers of coal 
strata varying in thickness and         
separated by layers of shale and        
sandstone4 ,how the shale and sandstone 
layers are formed will be the subject of
 a future chapter4  ,from the position  
that the coal measures occupy1 being    
entirely under the ,secondary and       
,tertiary formations1 it will be        
observed that they are very old4 ,if we 
should examine a piece of ordinary      
bituminous coal we should find that     
there are lines of cleavage in it       
parallel to each other1 and that it is  
an easy matter to separate the lump on  
these lines4 ,if we examine the outcrop 
of a coal bed we will find that these   
lines of cleavage are horizontal4 ,this 
indicates that the great bulk of        
vegetable matter of which the coal      

formation is made up has been subjected 
to tremendous pressure during a long    
period of time4 ,if we further examine  
the structure of a body of coal we find 
the impressions of limbs and branches as
 well as the leaves of trees and various
 kinds of plants4 ,we shall further find
 that these impressions lie in a plant  
in the same direction as the line of    
cleavage4 ,this is a point to be        
remembered1 as it helps to explain the  
nature and structure of other formations
 than those of coal4 ,not only are      
leaves and branches of vegetable matter 
found1 but fossils of reptiles1 such as 
live on the land4 ,sometimes there is   
found the fossil of a great tree trunk  
standing in an erect position1 with its 
roots running down into the rock below  
the coal bed1 while the trunk extends   
upward entirely through the coal and    
high up into the other strata4 ,all of  
these facts lead us to the firm         
conclusion that when the trees were     
grown that formed these beds they were  

above the surface of the ocean4 ,this1  
taken in connection with the fact that  
the vegetable fossils that are found    
indicate a tropical growth of great     
size1 drives us to the conclusion that  
the climate at the time these coal      
measures were formed was much warmer    
than it is now4  ,as already remarked1  
this extra warmth came from the earth   
itself before it had cooled down to its 
present temperature1 rather than from   
the heat of the sun4 ,there is nothing  
inconsistent in the thought that the sun
 may have been warmer in a former age   
than now4 ,we may conceive that the     
earliest coal formations took place when
 the land stood above the surface of the
 water1 and that the conditions were    
favorable for a rapid and luxuriant     
growth of vegetation2 after this had    
gone on for a very long period of time1 
by some convulsion of nature the land   
surface was submerged under the ocean1  
when other mineral substances were      
deposited on top of this layer of       

vegetable growth1 which hardened into a 
rock formation4 ,at a later period the  
earth was again elevated above the      
surface of the water and the same       
process of growth and decay was         
repeated4 ,these oscillations of the    
earth up and down occurred at enormously
 long intervals1 until all of the       
various coal strata with their          
intermediate formations were completed4 
,after this we must suppose that the    
whole was submerged to a great depth and
 for a very long period of time1 because
 of the great number and various kinds  
of rock formations laid down by water   
that lie on top of the coal measures4   
,this tremendous weight1 as it was      
gradually builded up1 subjected these   
vegetable strata to an inconceivable    
pressure4 ,in some places this pressure 
was much greater than in others1 which  
undoubtedly is one of the reasons why we
 find such differences in the structure 
and quality of coal4 ,there were no     
doubt many other reasons for            

differences1 one of them being the      
character of the vegetable growth out of
 which they were formed4 ,again1 in some
 parts of the world these coal strata   
may have been subjected to a            
considerable degree of heat1 which would
 change the structure of the formation1 
and in some cases drive off the volatile
 gases4 ,one can easily imagine that    
heat was thus a factor in the formation 
of what is known as anthracite coal1 so 
much less gaseous than the bituminous   
kinds4 ,the anthracite beds seem to be  
denser and of a more homogeneous        
character4 ,the lines of cleavage are   
not as prominent1 but there are the same
 evidences of vegetable origin that we  
find in the bituminous formations4  ,it 
will be seen from what has gone before  
that coal was first wood4 ,but wood is a
 product of sunshine4 ,thus the sun was 
the architect and builder of the trees  
and plants that were finally            
hermetically sealed under the great     
earth strata4 ,the sun gathered up the  

material and set the forces in play     
which made the chemical combinations of 
the various elements in nature that     
enter into vegetable growth4  ,after the
 lapse of untold ages of time these     
great beds of stored-up sun-energy were 
discovered by man and their contents are
 dragged out to the earth's surface1 to 
warm our houses1 to drive the machinery 
of our factories1 to send the           
locomotives flying across the continents
 and the steamships over the oceans4 ,so
 important has this article become that 
if any one nation could control the     
output it would be able to paralyze all 
the navies and the manufacturing of the 
world4  ,if the coal of the world should
 become exhausted we should be          
confronted with a great problem4        
,fortunately for us1 this is a problem  
that will have to be solved by the      
people of some future age1 as the growth
 of wood will scarcely keep pace with   
the consumption of fuel4 ,by that time  
the genius of man will have devised an  

economical means of storing the energy  
of the sunbeams directly for purposes of
 heat1 light1 and power4     ,,chapter  
,,iv4  ,,slate ,,and ,,shale4   ,slate  
is one of the great commercial products 
of the world4 ,as far back as the year  
#ahgg the output of slate was not less  
than #a1jjj1jjj tons per annum4 ,the    
chief use to which slate is put is for  
covering buildings1 and for this purpose
 it is better than any other known      
material4 ,it is also used in the       
construction of billiard tables and for 
writing-slates2 these latter uses are   
very insignificant as compared to its   
use in architecture4 ,slate1 like       
building-stone and limestone1 is        
quarried from the earth's crust and is  
found in the strata close above the     
,metamorphic rocks1 near the beginning  
of what is called the ,primary1 or      
,paleozoic period4 ,as compared with the
 coal formations it is very1 very old4  
,there are different substances called  
slate that are not slate in the         

scientific use of that word4 ,in general
 all stone formations are called slates 
that split up into thin layers4 ,but the
 true slate is a special material which 
is formed by special processes of       
nature4 ,the difference between slate   
and shale1 for instance1 is not one of  
ingredients1 but of the process by which
 the ingredients are put together4 ,all 
of the sedimentary rocks are formed by a
 deposit of sediment from the water on  
the bottom of the ocean4 ,at one period 
the floods have brought down a certain  
kind of material in greater profusion   
than at others1 and this is deposited in
 thin layers1 and as it hardens there   
will be seams in it and the             
stratifications will be differently     
colored1 the color depending upon the   
deposit at any particular time4  ,a bed 
of shale1 like a bed of coal1 has lines 
of cleavage in it1 and if it is examined
 under a microscope it will be found    
that the sedimentary particles1 like the
 twigs and leaves in the coal veins1 lie

 with their longest dimensions in line  
with the plane of cleavage4 ,shale in   
color looks like slate1 and an analysis 
of the material of which it is formed   
shows that shale and slate are both made
 from the same4 ,there is1 however1 a   
structural difference between the two   
which is very peculiar and very         
interesting4 ,the slate is ordinarily a 
denser material and the lines of        
cleavage are often at right angles with 
those that we find in ordinary shale4   
,a slab of shale will be of a uniform   
color on any one line of cleavage4 ,the 
color may change at the next line1 and  
generally does1 to a slight extent4 ,it 
is easy to see1 then1 if we could change
 the lines of cleavage in the shale1 so 
as to run at right angles with their    
present lines1 the face of a slab would 
show bands of different colors or       
shadings1 such as we often see in slate4
 ,if you take a piece of clay that has  
been thoroughly mixed1 and subject it to
 a very great pressure1 and then examine

 the piece that has been submitted to   
pressure under a microscope and compare 
it with a piece of the clay after it has
 been thoroughly mixed1 but has not been
 submitted to pressure1 you will find   
that the two are very different in      
structure4 ,the pressed clay will show  
that the particles of which it is made  
up have all turned1 so that their       
longest dimensions are in a line at     
right angles with the direction of      
pressure4 ,here is an interesting fact  
that we must remember4 ,and it is in    
this that we find the reason for the    
structural difference between shale and 
slate4 ,the lines of cleavage in shale  
are not formed necessarily by pressure1 
but because in the disposition of the   
material of which it was formed the     
particles naturally laid themselves down
 so that their longest dimensions were  
on a horizontal line4  ,ages after1 when
 other rock and other formations had    
been laid down on top of the bed of     
deposited mud1 the upheavals of the     

earth have so changed the lines of      
pressure upon this material and the     
pressure is so great that a             
rearrangement of the particles of which 
the slate is made up has taken place1 so
 that their longest dimensions now are  
in a direction that crosses the         
stratifications as originally laid down4
  ,the effect of this is twofold4       
,first1 the material is compressed into 
a denser1 closer form1 and then1 the    
lines of cleavage are changed1 or to    
express it in more common language1 the 
grain has been changed4 ,so that when it
 splits up it runs crosswise of the     
original layers as the water deposited  
them1 and this produces the different   
shadings so often seen in different     
slate4 ,shale splits in line with its   
layers2 slate splits across that line4  
,let us go back a moment to our         
experiment with the lump of clay4 ,if we
 examined the mixture before submitted  
to pressure we should find that the     
oblong particles of which it was made up

 would stand in all directions1 hit or  
miss1 and if we should dry this lump of 
clay it would have no special lines of  
cleavage4 ,but the moment we have       
submitted it to a certain amount of     
pressure we find that lines of cleavage 
have been established1 and that the     
particles have been rearranged so that  
their longest dimensions are all in one 
direction1 which coincides with the     
cleavage lines4 ,if we should now take  
this same piece of clay and subject it  
to a pressure at right angles to that of
 the first experiment we should find    
that the lines of cleavage had also     
changed and that the particles had all  
been rearranged4 ,apply the principle to
 the formation of slate1 and we can     
understand how it happens that what we  
call the grain runs crosswise of the    
deposits that were made at different    
times4 ,it is not a chemical1 but purely
 a mechanical difference4 ,or1 to       
express it differently--the difference  
is a structural one produced by         

mechanical causes4  ,the origin of      
cleavage in slate has been the subject  
of much speculation and investigation1  
but like many other problems it was     
solved through the invention and        
application of the microscope4 ,thin    
layers of slate have been made1 the same
 as with limestone and chalk1 so thin   
that the light would readily pass       
through it and that an examination of   
the particles could be readily made1    
showing their arrangement under varied  
conditions4 ,science is indebted to the 
microscope for the solution of very many
 problems that for ages before had      
puzzled philosophers4     ,,chapter ,v4 
,,salt4   ,it may seem curious to the   
reader that we should care to discuss a 
subject seemingly so simple as common   
salt4 ,but it is a very usual thing for 
us to live and move in the presence of  
things that are very common to our      
everyday experience1 and yet know       
scarcely anything about them1 beyond the
 fact that they in some way serve our   

purpose4  ,salt is one of the commonest 
articles used in the preparation of our 
food4 ,it has been questioned by some   
people whether salt was a real necessity
 as an animal food1 or whether the taste
 for it is merely an acquired one4 ,all 
peoples in all ages seem to have used   
salt1 and reference to it is made in the
 earliest histories4 ,travelers tell us 
that savage tribes1 wherever they exist1
 are as much addicted to the use of salt
 as civilized people4 ,one of the early 
,african travelers1 ,mungo ,park1 tells 
us that the children of central ,africa 
will suck a piece of rock salt with the 
same avidity and seeming satisfaction as
 the ordinary civilized child will a    
lump of sugar4  ,all animals seem to    
require salt1 and it is claimed by those
 who have tried the experiment that     
after one has refrained from the use of 
salt for a certain length of time the   
craving for it becomes exceedingly      
painful4 ,it is most likely that the    
taste for salt is a natural craving4 ,in

 any event1 whether it is a natural or  
an artificial taste1 it has become an   
article of the greatest importance in   
the preparation of food1 as well as on  
account of its use in the arts4 ,salt is
 a compound of chlorine and sodium4 ,in 
chemical language it is called sodium   
chloride4 ,the symbol is ,na,cl1 which  
means that a molecule of salt is        
composed of one atom of sodium and one  
of chlorine4 ,chlorine is an exceedingly
 poisonous gas4  ,formerly the chemist  
when he wished to obtain sodium         
extracted it from common salt and       
discharged the chlorine gas into the    
air4 ,it was found that in              
establishments where the manufacture of 
sodium was conducted on a large scale   
the destructive properties of the       
chlorine discharged into the air was    
such that all vegetation was killed for 
some distance around the manufactory4   
,this came to be such a nuisance that   
the manufacturers were either compelled 
to stop business or in some way take    

care of the chlorine4 ,this is done at  
the present day by uniting the chlorine 
gas with common lime1 forming a chloride
 of lime1 which is used for bleaching   
and purifying purposes4  ,salt is found 
in great quantities as a natural product
 under the name of rock salt4 ,it is    
found in some parts of the world in     
great veins over #ajj feet in thickness4
 ,in some cases the rock salt is mined1 
when it has to be purified for          
commercial purposes4 ,the common mode of
 obtaining salt1 however1 is by pumping 
the solution from these great beds where
 it is mingled with water--salt water2  
the water is then evaporated1 and when  
it reaches a certain stage of           
evaporation the salt crystallizes and   
falls to the bottom4  ,different        
substances crystallize in different     
forms4 ,the crystallization of water    
when it freezes1 as we shall see        
hereafter1 arranges its molecules in    
such a form as to make a lump of ice of 
given dimensions lighter than the same  

dimensions of water would be4 ,salt in  
crystallizing does not follow the same  
law2 the salt crystal is in the shape of
 a cube and is denser in its crystalline
 form than in solution1 hence it is     
heavier and falls to the bottom4  ,it is
 said that there is a deposit of rock   
salt in ,galicia1 ,austria1 covering an 
area of #aj1jjj square miles4 ,there are
 also very large deposits in ,england1  
the mining of which has become a great  
industry4 ,there are also great beds of 
salt in various parts of the ,united    
,states1 notably near ,syracuse1 ,n4    
,y41 where large salt deposits were     
exposed in an old river bed formed in   
preglacial times4 ,the common mode of   
preparing salt for domestic purposes is 
by the process of evaporation from brine
 that has been pumped from salt wells4  
,the quality of the salt is determined  
largely by the temperature at the time  
of evaporating the water from it4       
,ordinary coarse salt1 such as is used  
for preserving meat or fish1 is made at 

a temperature of about #aaj degrees2    
what is known as common salt is made at 
a temperature of about #age degrees2    
while common fine or table salt is made 
at a temperature of #bbj degrees4 ,thus 
it will be seen that the process of     
granulation with reference to its       
fineness is determined by the rapidity  
of evaporation4 ,salt is one of the     
principal agents in preserving all kinds
 of meats against putrefaction4 ,it will
 also preserve wood against dry rot4    
,vessel builders make use of this fact  
to preserve the timbers used in the     
construction of the vessels4  ,salt at  
the present day is very cheap1 but at   
the beginning of the present century it 
was worth from #fj to #gj per ton4 ,the 
methods of decomposing salt to obtain   
its constituents1 which are used in     
various other compounds1 are very simple
 to-day as compared with the processes  
that prevailed in the days before the   
advent of electricity in large volume1  
such as is produced by the power of     

,niagara ,falls4 ,it is curious to note 
that a substance so useful and so       
harmless as common salt should be made  
out of two such refractory and dangerous
 elements as chlorine and sodium4 ,both 
of these elements1 standing by          
themselves1 seem to be out of harmony   
with nature1 but when combined there are
 few substances that serve a better     
purpose4  ,these great salt beds that   
are found to exist in ,england and      
,america and other parts of the world   
were undoubtedly deposited from the     
water of the ocean at some stage in the 
formation of the earth's crust4 ,it is  
well known that sea water is exceedingly
 saline2 #cjj gallons of sea water will 
produce a bushel of salt4 ,undoubtedly  
beds of salt are also formed by inland  
lakes1 such as the ,great ,salt ,lake in
 ,utah4 ,only about #b4g per cent4 of   
ocean water is salt1 while the water of 
the ,great ,salt ,lake of ,utah contains
 about #ag per cent4 ,when there is so  
much salt in water that it is called a  

saturated solution1 salt crystals will  
form and drop to the bottom1 which      
process will in time build up under a   
large body of salt water a great bed of 
rock salt4  ,the water in all rivers and
 springs contains salt to a certain     
degree1 and where it runs into a basin  
like that of a lake with no outlet1     
through the process of evaporation pure 
water is being constantly carried off1  
leaving the salt behind4 ,it is easy to 
see that if this process is kept up long
 enough the water will become in time a 
saturated solution1 when crystallization
 sets in and precipitation follows1     
accounting for the deposits of rock     
salt4     ,,air4     ,,chapter ,,vi4    
,,the ,,atmosphere4   ,meteorology is a 
science that at one time included       
astronomy1 but now it is restricted to  
the weather1 seasons1 and all phenomena 
that are manifested in the atmosphere in
 its relation to heat1 electricity1 and 
moisture1 as well as the laws that      
govern the ever-varying conditions of   

the circumambient air of our globe4 ,the
 air is made up chiefly of oxygen and   
nitrogen1 in the proportions of about   
twenty-one parts of oxygen and          
seventy-nine parts nitrogen by volume1  
and by weight about twenty-three parts  
oxygen and seventy-seven of nitrogen4   
,these gases exist in the air as free   
gases and not chemically combined4 ,the 
air is simply a mixture of these two    
gases4  ,there is a difference between a
 mixture and a compound4 ,in a mixture  
there is no chemical change in the      
molecules of the substances mixed4 ,in a
 compound there has been a rearrangement
 of the atoms1 new molecules are formed1
 and a new substance is the result4     
,about #ii-a_/b per cent4 of air is     
oxygen and nitrogen and one-half per    
cent4 is chiefly carbon dioxide4 ,carbon
 dioxide is a product of combustion1    
decay1 and animal exhalation4 ,it is    
poison to the animal1 but food for the  
vegetable4 ,however1 the proportion in  
the air is so small that its baneful    

influence upon animal life is reduced to
 a minimum4 ,the nitrogen is an inert1  
odorless gas1 and its use in the air    
seems to be to dilute it1 so that man   
and animals can breathe it4 ,if all the 
nitrogen were extracted from the air and
 only the oxygen left to breathe1 all   
animal life would be stimulated to death
 in a short time4 ,the presence of the  
nitrogen prevents too much oxygen from  
being taken into the system at once4 ,i 
suppose men and animals might have been 
so organized that they could breathe    
pure oxygen without being hurt1 but they
 were not1 for some reason1 made that   
way4  ,air contains more or less        
moisture in the form of vapor2 this     
subject1 however1 will be discussed more
 fully under the head of evaporation4   
,the air at sea-level weighs fifteen    
pounds to the square inch1 and if the   
whole envelope of air were              
homogeneous--the same in character--it  
would reach only about five miles high4 
,but as it becomes gradually rarefied as

 we ascend1 it probably extends in a    
very thin state to a height of eighty or
 ninety miles2 at least1 at that height 
we should find a more perfect vacuum    
than can be produced by artificial      
means4 ,the weight of all the air on the
 globe would be #aa-b_/c trillion pounds
 if no deduction had to be made for     
space filled by mountains and land above
 sea-level4 ,as it is1 the whole bulk   
weighs something less than the above    
figures4  ,as we have said1 the air     
envelopes the globe to a height at      
sea-level of eighty or ninety miles1    
gradually thinning out into the ether   
that fills all interstellar space4 ,we  
live and move on the bottom of a great  
ocean of air4 ,the birds fly in it just 
as the fish swim in the ocean of water4 
,both are transparent and both have     
weight4 ,water in the condensed state is
 heavier than the air and will seek the 
lowest places1 but when vaporized1 as in
 the process of evaporation1 it is      
lighter than air and floats upward4 ,in 

the vapor state it is transparent like  
steam4 ,if you study a steam jet you    
will notice that for a short distance   
after it issues from the boiler it is   
transparent1 but soon it condenses into 
cloud4  ,if we could see inside of a    
boiler in which steam had been          
generated1 all the space not occupied   
with water would seem to be vacant1     
since steam before it is condensed is as
 transparent as the air4 ,we will1      
however1 speak of this subject more     
fully under the head of evaporation and 
cloud formation4 ,it is not enough that 
we have the air in which we live and    
move1 with all of its properties1 as we 
have described3 something more is needed
 which is absolutely essential both to  
animal and vegetable life--and this     
essential is motion4 ,if the air        
remained perfectly still with no lateral
 movement or upward and downward        
currents of any kind1 we should have a  
perfectly constant condition of things  
subjected only to such gradual changes  

as the advancing and receding seasons   
would produce owing to the change in the
 angle of the sun's rays4 ,no cloud     
would ever form1 no rain would ever     
fall1 and no wind would ever blow4 ,it  
is of the highest importance not only   
that the wind shall blow1 but that      
comparatively sudden changes of         
temperature take place in the           
atmosphere1 in order that vegetation as 
well as animal life may exist upon the  
surface of the globe4 ,the only place   
where animal life could exist would be  
in the great bodies of water1 and it is 
even doubtful if water could remain     
habitable unless there were means       
provided for constant                   
circulation--motion4  ,the mobility of  
the atmosphere is such that the least   
influence that changes its balance will 
put it in motion4 ,while we can account 
in a general way for atmospheric        
movements1 there are many problems      
relating to the details that are        
unsolved4 ,we find that even the weather

 man makes mistakes in his              
prognostications2 so true is this that  
it is never safe to plan a picnic for   
to-morrow based upon the predictions of 
to-day4 ,the chief difficulty in the way
 of solving the great problems relating 
to the sudden changes in the weather and
 temperature lies in the fact that      
two-thirds or more of the earth's       
surface is covered with water2 thus     
making it impossible to establish       
stations for observation that would be  
evenly distributed all over the earth's 
surface4 ,enough is known1 however1 to  
make the study of meteorology a most    
wonderfully interesting subject4  ,we   
have already stated that air is composed
 of a mixture of oxygen and nitrogen    
chiefly1 with a small amount of carbon  
dioxide4 ,so far as the life and health 
of the animal is concerned we could get 
along without this latter substance1 but
 it seems to be a necessity in the      
growth of vegetation4 ,there are other  
things in the air which1 while they are 

unnecessary for breathing purposes1 it  
will be well for us to understand1 as   
some of them are things to be avoided   
rather than inhaled4  ,as before        
mentioned1 air contains moisture1 which 
is a very variable quantity4 ,in a cold 
day in winter it is not more than       
one-thousandth part1 while in a warm day
 in summer it may equal one-fortieth of 
the quantity of air in a given space4   
,there is also a small amount of        
ammonia1 perhaps not over               
one-sixty-millionth4 ,oxygen also exists
 in the air in very small quantities in 
another form called ozone4 ,one way to  
produce ozone is by passing an electric 
spark through air4 ,anyone who has      
operated a ,holtz machine has noticed a 
peculiar smell attending the disruptive 
discharges1 which is the odor of ozone4 
,it is what chemists call an allotropic 
form of oxygen1 just as the diamond1    
graphite1 and charcoal are all different
 forms of carbon1 and yet the chemical  
differences are scarcely traceable4 ,it 

is more stimulating to breathe than     
oxygen and is probably produced by      
lightning discharges4  ,as has been     
before stated1 the oxygen of the air is 
consumed by all processes of combustion1
 and in this we include the breathing of
 men and animals and the decay of       
vegetable matter1 as well as the more   
active combustion arising from fires4 ,a
 grown person consumes something over   
#djj gallons of oxygen per day1 and it  
is estimated that all the fires on the  
earth consume in a century as much      
oxygen as is contained in the air over  
an area of seventy miles square4 ,all of
 these processes are throwing into the  
air carbon dioxide 7carbonic acid71     
which1 however1 is offset by the power  
of vegetation to absorb it1 where the   
carbon is retained and forms a part of  
the woody fiber and pure oxygen is given
 back into the air4 ,by this process the
 normal conditions of the air are       
maintained4  ,one decimeter 7nearly #d  
inches7 square of green leaves will     

decompose in one hour seven cubic       
centimeters of carbon dioxide1 if the   
sun is shining on them2 in the shade the
 same area will absorb about three in   
the same time4  ,there is another       
substance in the form of vegetable germs
 in the air called bacteria4 ,at one    
time these were supposed to be low forms
 of animal life1 but it is now          
determined that they are the lowest     
forms of vegetable germs4 ,bacteria is  
the general or generic name for a large 
class of germs1 many of them disease    
germs4 ,by analysis of the air in       
different locations and in different    
parts of the country it has been        
determined that on the ocean and on the 
mountain tops these germs average only  
one to each cubic yard of air4 ,in the  
streets of the average city there are   
#cjjj of them to the cubic yard1 while  
in other places where there is sickness1
 as in a hospital ward1 there may be as 
many as #hj1jjj to the cubic yard4      
,these facts go to prove what has long  

been well known1 that the air of a city 
furnishes many more fruitful sources for
 disease than that of the country4 ,some
 forms of bacterial germs are not       
considered harmful1 and they probably   
perform even a useful service in the    
economy of nature4 ,within certain      
limits1 other things being equal1 the   
higher one's dwelling is located above  
the common level the purer will be the  
air4 ,this rule1 however1 has its       
limits1 as the oxygen of the air is     
heavier than the nitrogen1 so that the  
air at very great altitudes has not the 
same proportion of oxygen to nitrogen   
that it has at a lower level4 ,an       
analysis that was made some years ago of
 the air on the west shore of ,lake     
,michigan1 especially that section where
 the bluffs are high1 shows that it     
compares favorably with that of any     
other portion of the ,united ,states4   
,in view of the foregoing1 it is of the 
highest importance to the sanitary      
condition of any city1 town1 or village 

that it be not too compactly built4 ,if 
more than a certain number of people    
occupy a given area1 it is absolutely   
impossible to preserve perfect sanitary 
conditions4 ,and there ought to be a    
,state law1 especially for all suburban 
towns1 which are the homes and sleeping 
places for large numbers of business men
 who spend their days in the foul air of
 the city1 stipulating that the houses  
shall be not less than a certain        
distance apart4 ,oxygen is the great    
purifier of the blood1 and if one does  
not get enough of it he suffers even    
though he breathes no impurities4 ,the  
power to resist the effects of bad air  
is much greater when one is awake and   
active than when asleep1 and this is why
 it is more important to sleep in pure  
air than to be in it during our waking  
hours4 ,it is best1 however1 to be in   
good air all of the time4 ,by pure air  
,i do not mean pure oxygen1 but the     
right mixture of the two gases that make
 air4 ,too much of a good thing is often

 worse than not enough4 ,pure food to   
eat1 pure water to drink1 and pure air  
to breathe would soon be the financial  
ruin of a large class of doctors4       
,,chapter ,,vii4  ,,air ,,temperature4  
,the most recent definition of heat is  
that it is a mode of motion2 not        
movement of a mass of substance1 but    
movement of its ultimate particles4 ,it 
has been determined by experiment that  
the ability of any substance to absorb  
heat depends upon the number of atoms it
 contains1 rather than its bulk or its  
weight4  ,it has also been stated that  
the atmosphere at sea-level weighs about
 fifteen pounds to the square inch1     
which means that a column of air one    
inch square extending from sea-level    
upward to the extreme limit of the      
atmosphere weighs fifteen pounds4 ,the  
density of the air decreases as we      
ascend4 ,each successive layer1 as we   
ascend1 is more and more expanded1 and  
consequently has a less and less number 
of air molecules in a given space4      

,therefore the capacity of the air for  
holding heat decreases as we go higher4 
,we deduce from these facts that the    
higher we go the colder it becomes2 and 
this we find to be the case4 ,whoever   
has ascended a high mountain has had no 
difficulty in determining two things4   
,one is that the air is very much colder
 than at sea-level1 and the other that  
it is very much lighter in weight4 ,we  
find it difficult1 when we first reach  
the summit1 to take enough of oxygen    
into our lungs to carry on the natural  
operations of the bodily functions4 ,to 
overcome this difficulty1 if we remain  
at this altitude for a considerable     
time1 we shall find that our lungs have 
expanded1 so as to make up in quantity  
what is lacking in quality4  ,if a man  
lives for a long time at an altitude of 
#aj1jjj feet he will find that his lungs
 are so expanded that he experiences    
some difficulty when he comes down to   
sea-level4 ,and the reverse is true with
 one whose lungs are adapted to the     

conditions we find at sea-level1 when he
 ascends to a higher altitude4 ,there is
 a constant endeavor on the part of     
nature to adapt both animal and         
vegetable life to the surroundings4     
,while no exact formula has been        
established as to the rate of decrement 
of temperature as we ascend1 we may say 
that it decreases about one degree in   
every #cjj or #djj feet of ascent4      
,there is no exact way of arriving at   
this1 as in ascending a mountain the    
temperature will be more or less        
affected by local conditions4 ,if we go 
up in a balloon we have to depend upon  
the barometer as a means of measuring   
altitude1 which1 owing to the varying   
atmospheric conditions1 is not a        
reliable mode of measurement4 ,it is    
easily understood that a cubic foot of  
air at sea-level will contain a great   
many more atoms than a cubic foot of air
 will at the top of a high mountain2 or1
 to state it in another way1 a cubic    
foot of air at sea-level will occupy    

much more than a cubic foot of space    
#aj1jjj feet higher up4 ,suppose1 then1 
that the amount of heat held in a cubic 
foot of air at sea-level remained the   
same1 as related to the number of atoms4
 ,in its ascent we shall find that at a 
high altitude the same number of atoms  
that were held at sea-level in a cubic  
foot have been distributed over a so    
much larger space that the sensible heat
 is greatly diminished or diluted1 so to
 speak4 ,it was an old notion that heat 
would hide itself away in fluids under a
 name called by scientists latent heat4 
,this theory has been exploded1 however1
 by modern investigation4  ,if we place 
some substance that will inflame at a   
low temperature in the bottom of what is
 called a fire syringe 7which is nothing
 but a cylinder bored out smoothly1 with
 a piston head nicely fitted to it1 so  
that it will be air-tight7 and then     
suddenly condense the air in the syringe
 by shoving the plunger to the bottom1  
we can inflame the substance which has  

been placed in the bottom of the        
cylinder4 ,in this operation the heat   
that was distributed through the whole  
body of air1 that was contained in the  
cylinder before it was compressed1 is   
now condensed into a small space4 ,if we
 withdraw the plunger immediately1      
before the heat has been taken up by the
 walls of the syringe1 we shall find the
 air of the same temperature as before  
the plunger was thrust down4 ,this1     
however1 does not take into account any 
heat that was generated by friction4    
,let us further illustrate the          
phenomenon by another experiment4 ,if we
 suddenly compress a cubic foot of air  
at ordinary pressure into a cubic inch  
of space1 that cubic inch will be very  
hot because it contains all the heat    
that was distributed through the entire 
cubic foot before the compression took  
place4 ,now let it remain compressed    
until the heat has radiated from it1 as 
it soon will1 and the air becomes of the
 same temperature as the surrounding    

air4 ,what ought to happen if then we   
should suddenly allow this cubic inch of
 air to expand to its normal pressure1  
when it will occupy a cubic foot of     
space8  ,inasmuch as we allowed the heat
 to escape from it when in the condensed
 form1 when it expands it will be very  
cold1 because the heat of the cubic     
inch1 now reduced to the normal         
temperature of the surrounding air1 is  
distributed over a cubic foot of space4 
,this is precisely what takes place when
 heated air at the surface of the earth 
7which is condensed to a certain extent7
 rises to the higher regions of the     
atmosphere4 ,there is a gradual         
expansion as it ascends1 and            
consequently a gradual cooling1 because 
a given amount of heat is being         
constantly distributed over a greater   
amount of space4 ,at an altitude of     
forty-five miles it will have expanded  
about #be1jjj times1 which will bring   
the temperature down to between #bjj and
 #cjj degrees below zero4  ,when we get 

beyond the limits of the atmosphere we  
get into the region of absolute cold1   
because heat is atomic motion1 and there
 can be no atomic motion where there are
 no atoms4  ,we have now traced the     
atmosphere up to the point where it     
shades off into the ether that is       
supposed to fill all interplanetary     
space4 ,as ,dryden says3      ,there    
fields of light and liquid ether flow1  
,purg'd from the pond'rous dregs of     
earth below4  ,by interplanetary space  
we mean all space between the planets   
not occupied by sensible material4 ,it  
is the same as interatomic space1 or the
 space between atoms1 except in degree1 
as the same substance that fills        
interplanetary space also fills         
interatomic space1 so that all the atoms
 of matter float in it and are held     
together from flying off into space by  
the attraction of cohesion4 ,what this  
ether is1 has been the subject of much  
speculation among philosophers1 without1
 however1 arriving at any definite      

conclusion1 further than that it is a   
substance possessing almost infinite    
elasticity1 and whose ultimate          
particles1 if particles there be1 are so
 small that no sensible substance can be
 made sufficiently dense to resist it or
 confine it4 ,it is easy to see that a  
substance possessing such qualities     
cannot be weighed or in any way made    
appreciable to our senses4 ,but from the
 fact that radiant energy can be        
transmitted through it1 with vibrations 
amounting to billions per second1 we    
know that it must be a substance with   
elastic qualities that approach the     
infinite4 ,assuming that the ether is a 
substance1 the question arises how is it
 related to other forms of substance8   
,this is a question more easily asked   
than answered4 ,the longer one dwells   
upon the subject1 however1 the more one 
is impressed with the thought that after
 all the ether may be the one element   
out of which all other elements come4   
,chemistry tells us that there are      

between sixty and seventy ultimate      
elements4 ,this is true at least as a   
basis for chemical science4 ,chemical   
analysis has never been able to make    
gold anything but gold1 or oxygen       
anything but oxygen1 and so on through  
the whole catalogue of elements4 ,it may
 be1 however1 that the play of forces   
under and beyond those that seem to be  
active in all chemical processes and    
relations1 are able to produce certain  
affections of the ether1 the result of  
which in the one case is an atom of gold
 and in the other an atom of oxygen1    
etc41 to the end of the list4 ,in this  
case all of the so-called elements may  
have their origin in one fundamental    
element that we call the ether4 ,i am   
aware that we are wading in deep water  
here1 but sometimes we love to get into 
deep water just to try our swimming     
powers4 ,the above is a suggestion of a 
theory called the vortex theory1 that is
 taking root in the minds of many       
philosophers to-day1 and yet there is   

almost nothing of known facts to base   
such a theory upon1 and nearly all we   
can say about it is that it seems       
plausible1 when viewed through the eye  
of imagination4  ,we do know that       
substances1 such as fluids or gases1    
assume very different qualities when put
 into different rates of motion4 ,a     
straw has been known to penetrate the   
body of a tree endwise by the extreme   
velocity imparted to it when carried in 
the vortex of a tornado4 ,instances of  
the terrific solid power of substances  
that are mobile when at rest are often  
exhibited during the progress of a      
tornado1 especially when confined in    
very narrow limits4 ,sometimes a tornado
 cloud will form a hanging cone1 running
 down to a sharp point at the lower end1
 which lower end may drag on the ground1
 or it may float a little distance above
 the ground1 but more frequently it     
moves forward with a bounding motion1   
now touching the earth and now rising in
 the air4 ,this cone is revolving at a  

terrific speed4 ,the substance revolving
 is chiefly air1 carrying other light   
substances that it has gathered up from 
the ground4 ,if it comes in contact with
 a tree or building it cuts its way     
through as though it were a buzzsaw     
revolving at a high rate of speed4 ,this
 is not simply the force of wind1 but a 
kind of solidity given to the fluent air
 by its whirling motion4  ,i remember a 
case in ,iowa1 where one of these       
revolving cones passed through a        
barnyard1 striking the corner of the    
barn1 cutting it off as smoothly as     
though done with some sharp-edged tool1 
but it in no other way affected the rest
 of the building4 ,one would suppose    
that the centrifugal force developed in 
this whirling motion would cause the    
cone to fly apart1 and why it does not  
no one certainly knows4 ,but we are     
obliged to accept the fact4  ,these     
cases are cited to show that motion     
gives rigidity to substances that in the
 quiescent state are mobile or easily   

moved1 like the straw or the air4 ,if we
 should assume that there are           
infinitesimal vortices or whirling rings
 in the ether1 of such rapidity as to   
give it different degrees of rigidity1  
we can get a glimmering idea of how an  
atom of matter may be formed from ether4
  ,referring to the rigidity which      
motion gives to ordinary matter1 it is  
well known that when two vessels at sea 
collide the one having the higher speed 
is not so liable to injury as the one   
with the lower4 ,the reader will perhaps
 remember a circumstance said to have   
occurred a few years ago on the ,lake   
,shore ,railroad1 between ,buffalo and  
,cleveland4 ,the limited express was    
going west1 and while rounding a curve  
the engineer suddenly came in sight of a
 wrecked freight train1 a part of which 
was lying on the track where the express
 train had to pass4 ,the engineer saw   
that he was too near the wreck to stop  
his train and that the only way to save 
his own train and the lives of his      

passengers would be to cut through the  
wreck4 ,he pulled out the throttle and  
put on a full head of steam1 and when   
the train struck the wreck it was going 
at such a high rate of speed that it cut
 through without seriously damaging the 
train and without harm to the           
passengers4  ,there are other heroes    
beside those who lead armies in battle4 
,,chapter ,,viii4                       
,,cloud-,,formation--,,evaporation4     
,water exists in different forms        
without1 however1 undergoing any        
chemical change4 ,it is when condensed  
into the fluid state that we call it    
water1 and then it is heavier than the  
atmospheric air and therefore seeks the 
low places upon the earth's surface1 the
 lowest of which is the bed of the      
ocean4 ,wherever there is water or      
moisture on the face of the globe there 
is a process going on at the surface    
called evaporation4 ,this process is    
much more rapid under the action of heat
 than when it is colder4 ,in other      

words1 as the heat increases evaporation
 increases within certain limits and    
bears some sort of a ratio to it4       
,evaporation is not confined to water1  
but as our subject has to deal with     
atmospheric phenomena we will speak of  
it only in its relation to aqueous      
moisture4  ,the heat that is imparted to
 the earth's surface by the rays of the 
sun is able to separate water into      
minute particles1 which1 when so        
separated1 form what is called vapor1   
which is transparent1 as well as much   
lighter than the air at the surface of  
the earth4 ,being lighter than the air1 
it rises when disengaged and floats to  
the upper regions of the atmosphere4    
,the atmosphere will contain a certain  
amount of these transparent globules of 
moisture in the spaces between its own  
molecules4 ,if the air is warm the      
molecules will be farther apart and it  
will contain more moisture than when it 
is cold4  ,the process of evaporation is
 one of the most important in the       

catalogue of nature's dynamics4 ,without
 it there would be no verdure on the    
hills1 no trees on the plains1 no fields
 of waving grain1 and no animal life    
upon the land surface of the globe4     
,evaporation is nature's method of      
irrigation1 and the system is           
inaugurated on a grand scale1 so that   
there are but few neglected spots upon  
the face of the earth which moisture1   
carried up from the great reservoirs of 
water1 does not reach4 ,the rate of     
evaporation1 other things being equal1  
depends upon the extent of surface2     
therefore a smooth surface like that of 
the lake or ocean will not send up as   
much vapor from a given area in square  
miles as an equal area of land will do1 
when it is saturated with moisture1 for 
the reason that there is a much larger  
evaporating surface on a square mile of 
land1 owing to its inequalities1 than   
upon an equal area of smooth water4 ,of 
course1 if the earth is dry there can be
 but little evaporation4 ,one of the    

effects of evaporation is to withdraw   
heat1 and so to produce cold in the     
substance from which the evaporation    
takes place4  ,if we put water into a   
vial and drop regularly upon it some    
fluid that evaporates readily it will   
extract the heat from the vial and the  
water in it to such an extent that in a 
short time the water will be frozen4 ,in
 hot countries ice is manufactured on a 
large scale upon the principle that we  
have just described4 ,water is put into 
shallow basins1 excavated in the earth1 
over which is placed some substance like
 straw that readily radiates heat1 and  
on the straw are placed porous bricks1  
that are kept wet1 thus furnishing a    
very large evaporating surface4 ,in this
 way the process of evaporation is      
carried on very rapidly and the heat is 
extracted from the water to such an     
extent that it freezes1 often forming   
ice in one night over an inch in        
thickness1 and this in the hottest      
climates on the globe4 ,evaporation     

cannot go on in places where the air is 
already saturated with moisture4 ,when  
the air is dry evaporation is very      
rapid1 but as it becomes more and more  
filled with moisture the evaporation is 
checked to the same degree4 ,this fact  
accounts for the difference of bodily   
comfort that we experience at different 
times in the year when the temperature  
is the same4 ,sometimes we are very     
uncomfortable although the temperature  
is not above #ge degrees ,fahrenheit1   
more so even than we are at other times 
when the temperature is ten or fifteen  
degrees higher4 ,if the air is saturated
 with moisture1 even though the         
temperature is not above #gj or #ge     
degrees1 the perspiration is not readily
 evaporated from the surface of the     
body4 ,if the air is dry the temperature
 may be much higher and we be much more 
comfortable1 because evaporation goes on
 rapidly1 which keeps the body not only 
dry1 but cool4 ,i remember passing      
through a desert in ,arizona where there

 was scarcely a green thing in sight in 
any direction1 and the temperature was  
said to be #adj degrees4 ,i did not     
suffer as much as ,i often have done in 
the ,east with the thermometer at #hj or
 #ij degrees1 and there was very little 
show of sensible perspiration2 it was   
going on rapidly1 however1 but was being
 absorbed by the dry air4 ,this goes to 
show that temperature is not the only   
factor to be considered when we are     
making an estimate of the good or bad   
qualities of a climate4  ,evaporation is
 carried on much more rapidly when the  
wind blows than at other times1 for the 
reason that the moisture is carried off 
laterally as fast as it is formed1 all  
resistance to its escape into the upper 
air being removed4 ,if the air is       
charged to saturation with moisture at a
 certain temperature1 it will remain so1
 and evaporation stops so long as the   
temperature remains unchanged4 ,if its  
temperature rises the process of        
evaporation can start up1 because the   

capacity of the air for holding moisture
 has been increased4 ,but if a          
temperature is perceptibly lowered      
another phenomenon will manifest itself4
  ,in the uncondensed state vaporized   
moisture is quite transparent1 so that  
we are able to see through it as we do  
through a pane of glass4 ,if1 however1  
the body of air that is saturated with  
this invisible moisture becomes suddenly
 chilled1 the moisture condenses into   
cloud or mist4  ,if we watch a passing  
railroad train we shall notice a mass of
 fleecy white mist floating away from   
the smokestack1 assuming the billowy    
forms of some of the clouds in summer4  
,this cloud is produced by the sudden   
condensation of steam1 which was        
transparent before it came in contact   
with the cold1 outside air1 the effect  
being much more pronounced in cold than 
in warm weather4 ,we may liken these    
floating globules of mist to the dust of
 the earth which floats in the air1 and 
it has not been inaptly called          

water-dust4 ,anyone who has seen an     
atomizer used or has stood at the foot  
of a great waterfall1 like ,niagara1 has
 seen the fluid so finely divided that  
it will float in the air1 instead of    
falling to the ground4 ,what takes place
 is that a number of these transparent  
atoms of moisture that are released in  
the process of evaporation coalesce into
 one small drop or particle of water1   
and they will continue to float in the  
air as mist or cloud until a sufficient 
number have combined into one solid mass
 to render that mass heavier than the   
air1 when it falls in the form of rain4 
,if we live in a region--and there are  
such on the face of the earth--where    
there is very little evaporation and    
consequently very little moisture in the
 air1 there is rarely ever a cloud seen 
nor is there any rainfall1 for the      
reason that there is no material        
existing out of which to form clouds1   
and the clouds precede the rain4 ,hence1
 all the artificial attempts to produce 

rain in these arid regions have been    
futile4 ,if a body of warm air1 when    
saturated with invisible moisture1 is   
suddenly chilled by coming in contact   
with a cold wave1 it is squeezed like a 
sponge1 so to speak1 and the invisible  
particles become visible because a      
number of them have coalesced as one    
particle2 the particles gather in a     
large mass1 and we have the phenomenon  
of cloud formation4  ,clouds more       
generally form in the upper regions of  
the atmosphere because it is normally   
colder in the higher regions4 ,in some  
cases clouds float very high in the air 
and in others very low4 ,this is due to 
two causes3  ,if we should send up a    
balloon containing air rarefied to a    
certain extent it would continue to     
ascend only until it reached a point    
where the outside air and that contained
 in the balloon are of the same density4
 ,if we should send up this same balloon
 on different days with the same        
rarefaction of internal air we should   

find that on some days it would float   
higher than others1 because the density 
of the air is constantly fluctuating1 as
 is indicated by the rise and fall of   
the barometer4 ,now let us consider the 
balloon as a globule of moisture of a   
definite weight1 and this globule only  
one of an aggregation of globules       
sufficient to form a cloud4 ,we can     
readily see from what has gone before   
that a cloud thus formed1 having a      
definite density and weight1 would float
 higher some days than others4          
,assuming again that the density of the 
air remains the same from day to day1   
the clouds will still float high or low 
in the atmosphere from another cause4   
,let us go back to our illustration of  
the balloon4 ,if we have a fixed        
condition of atmosphere1 external to the
 balloon1 and vary the conditions       
internally1 which means varying its     
weight1 the balloon will float higher or
 lower as the internal conditions are   
varied4 ,now apply this principle to the

 moisture globules of which a cloud is  
formed and we can understand why a cloud
 will float high or low from the two    
causes that we have described4 ,clouds  
are of different color and density1 and 
this is due to the differences of the   
make-up of the moisture globules of     
which the clouds are formed4 ,if these  
globules are in an advanced stage of    
condensation the cloud is darker and    
more opaque4 ,in earlier conditions of  
condensation the cloud will have a      
bright look1 which shows that it        
reflects most of the light1 whereas in  
the case of the dark cloud the light is 
largely absorbed4  ,there is a sort of  
notion prevailing that clouds come up   
from the horizon1 and in many cases they
 do1 but they may form directly over our
 heads4 ,there always has to be a       
beginning1 and that occurs wherever the 
conditions are most favorable for       
condensation of vapor4 ,if the earth is 
wet and the sun is hot the evaporation  
may be very rapid as well as the ascent 

of the invisible moisture1 which carries
 with it the air1 which in turn expands 
the higher it rises1 thus producing     
cold4 ,this1 taken with the normal cold 
that exists in the higher regions1 may  
be sufficient to produce a sudden       
condensation of this ascending vapor1   
which is all that is necessary to form a
 cloud4  ,the inquiry may arise1 ,why is
 the moisture condensed1 almost always1 
in the upper regions of the air1 where  
it is rare8 ,because the more rare and  
therefore expanded it is1 the more      
moisture it will hold4 ,this1 taken with
 the fact that cold currents are        
encountered high up1 sufficiently       
answers the question4  ,it is           
interesting to know that the processes  
of nature are interdependent4 ,it is not
 enough that we have the evaporation of 
moisture that will ascend into the      
higher regions of the air and there be  
condensed into cloud and possibly rain1 
but we must have the means for          
distributing these conditions over a    

large area1 and for this purpose we have
 the phenomenon of wind4 ,why the winds 
blow can be accounted for to a certain  
extent1--we might say to a large        
extent1--but there yet remain many      
unsolved problems relating to wind and  
weather4 ,of the phenomena of wind we   
will speak more fully in a future       
chapter4     ,,chapter ,,ix4  ,,cloud   
,,formation--,,continued4   ,as water in
 its condensed state is #hae times      
heavier than air1 the question naturally
 comes to one why it does not           
immediately fall to the earth when it   
condenses4 ,there are at least two and  
probably more stages of condensation4   
,investigators into the phenomenon of   
cloud formation claim to have           
ascertained that the first effect of    
condensation is to form little globes of
 moisture that are hollow1 like a       
bubble1 with very thin walls4 ,everyone 
has recognized the ease with which a    
soap bubble will float in the air1 and  
yet it is simply a film of moisture4    

,these little balloons1 so to speak1 are
 called spherules4 ,it is undoubtedly   
the case that mingled with these little 
bubbles of moisture there are fine      
particles of solid water hanging on and 
carried along with them4 ,undoubtedly   
this is true2 at least just before the  
final act of condensation takes place2  
and when the little hollow spherules    
collapse they are gathered together in  
drops of water larger or smaller        
according to the rapidity of            
condensation4 ,there is probably another
 power at work to prevent the too ready 
precipitation of moisture when          
condensed1 and that is the wind4 ,a     
cloud never stands still1 although in   
some cases it may appear to do so4 ,if  
we take a stone in our hand and allow it
 to drop without applying any force to  
it1 it will fall directly to the ground4
 ,but if we give it an impetus in a     
horizontal direction it will travel some
 distance before striking the ground4   
,if we could give the same impetus to a 

body as light as a globule of water-dust
 it would probably travel indefinitely  
without falling4 ,dust that would settle
 directly to the ground from an         
elevation in still air would travel     
thousands of miles without falling1     
before a wind having any considerable   
velocity4  ,suppose the sun to be       
shining with intense heat upon a certain
 area of the earth's surface and the    
conditions to be right for very rapid   
evaporation of moisture4 ,the air which 
is heated close to the ground1 being    
expanded1 will rise1 together with the  
invisible particles of moisture1 and    
there will be a column of moisture-laden
 air continually ascending until it     
reaches a point in the upper atmosphere 
where it is condensed into a cloud that 
takes on the billowy form which in      
summer time we call a thunder cloud1 but
 which in the science of meteorology is 
called cumulus1 or heap-cloud4 ,if there
 were no air currents this billowy cloud
 would stand as the capping of an       

invisible pillar of ascending vapor1 but
 as it is never the case that air is not
 moving at some velocity in the upper   
regions1 it floats away as rapidly as it
 is formed4 ,this peculiar kind of cloud
 is formed in the mid-regions of the    
atmosphere1 and it is a summer cloud as 
well as a land cloud4 ,of course1 it may
 float off over the ocean and maintain  
its peculiar shape for a certain        
distance1 but it is rare that such a    
cloud would ever be seen in mid-ocean or
 in midwinter4 ,as the warm season      
advances in summer1 and evaporation from
 the earth is less than the rainfall1   
there is less and less moisture in the  
air1 when1 of course1 the conditions for
 cloud formation1 especially inland1 are
 not so favorable as in the early spring
 or summer4 ,frequently there comes a   
time when we have a long season of dry1 
settled weather4 ,probably during most  
of the days clouds will form and we     
think it is going to rain1 but before   
night they have vanished1 and the same  

thing is repeated the next day and the  
next1 perhaps for weeks at a time4  ,the
 explanation is this3 ,we have already  
said that so long as the air remains in 
a uniform condition as to temperature it
 will absorb moisture in a transparent  
state until it is filled to the measure 
of its capacity at a given temperature4 
,if there were no change of temperature1
 it would not condense into cloud4      
,clouds may be absorbed into the        
atmosphere--or evaporated--and become   
invisible2 and this process is going on 
to a greater or less degree continually4
 ,if we watch the steam as it escapes   
from a steam boiler1 the first effect is
 condensation into cloud1 but as it     
floats away it gradually melts and is   
absorbed into the atmosphere as         
invisible vapor4 ,this is especially    
true on a warm day2 the same process    
takes place in the air that is going on 
at the level of a body of water or at   
the surface of moist earth4  ,as before 
stated1 condensation always takes place 

when a body of moisture-laden air comes 
in contact with cold4 ,when the steam   
escapes from a boiler1 even on the      
hottest day1 it is hotter than the      
surrounding air2 the first effect is    
condensation1 and then evaporation takes
 place the same as it would at the      
surface of the earth when the condensed 
particles of moisture are separated into
 the invisible atoms that accompany     
evaporation4  ,in settled1 dry weather  
as the sun approaches the zenith1 the   
earth becomes intensely heated1 and     
there is an ascending column of air     
partly laden with moisture2 but not to  
the same extent as earlier in the       
season4 ,condensation takes place and   
clouds are formed1 but as there is not  
sufficient moisture to carry them to the
 point of a further condensation1--which
 would result in precipitation1--as the 
sun lowers in the west and the heated   
air becomes more evenly distributed this
 condensed vapor is reabsorbed into the 
air as invisible moisture by a process  

allied to that of evaporation4 ,this    
condition of things would extend to a   
much longer period than it does in our  
latitude if it were not for the gradual 
changing of the seasons1 which finally  
destroys the balance in the dynamics of 
cloud-land and allows the cold--that has
 been held back for the time--in the    
great northern zone to get the upper    
hand4 ,then we have what is termed in   
common parlance a change in the weather1
 or1 more properly in this case1 a      
change in the season4  ,we have already 
spoken of the cloud called cumulus      
7which means heap7 and of its           
performance during the dry season of    
summer4 ,there is another form of cloud 
that is seen at this season of the year 
called cirrus 7a curl74 ,it takes the   
form of a curl at its ends4 ,this cloud 
usually has a threaded shape and        
sometimes takes the form of a feather1  
and frequently forms are seen that      
remind you of frost pictures on a window
 pane4 ,these clouds float very high in 

the atmosphere1 away above the tops of  
the highest mountains1 from six to eight
 miles above the level of the sea4 ,they
 are formed only at a season of the year
 when the atmospheric conditions are    
most uniform4 ,at certain times of the  
day and night the moisture will rise to 
this height before it condenses and when
 it does condense it immediately        
freezes1 which makes it take on these   
peculiar forms that would no doubt      
conform very closely to the frost       
pictures on the window pane if it were  
not for the disturbing influences of air
 currents at this altitude4 ,the fact   
that they are ice or frost clouds       
instead of water clouds gives them that 
peculiar whiteness and brightness of    
appearance4 ,if ordinary clouds are     
water-dust these high clouds may be     
called ice-dust4 ,sometimes we see them 
lying in bands or threads running across
 the sky in the direction that the wind 
blows4 ,their form is undoubtedly a     
resultant of the struggle between the   

air currents and the tendency of        
crystallized water to arrange itself in 
certain definite lines or forms4 ,this  
cloud may be said to be one extreme1    
having its home in the highest regions  
of cloud-land1 while the cumulus1 or    
thunder cloud1 is the other extreme and 
occupies the lower or mid regions of the
 air4  ,there is a still lower cloud of 
course1 as ordinary fog is nothing more 
than cloud1 which under certain         
conditions lies on the surface of the   
ocean or dry land4 ,fogs prevail when   
the barometer is low4 ,as soon as it    
rises from the source of evaporation the
 moisture condenses almost to the point 
of precipitation4 ,there is not enough  
buoyancy in its globules when the air is
 light1 as it is when we have a low     
barometer1 to cause the fog to float    
into the higher regions of the          
atmosphere4  ,the high clouds1 which are
 called cirrus1 under certain conditions
 drop down to where they begin to melt  
into ordinary moisture globules1 and    

while this process is going on we have a
 combined cloud effect which is called  
cirro-stratus4 ,this form of cloud may  
be recognized1 when looking off toward  
the horizon1 by its being formed into   
long straight bands4 ,it is sometimes   
called thread-cloud4 ,as it further     
descends it takes on a different form   
called the cirro-cumulus1 or curl-heap4 
,this is just the opposite in its       
appearance to the cirro-stratus1 as it  
is broken up into flocks of little      
clouds separated from each other and in 
the act of changing to the form of the  
cumulus1 or billowy form of cloud2 and  
this latter takes place when it drops to
 a still lower stratum of warmer air and
 is there called the cumulo-stratus1    
which is the form of cloud we most often
 see in the season of thunderstorms4    
,the lower edge of the cloud is         
straight1 parallel with the horizon1    
while the upper part is made up of great
 billowy masses1 having high lights upon
 their well defined projections and     

blending into darker shades caused by   
the shadows in the valleys between the  
mountains of cloud4  ,the rain cloud is 
called the nimbus1 and may be said to be
 the extension of a cumulo-stratus4     
,when it reaches this condition it is   
condensed to a point where the vesicular
 globules collapse and a number of them 
run together1 forming a solid drop of   
water1 and here it begins to fall4 ,it  
may be very small at first1 but in its  
fall other condensed globules will      
adhere to it and if the conditions are  
right1 sometimes the rain drops will    
have the diameter of a quarter of an    
inch by the time they reach the earth4  
,under other conditions1 such as we have
 sometimes during dry weather1 the rain 
drops will start to fall1 but instead of
 growing larger1 they grow smaller by   
absorption into the thirsty air1 and    
will not be allowed to reach the earth4 
,often there are showers of rain in the 
air that fall to a certain distance and 
are taken up1 as in the process of      

evaporation1 to again be formed into    
cloud1 without ever having touched the  
earth4  ,thus it will be seen that      
clouds assume various forms under       
various conditions of atmosphere1 as it 
is related to moisture1 temperature1 and
 density4 ,clouds sometimes appear to be
 stationary when they are only          
continually forming on one side and     
continually being absorbed into         
invisible moisture on the other4 ,i     
remember seeing some wonderfully        
beautiful cloud effects in the regions  
of the ,alps4 ,almost every day in      
summer there appears above the peak of  
,mount ,blanc a beautifully formed cloud
 cap standing some distance above it and
 hollowed out underneath like an        
inverted cup4 ,although this cloud      
appears to be stationary1 it is         
undergoing a rapid change2 the moisture 
rises from the snow-capped peak as      
invisible vapor to a certain distance1  
where it is condensed into a cloud of   
wonderful brilliancy4 ,as the cloud     

globules float upward they are absorbed 
into the atmosphere again1 as invisible 
moisture at the upper limit of the      
cloud4 ,if the wind happens to be       
blowing1 another phenomenon takes place1
 giving the appearance somewhat of a    
volcano4 ,it is blown off from the peak 
in the direction of the wind1 but within
 a short distance it strikes a warmer   
stratum of air1 where it is absorbed and
 assumes the transparent condition4  ,if
 we ascend a high mountain1 we get some 
idea of the altitude of the various     
forms of cloud4 ,a thunderstorm may be  
in progress far below us1 while the sun 
may be shining from a clear sky above1  
with perhaps the exception of the frost 
clouds that we have referred to floating
 high above the mountain tops4  ,we have
 now described in a general way how     
clouds are formed1 how they are         
condensed into rain1 and how moisture is
 distributed over large areas by these  
rain clouds being borne on the wings of 
the wind2 and now you ask1 ,whence the  

wind8 ,in our next and following        
chapters we will try to answer this     
question4     ,,chapter ,x4             
,,wind--,,why ,,it ,,blows4   ,we have  
said that globules of moisture1 released
 by the action of the sun's rays in the 
process of evaporation1 tend to rise    
because they are lighter than the air4  
,right here let it be said that all     
material substances have weight2 even   
hydrogen1 the lightest known gas1 has   
weight1 and is attracted by gravitation4
 ,if there were no air or other gaseous 
substances on the face of the earth     
except hydrogen1 it would be attracted  
to and envelop the earth the same as the
 air now does4 ,carbon dioxide is a gas 
that is heavier than the air4 ,if we    
take a vessel filled with this gas and  
pour it into another vessel it will sink
 to the bottom and displace the air     
contained in it until the air is all    
driven out4 ,if we fill a jar with water
 up to a certain height and then pour a 
pint of shot into it the water will be  

caused to rise in the vessel because it 
has been displaced at the bottom by the 
heavier material4 ,now if we remove the 
shot the water will recede to the level 
maintained before the shot was put in4  
,on the contrary1 if we should pour an  
equal bulk of cork or pith balls into   
the jar the water would not be          
displaced1 because the balls are lighter
 than the water and would lie on top of 
it2 if1 however1 the water is removed   
from the jar1 the cork will immediately 
go to the bottom of the jar1 because the
 cork is heavier than the air which has 
taken the place of the water4 ,we wish  
to impress upon the mind of the reader  
the fact1 that all substances of a      
fluidic nature1 whether in the fluid or 
gaseous state1 have weight1 and obey the
 laws of gravitation1 and the heavier   
portions will always seek the lower     
levels1 and in doing this will displace 
the lighter portions1 causing them to   
rise4 ,there is no tendency in any      
substance to rise of itself1 but the    

lighter substance rises because it is   
forced to do so by the heavier1 which   
displaces it4 ,this law lies at the     
bottom of all of the phenomena of air   
currents4  ,if we are at certain points 
on the seashore in the summer time we   
may notice that about #i o'clock in the 
morning a breeze will spring up from the
 ocean and blow toward the land2 this   
will increase in intensity until about  
#b o'clock in the afternoon1 when it has
 reached its maximum velocity1 and from 
this time it gradually diminishes1 until
 in the evening there will be a season  
of calm1 the same as there was in the   
early morning4 ,the explanation of this 
peculiar action of the air is found in  
the fact that during the day the land is
 heated much more rapidly on its surface
 than the water is4  ,the radiant energy
 from the sun is suddenly arrested at   
the surface of the earth1 which is      
heated to only a very shallow depth1    
while in the water it is different2     
being transparent it is penetrated by   

the radiant energy to a much greater    
depth and does not suddenly arrest it1  
as is the case on land4 ,as the sun     
rises and the rays strike in a more and 
more vertical direction the earth       
becomes rapidly and intensely heated at 
its surface1 and this in turn heats the 
stratum of air next above it1 which is  
pressing on it with a force of fifteen  
pounds to the square inch at sea-level4 
,when air is heated it expands1 and as  
it expands it grows lighter4 ,the       
stratum lying upon the earth as soon as 
it becomes heated moves upward and its  
place is occupied by the heavier1 cooler
 air that flows in from the sides4 ,we  
can now see that if there is a strong   
ascending current of air on the land    
near the ocean the cooler air from the  
surface of the ocean will flow in to    
take the place of the warmer and lighter
 air that is driven upward1 really by   
the force of gravity which causes the   
heavier fluid to keep the lowest level4 
,as the earth grows hotter this movement

 is more and more rapid1 which causes   
the flow of colder air to be quickened1 
and hence the increasing force of the   
wind as the sun mounts higher in the    
heavens4 ,but when it has passed the    
point of maximum heating intensity and  
the earth begins to cool by radiation1  
the movements of air currents begin to  
slow up1 until along in the evening a   
point is reached where the surface of   
the earth and that of the ocean are of  
equal temperature1 and there is no      
longer any cause for change of position 
in the air4  ,the earth heats up        
quickly1 and it also cools quickly1     
especially if there is green grass and  
vegetation4 ,while they are poor        
conductors of heat1 they are excellent  
radiators1 so that when the sun's rays  
are no longer active the earth cools    
down rapidly and soon passes the point  
where there is an equilibrium between   
the land and water4 ,the water possesses
 the opposite quality4 ,it is slow to   
become heated1 because of a much larger 

mass that is affected1 and is equally   
slow to give up the heat4 ,and the      
consequence is that after the sun has   
set1 the land cools so much faster than 
the water that we soon have the opposite
 condition1 and the sea is warmer than  
the land1 which makes the air at that   
point lighter1 and which in turn causes 
the denser or colder air from the land  
to flow toward the ocean1 and displace  
the lighter air and force it upward2    
hence we have a land instead of a sea   
breeze4 ,so that the normal condition in
 summer is that of a breeze from the    
ocean toward the land during part of the
 day and a corresponding breeze from the
 land to the ocean during part of the   
night1 with a period of no wind during  
the morning and evening of each day4    
,the forces that work to produce all the
 varying phenomena of air currents on   
different portions of the earth are     
difficult to explain1 as there are so   
many local conditions of heat and cold1 
and these are modified by the advancing 

and receding seasons4 ,the unequal      
distribution of land and water upon the 
earth's surface2 the readiness with     
which some portions absorb and radiate  
heat as compared with others2 the tall  
ranges of mountains1 many of them       
snow-capped2 the lowlands adjacent to   
them that become intensely heated under 
the sun's rays2 the diversity of        
coastline and the fact that there is a  
zone of continually heated earth and    
water in the tropical regions--all these
 conditions1 coupled with the fact that 
the earth rotates on its axis once in   
twenty-four hours1 are certainly        
sufficient to account for all the       
complicated phenomena of aerial changes 
on the various portions of the earth's  
surface4  ,the trade winds are so called
 because they blow in a certain definite
 direction during certain seasons of the
 year1 and can be reckoned upon for the 
use of commerce4 ,if you trace the line 
of the equator you will notice that for 
more than three-quarters of the distance

 it passes through the water4 ,the      
water1 as we have explained in the last 
chapter1 becomes gradually heated to a  
considerable depth1 and when once       
saturated with heat is slow to give it  
up4 ,it can easily be seen that there   
will be a zone extending each way from  
the equator for a certain distance that 
will become more intensely heated than  
any other parts of the earth1 with the  
exception of certain circumscribed      
portions of the land4 ,the result is    
that this heated equatorial zone is     
constantly sending up warm air caused by
 the inrush of colder air1 which is     
heavier than the air at the equator1    
expanded by the heat4 ,the warm air at  
the equator is forced up into the higher
 regions of the atmosphere1 and here it 
overflows each way1 north and south1    
causing a current of air in the upper   
regions counter to that of the lower4   
,as it travels north and south it       
gradually drops as it becomes cooler1   
and finally at some point north and     

south its course is changed and it flows
 in again toward the equator4 ,as a     
matter of fact1 the trade winds do not  
flow apparently from the north and south
 directly toward the equator1 but in an 
oblique direction4 ,on the north side of
 the equator we have a northeasterly    
wind1 and a southeasterly wind on the   
south side4 ,this is caused by the      
rotation of the earth from west to east4
 ,the direction of the trade wind1      
however1 is more apparent than real4    
,the earth in its diurnal revolutions   
travels at the rate of a little more    
than #ajjj miles an hour at the equator4
 ,but if we should travel northward to  
within four miles1 say1 of the north    
pole1 the surface point would be moving 
at the rate of only about a mile an     
hour4 ,at some point equidistant between
 the north pole and the equator the     
surface of the earth will be moving at a
 rate1 say1 of #ejj miles an hour4 ,if  
we could fire a projectile from this    
point that would have a carrying power  

to take it to the equator some time     
after the projectile was fired1 although
 it would fly in a perfectly direct     
line1 it would appear to anyone at the  
equator who observed its approach to be 
moving from a northeasterly direction4  
,the reason is that the earth is        
traveling twice as fast at the equator  
as it is at the point whence the        
projectile is fired4 ,therefore it will 
overshoot1 so to speak1 at the equator1 
and not be dragged around by the        
increased motion we find there4  ,to    
make this still plainer1 suppose the    
earth to be standing still and a        
projectile be fired directly across from
 the north pole in the direction of the 
lines of longitude and required one hour
 to reach the equator1 the projectile   
would appear to anyone standing at the  
equator to come directly from the north4
 ,if1 however1 the earth is revolving at
 the rate of #ajjj miles an hour at the 
equator to the eastward1 and the        
projectile was fired from the pole1     

where there is practically no motion1 in
 the same direction along the           
longitudinal lines as before1 the       
observer would have to be in a position 
on the equator #ajjj miles west of this 
longitudinal line in order to see the   
projectile when it arrived2 therefore   
the apparent movement of the projectile 
would not be along the line at the      
instant that it was fired1 but along a  
line that would cross the equator at a  
point #ajjj miles west4 ,when a         
southward impulse is given to the air it
 follows1 to some extent1 the same law1 
so that to one standing on the equator  
the northern trade wind will blow from  
the northeast and the southern trade    
wind from the southeast4  ,owing to the 
fact that the air rises in the heated   
zone there is always a region of calms  
at this point where there is no wind and
 no rain4 ,there are two other regions  
of calms in the ocean1 one at the north 
at the tropic of ,cancer and another at 
the south near the tropic of ,capricorn4

 ,as has been stated1 there are currents
 flowing back in the upper regions at   
the equator north and south1 and these  
are called the upper trades--the lower  
currents being called the lower trades4 
,these upper trades gradually fall till 
they reach the tropic of ,cancer on the 
north1 where the lower part of the      
current stops and bends back toward the 
equator1 now becoming a part of the     
lower trade wind4 ,this causes a calm at
 that point where it turns4 ,the upper  
parts of this current continue on1 in a 
northerly and southerly direction1 on   
the surface until they meet with the    
cold air of the north and south polar   
regions1 where there is a conflict of   
the elements--as there always is when   
cold and warm currents meet4  ,the only 
point where the trade wind has free play
 is in the ,south ,indian ,ocean1 and   
this is called the heart of the trades4 
,if the whole globe were covered with   
water there would be a more constant    
condition of temperature2 but owing to  

the great difference between the land   
and water1 both as to altitude and the  
ability to absorb and radiate heat1 we  
have all of these varied and complicated
 conditions of wind and weather4 ,the   
trade winds shift from north to south   
and vice versa with the advancing and   
receding seasons1 due to the fact that  
the earth has a compound motion4 ,it not
 only revolves on its axis once in      
twenty-four hours1 but it rocks back and
 forth once a year1 which is gradually  
changing the direction of its axis2 and 
in addition to these motions it is      
traveling around the sun as well4       
,,chapter ,,xi4  ,,wind--,,continued4   
,in our last chapter we discussed the   
winds that prevail in the regions of the
 tropics called trade winds1 because    
they follow a direct course through the 
year1 with the exceptions noted in      
regard to their shifting to the north or
 south with the changing seasons2 we    
also described the phenomena of land and
 sea breezes1 which during certain      

seasons of the year reverse their       
direction twice daily4 ,we will now     
describe another kind of wind1 called   
monsoons1 that prevail in ,india4       
,india lies directly north of the great 
,indian ,ocean1 and the lower part of it
 comes within the tropical belt lying   
south of the ,tropic of ,cancer4 ,during
 the summer season here the earth stores
 more heat during the day than it       
radiates or loses during the night4     
,this causes the wind to blow in a      
northerly direction from the sea both   
day and night for six months each year1 
from ,april to ,october4 ,during these  
months the land is continually heated   
day and night to a higher temperature   
than the water in the ocean south of it4
 ,the winds are probably not so severe  
during the night as through the day1 as 
the difference between the temperature  
of the land and the water will not be so
 great during the night2 and difference 
of temperature between two points       
usually means a proportional difference 

in the velocity of the wind4 ,there is a
 time in the fall and spring1 while     
there is a struggle between the         
temperature of the land and water for   
supremacy1 when the winds are variable1 
attended with local storms somewhat as  
we have them in the temperate zone4 ,but
 after the sun has moved south to a     
sufficient extent the land of ,india    
loses more heat at night than is stored 
up in the day2 hence the conditions     
during the winter months are reversed1  
the water is constantly warmer than the 
land1 and there is a constant wind      
blowing from the land to the ocean1     
which continues until ,april1 when after
 a season of local storms the conditions
 are established in the opposite        
direction4 ,these winds are called      
monsoons4  ,the word monsoon is probably
 derived from an ,arabic word meaning   
seasons4 ,it is a peculiarity of this   
monsoon that in summer it blows in a    
northeasterly direction from the sea and
 in the winter in a southwesterly       

direction from the land4 ,this          
divergence from a direct north and south
 is caused by the rotation of the earth 
and the explanation is the same as that 
we have given for the trade winds4  ,in 
the southern latitudes there is a       
comparatively constant condition of wind
 and weather1 because the surface of the
 globe in these regions is mostly water2
 but in the north1 where most of the    
land surface is located1 we have a very 
different and a very complicated set of 
conditions1 as compared with the        
southern zones4  ,the freaks of wind and
 weather that we find prevailing upon   
the ,north ,american continent are not  
so easily accounted for as the phenomena
 heretofore discussed4 ,in the northern 
part the land reaches far up toward the 
north pole1 while on the west lies the  
,pacific ,ocean1 which merges into the  
,arctic ,ocean at ,bering ,strait4 ,the 
climate of the western coast is affected
 by a warm ocean current that sets up as
 far north as ,alaska1 while high ranges

 of mountains prevent the effects of    
this warm current from being felt inland
 to any great extent2 all of which helps
 to complicate any theory that may be   
advanced regarding changes of weather4  
,aside from the changes of temperature  
that are due to the seasons1 which are  
caused by the oscillating motion of the 
earth between the limits of the ,tropic 
of ,cancer on the north and the ,tropic 
of ,capricorn on the south1 there are   
other changes constantly taking place in
 all seasons of the year4 ,while it is  
not difficult to account for the change 
of seasons and the gradual change of    
temperature that would naturally        
follow--owing to the difference of angle
 at which the sun's rays strike the     
earth--it is more difficult to account  
for the violent changes that occur      
several times during the progress of a  
season1 as well as the less violent ones
 that come every few days4 ,in fact1 it 
rarely happens that the temperature is  
exactly the same on any two successive  

days during the year4 ,the diurnal      
changes are easily accounted for by the 
rotation of the earth on its axis each  
day4 ,but there is another class of     
phenomena with which the weather man has
 to struggle when he is making up a     
forecast of the weather from day to day4
  ,in order that we may proceed         
intelligently1 let us say a word about  
the barometer4 ,we speak of high and low
 barometer1 and we make the instrument  
with graduations marked for all kinds of
 weather1 which really mean but very    
little4 ,the reading of a single        
barometer alone will give us but a faint
 idea of what is really going to happen 
from day to day4 ,but if we have a      
series of barometers located at         
different stations scattered all over   
the continent and connected at          
headquarters by telegraph1 so that we   
can have the readings from a whole      
series of barometers at once1 then it   
becomes a very useful instrument4 ,a    
barometer may read low at one station by

 the scale1 but may be high with        
reference to some other barometer that  
reads very low4  ,what is a barometer8  
,if we should take a glass tube closed  
at one end1 the area of the cross       
section of which is one inch square1 and
 fill it with mercury1 and while thus   
filled plunge the open end into a vessel
 of mercury1 it will be found that the  
amount of mercury remaining in the tube 
above the level of the mercury in the   
vessel will weigh about fifteen pounds1 
if the experiment has been performed at 
sea-level4 ,this will vary1 however1    
according to the temperature of the air4
 ,of course barometers are tested when  
the air is at a certain temperature4 ,if
 the weight of mercury in the tube is   
fifteen pounds1 since it is sustained by
 the air pressing down on the mercury in
 the open vessel1 it shows that the     
air-pressure on that open vessel is     
equal to fifteen pounds to the square   
inch4 ,in practice1 of course1 the tubes
 are made very much smaller4 ,if the air

 changes so that it is lighter than     
normal the mercury will fall in the     
tube1 because the pressure on the       
mercury in the open vessel is less than 
fifteen pounds to the square inch4 ,and1
 again1 conditions may arise that will  
condense the air and make it for the    
time being weigh more than fifteen      
pounds to the square inch1 in which case
 the mercury will rise in the tube4     
,thus it will be seen that the barometer
 will register the slightest change in  
air pressure4  ,let us dwell for a      
moment on the causes of what are        
commonly called changes of weather1 when
 we will again revert to the use of the 
barometer4  ,the use of the telegraph in
 connection with the establishment of a 
weather bureau having stations for      
observation at convenient points        
throughout the country has contributed  
much to the science of meteorology4 ,it 
is found that there are areas of high   
and low pressure existing at the same   
time in different parts of the country4 

,these usually have their origin in the 
far northwest1 and follow each other1   
sweeping down the eastern side of the   
,rocky ,mountains and gradually bending 
easterly and from that to northeasterly 
by the time they reach the ,atlantic    
coast4 ,the areas of low pressure are   
called cyclones1 while the areas of high
 pressure are called anti-cyclones4 7,by
 cyclone we do not mean those cloud     
funnels commonly called by that name    
that form at certain times of the year  
in certain sections of the country and  
produce such destruction of life and    
property4 ,these storms are usually     
confined to a narrow strip and are      
short-lived4 ,they arise undoubtedly    
from local conditions4 ,a description of
 these tornadoes--for such is their true
 name--will be given in some future     
chapter47  ,these centers of high and   
low pressure may be several hundred     
miles apart4 ,in the area of high       
pressure1 if it is in the winter season1
 the weather is unusually clear and     

cold1 and generally clear and fairly    
cool at any season1 and while there may 
be some wind it is not so strong as in  
the cyclone or low-pressure center4 ,at 
this point it will be warmer and winds  
will prevail1 with rain or snow1 the    
winds varying in direction and intensity
 at a given point as the cyclone moves  
forward4 ,in the center of these        
cyclones and anti-cyclones there will be
 a region of comparative calm1 and the  
air is ascending at the center of the   
area of low pressure while it is pouring
 in on all sides from the area of high  
pressure where the air is compressed by 
a downward current from the upper       
regions4  ,the high-pressure or         
anti-cyclone system usually covers a    
larger area than the low-pressure       
system1 where the air is ascending4     
,while the air moves laterally from high
 to low1 it does not move in a direct   
line4 ,the air movement outside of the  
high-pressure center is usually not at a
 very high speed1 but in northern       

latitudes in the direction of the hands 
of a clock4 ,as it circles around it    
widens out spirally until it reaches the
 edge of a low-pressure system1 when it 
bends in its course and moves in the    
other direction around this center1 but 
constantly moving inward toward it in a 
spiral form and in a direction that is  
reverse to that of the hands of a clock4
 ,when the air current comes within the 
influence of a low-pressure or cyclonic 
system the velocity of its movement is  
very much accelerated until it has moved
 into the zone of quiet air in the      
center1 where it is ascending4  ,in the 
upper regions of the atmosphere there   
are counter currents flowing in the     
opposite direction4 ,the downward flow  
at the area of high pressure compresses 
the air near the surface of the earth   
and rarefies it in the higher regions of
 the atmosphere1 while the opposite     
effect is going on over the center of   
low pressure1 the air being rarefied    
nearer the surface of the earth1 but    

condensed above normal in the higher    
regions by the upward current1 which    
causes an overflow back toward the      
rarefied upper regions over the area of 
high pressure4  ,it will be observed    
that the ordinary storm has a compound  
motion4 ,the whole system moves in an   
easterly direction1 while the winds are 
blowing spirally about the storm center4
 ,if we should be in the track of a     
moving storm so that its center passed  
over us the winds at the beginning would
 blow in one direction and then there   
would come a subsidence until it had    
moved forward through the quiet zone1   
when we should feel the wind in the     
opposite direction until the area of low
 pressure had moved forward into the    
region of high pressure4 ,the velocity  
of the wind will be determined by the   
difference of pressure between the areas
 and by the distance that the areas of  
high and low pressure are apart4 ,the   
steeper the grade the more rapidly the  
fluid will flow4  ,let us now have      

recourse1 for a moment1 to ,figs4 #a1   
#b1 and #c in order that the subject may
 be more fully understood4 ,in looking  
at these diagrams we should imagine     
ourselves looking ,south1 with the left 
hand to the ,east4  ,illustration3      
,,fig4 #a4  ,fig4 #a shows the general  
direction of the air movement between   
two areas--one of high and the other of 
low pressure4 ,the arrows show the      
general direction of the wind4 ,you will
 notice that in the upper regions it    
blows in an opposite direction from the 
air movement on the surface of the      
earth4  ,fig4 #b shows in a general way 
how the wind moves spirally around both 
centers4 ,over the area of high pressure
 the air descends spirally from the     
upper regions1 circling around a large  
area--it may be one hundred miles or    
more in diameter--in the direction of   
the movement of the hands of a clock4   
,illustration3 ,,fig4 #b4  ,but then the
 wind at the high-pressure area is      
lighter than it is at the low1 and      

circles outwardly until it finally moves
 off in the direction of a low-pressure 
area1 gradually bending in the other    
direction until finally it moves the    
reverse of the hands of a               
clock--although now it is in a smaller  
circle1 and with a more rapid motion4   
,it moves spirally and upwardly about   
the low-pressure area until it reaches a
 point in the upper air1 where it goes  
through the same gyrations in an        
opposite direction4 ,now imagine the    
whole combination moving from west to   
east at an average rate of thirty miles 
per hour1 and imagine further that this 
system is linked to other systems that  
are following along1 and you have some  
idea of the weather changes as they     
occur in the middle ,united ,states4    
,by referring to ,fig4 #c you will see  
why the wind changes its direction when 
a storm center passes over any point4   
,it has not only a spiral but also a    
forward movement4  ,illustration3 ,,fig4
 #c4  ,now let us go back to the        

barometer and see what part it plays in 
predicting changes in the weather4 ,at  
the area of low pressure the air is     
ascending1 as we have seen1 and1 owing  
to the peculiar way it ascends--by      
circling spirally upward around a region
 of comparative calm--it creates a      
partial vacuum1 which is more pronounced
 in the center of the area4 ,at the area
 of high pressure the air will be       
condensed by the descending current     
being arrested by the earth4 ,the       
descending current--coming1 as it does1 
from the upper and colder               
regions--accounts for the cool weather  
that most always prevails at a          
high-pressure area4 ,in order to know   
how great the change of weather is      
likely to be1 we must know what the     
readings of at least two barometers     
are--one at the high- and another at the
 low-pressure area4 ,if the difference  
between the readings of the two         
barometers is very great1 and the areas 
are comparatively close together1 we may

 expect the change to be sudden and     
violent4  ,high and low as applied to a 
barometer are only relative terms4      
,there is no fixed point on the index of
 the instrument that can be said to be  
arbitrarily high or low4 ,for this      
reason a single barometer is not of much
 use4 ,if it begins to fall from any    
point1 and falls rapidly1 it indicates  
that an area of a much lower pressure is
 approaching4 ,the same is true of a    
high-pressure area1 if the barometer    
rises rapidly from any point4  ,if we   
study the air motions in these systems  
sufficiently to get at least an inkling 
of the law of their movements1 it       
becomes a very interesting subject4     
,wind from whatever cause serves a      
wonderfully useful purpose in the       
economy of nature4 ,without wind1 heat  
and moisture could not be distributed   
over the face of the earth and our globe
 would not be a fit habitation for man4 
,how wonderful is the machinery of      
,nature1 that can first forge a world   

into shape and afterward decorate it    
with green grass and flowers that are   
watered by the early and latter rain6   
,,chapter ,,xii4  ,,local ,,winds4      
,there are so many causes that will     
produce air motion that it is often     
difficult to determine just what one is 
the chief factor in causing the         
direction of the wind at any particular 
time4 ,there are very many instances1   
however1 where the cause can be traced  
without difficulty2 many of these have  
already been mentioned and there are    
many more that might be4 ,of course1 as 
has been often stated1 there is only one
 remote cause for all winds1 and that is
 the sun1 coupled with the movements of 
the earth4 ,but there are certain local 
conditions that are continually         
modifying the phenomena of air movement4
 ,the velocity of winds as they occur   
from day to day varies very greatly with
 the height above the surface of the    
earth2 ordinarily the velocity at #ajjj 
feet above the earth will be more than  

three times greater than it is at #ej or
 #fj feet above1 and even at #fj feet   
the velocity is much greater than at the
 surface of the earth4 ,this is due     
partly to the retarding effect of       
friction caused by contact of the air   
with the earth's surface1 but more      
particularly by trees1 inequality of    
surface1 and other obstructions on the  
earth4  ,there is a variety of wind     
called mountain winds that arise from   
different causes4 ,as has been stated in
 a former chapter1 under ordinary       
conditions the air is more dense at     
sea-level than at any point above1 and  
the density is constantly changing from 
denser to rarer the higher we ascend4   
,suppose at a certain point1 say halfway
 up a mountain side1 the air has a      
certain density1 and if it is at rest   
the lines of equal density or pressure  
will seek a level1 just as water would  
under the same conditions4 ,suppose we  
start at a given point on the side of a 
mountain and run out on a level till we 

are #ajj feet in a perpendicular line   
above the side of the mountain1 the air 
contained within those lines will be in 
the shape of a triangle4 ,if now the sun
 shines upon the side of the mountain   
the air is warmed and expands according 
to a well-known law1 and the amount of  
expansion will depend upon the depth of 
the volume of air2 hence the point of   
greatest expansion in our figure will be
 where the air is #ajj feet deep1 and   
will gradually decrease as we go toward 
the mountain till we come to the point  
where our horizontal line makes contact 
with the mountain side4 ,at that point1 
of course1 there is no expansion1       
because there is no depth of air2 and   
the effect will be that the expanded air
 will overflow toward the mountain1 and 
be deflected up its sloping side4 ,if we
 apply this same principle to the whole 
mountain side we can see that there will
 be1 during the day1 a constant current 
of air flowing up the mountain4 ,as     
night comes on this upward movement will

 cease and there will be a season of    
quiet until the earth has become colder 
than the air1 and we have a phenomenon  
of exactly the opposite kind1 when the  
air contracts instead of expands1 which 
produces a downward current from the    
mountain top4  ,these currents are as   
regular at certain seasons of the year  
as the land and sea breeze4 ,of course1 
they may be obliterated for the time    
being1 by the presence of a stronger    
wind due to some other cause1 such as   
during the prevalence of a storm4 ,in   
some of the regions of ,california      
hottest during the day time1 the nights 
are made endurable1 and even delightful1
 by the cool breezes that sweep down    
from the tops of the mountains4 ,it     
often happens that on the shady side of 
a high and steep mountain where the     
sun's rays strike it so obliquely1 if at
 all1 that the earth will be but little 
heated1 there will be a vast mass of    
cold air stored up4 ,after the valley   
has become intensely heated by the sun  

there is an ascending current of air    
which in turn causes a down rush of the 
cold body of air from the mountain side4
 ,these local winds are frequently very 
severe1 only lasting1 however1 for a    
short time1 until an equilibrium of     
temperature and density has been        
established4 ,a wonderful exhibition of 
this sort of wind is said to occur at   
certain times of the year on the coast  
at ,tierra del ,fuego1 where a blast    
which they call the ,williwaus1 comes   
down from the mountain side1 without    
warning1 with such tremendous force that
 no ship could stand the strain if it   
should continue for any length of time4 
,fortunately the shock does not last    
more than eight or ten seconds1 when it 
is followed by a perfect calm4 ,it is as
 though a great volume of air had been  
fired from some enormous cannon from the
 top of the mountain to the sea4 ,the   
water is pulverized into a spray that is
 driven in every direction4  ,sometimes 
these violent blasts occur in the ,alps1

 but from a very different cause4       
,avalanches of great extent often take  
place on the sides of the mountains1    
when a vast amount of material1 equal to
 three or four hundred million cubic    
feet of earth1 will fall several        
thousand feet4 ,often an avalanche of   
this kind will produce a wind1 which is 
confined1 of course1 to a restricted    
area1 that is said to be so violent as  
to tear one's clothes into shreds4 ,this
 is not caused by any difference of     
temperature1 but by a violent           
compression4  ,there is a peculiar wind 
that occurs in ,switzerland1 often1     
between the months of ,november and     
,march4 ,these winds last from two to   
three days and are of great             
violence--especially near the mountains4
 ,they are warm and dry and are caused  
by an area of low barometer and an      
ascending current of air occurring at   
some point north of the ,alps1 which    
causes the air from ,italy to flow over 
the ,alpine range1 causing a tremendous 

precipitation of snow and rain1 which   
not only takes the moisture from the    
air1 but sets free in the form of heat  
the energy that was stored in the       
process of evaporation1 and this1       
together with the compression of the air
 as it flows down the slope of the      
mountains1 makes it hot and dry4 ,this  
wind is called the ,fohn4  ,there is a  
similar condition of things existing on 
the eastern slope of the ,rocky         
,mountains which has a modifying effect 
upon the climate of parts of ,colorado1 
,wyoming1 ,montana1 also extending up   
into ,british ,america4 ,this wind1     
which is here called chinook1 arises    
from causes similar to those that are   
active in ,switzerland that give rise to
 the fohn wind4  ,there is a wind called
 the blizzard that is felt most keenly  
in ,montana and the ,dakotas during the 
winter1 which is exceedingly cold and   
lasts sometimes for a period of #ajj    
hours4 ,the temperature falls at times  
#cj or #dj degrees below zero and the   

wind maintains a velocity of from forty 
to fifty miles an hour4 ,these winds    
spread eastward as far as ,illinois1 but
 not with the same severity1 and they   
move southward to the ,gulf of ,mexico1 
spreading over the ,states of ,texas and
 ,louisiana1 and are there called       
northers4 ,it is exceedingly dangerous  
to be caught in a blizzard in the       
,dakotas1 where the wind reaches its    
greatest velocity and the cold its      
lowest temperature--especially when the 
wind is accompanied1 as it frequently   
is1 by severe snowing4 ,by the time it  
reaches the ,gulf ,states it is very    
much modified as to temperature1 but it 
is a very disagreeable wind in that     
portion of the country1 because of the  
exceeding dampness of the air4 ,one     
would be much more comfortable in dry1  
still air1 even if it were many degrees 
below zero1 than in an air freighted    
with moisture1 although the temperature 
has not fallen to the freezing point4   
,there are hot winds called by different

 names according to the localities in   
which they occur4 ,in southern          
,california at certain seasons of the   
year the inhabitants are afflicted with 
what they call a desert wind that blows 
from the heated regions of ,arizona     
toward the ,pacific ,ocean4 ,the        
temperature sometimes reaches #abj      
degrees ,fahrenheit1 and persons have   
been known to perish from the effects of
 these hot winds in open boats out on   
the water before they could reach land4 
,hot winds prevail on the plains of     
,kansas during the months of ,july and  
,august that are phenomenal in their    
intensity1 so much so that if they were 
widespread and of long continuance1 like
 the northern blizzard1 they would be   
attended with great loss of life and    
destruction to vegetation4 ,fortunately1
 they come in narrow streaks and in most
 cases do not blow more than from ten to
 thirty minutes at a time4 ,these hot   
belts are sometimes not over #ajj feet  
wide1 and again they are as much as     

#ejj4 ,they are so hot and dry that     
green leaves and grass are rendered as  
dry as powder in a few minutes4 ,these  
winds are probably caused by the fact   
that at this season of the year1 when   
the prevailing wind is southwesterly1   
the air becomes heated to a great       
height1 and are the resulting effect of 
certain combinations of air currents in 
the higher regions of the atmosphere    
that force the already heated air toward
 the earth4 ,as the air descends it is  
more and more compressed1 which causes  
it to become more and more heated4 ,we  
have already described the heating      
effect of compression upon air as shown 
by the experiment with the fire syringe4
 ,it was shown that air at normal       
temperature could be suddenly compressed
 into so small a space that the         
condensed heat1 which was before        
diffused through the whole bulk of air  
at normal pressure1 was sufficient to   
cause ignition4 ,a cubic yard of air on 
the surface of the earth would occupy a 

much larger space if carried a mile     
above it4 ,from this it is easy to see  
that if a volume of air at that height  
had a temperature of #gj or #hj degrees 
it would be very hot when condensed into
 a very much smaller volume1 as it would
 be if it were forced down to the       
surface of the earth4 ,these winds are  
the result of some superior force that  
is active in the upper regions of the   
atmosphere1 because it is natural for   
heated air to rise1 and this is what    
happens when the power that forced it   
down to the earth is no longer active to
 hold it there4  ,reference has been    
made in a former chapter to tornado     
winds2 they are rather exceptional      
phenomena and not thoroughly understood4
 ,the winds seem to blow in from all    
directions toward an area of very low   
pressure at a single point4 ,the spiral 
motion that is common to all cyclones1  
in a tornado seems to be gathered up    
into a condensed form1 like a funnel4   
,the direction of movement is the same  

as that of the cyclone--that is1 in the 
reverse direction to that of the hands  
of a watch4 ,the upward motion of the   
air inside of the funnel is at a rate of
 over #agj miles an hour4 ,the onward   
movement of the whole system is about   
thirty miles per hour4  ,tornadoes occur
 with greater frequency in the ,united  
,states than in any other section of the
 globe4 ,tornadoes seldom occur in      
winter1 except perhaps in the ,southern 
,states4 ,they are more frequent in the 
month of ,may than at any other time    
during the year1 although they occur    
sometimes in ,april1 ,june1 and ,july4  
,between #ahgj and #ahij about          
sixty-five destructive tornadoes        
occurred in the ,united ,states1        
involving great loss of life and        
property4 ,when a tornado moves off the 
land on to the ocean it may become what 
is termed a waterspout4 ,these probably 
never originate on the water1 but after 
they have once formed may be carried    
over the water to a considerable        

distance4 ,a tornado was never known to 
originate on the shores of ,lake        
,michigan1 but there are a few instances
 7the most notable one being the ,racine
 tornado7 when they have reached the    
lake after having traveled from some    
distant point inland4  ,the ,racine     
tornado--so called because it destroyed 
a large portion of that city--happened  
fifteen or more years ago4 ,the tornado 
originated about #ajj miles southwest of
 ,racine1 ,wis41 in northern ,illinois4 
,the funnel-shaped cloud passed over the
 lake1 but the tornado character of the 
storm was broken up before it reached   
the other shore4  ,when a tornado passes
 from land to water it becomes a        
waterspout only when the cloud-funnel   
hangs low enough and the gyratory energy
 is sufficiently great4 ,there is a     
great pressure on the water outside of  
the funnel and almost a perfect vacuum  
inside4 ,this latter fact contributes   
largely to the destructive power of the 
tornado4 ,when a funnel is central over 

a building a sudden vacuum is created   
outside of it and it bursts outwardly   
from the internal air pressure4         
,,chapter ,,xiii4  ,,weather            
,,predictions4   ,to predict with any   
great accuracy what the weather will be 
from day to day is a somewhat           
complicated problem1 and1 as all of us  
have reason to know1 weather predictions
 made by those who have the matter in   
charge and are supposed to know all     
about it often fail to come to pass4    
,the real trouble is that they do not   
know all about it4 ,there are so many   
conditions existing that are outside of 
the range of barometers1 thermometers1  
anemometers1 and telegraphs that no one 
can tell just when some of these unknown
 factors will step in to spoil our      
predictions4  ,in very many cases1      
perhaps in a large majority of them1 the
 predictions made by the weather bureau 
substantially come to pass4 ,it has been
 stated in former chapters that the     
changes of weather accompany the        

movements of what are called cyclones   
and anti-cyclones1 the cyclone being    
accompanied by low barometric pressure  
and the anti-cyclone by a higher one4   
,the winds of the cyclone move spirally 
around the center of lowest depression  
with an upward trend1 the motions being 
in a direction reversed to that of the  
hands of a clock4 ,in the centers of    
high pressure the current is downward   
instead of upward and the direction of  
the wind around it is opposite to that  
around the low-pressure area4 ,the      
fundamental factor in predicting the    
weather is the direction of movement of 
these areas of low pressure4 ,in almost 
all cases the direction of movement is  
from the west to the east1 but not      
always in a straight line4 ,these       
movements1 however1 are classified so   
that after the direction has become     
established one can predict with        
considerable accuracy as to whether it  
will move in a curved or a straight     
line4 ,by movement we do not refer to   

the direction of the wind at any        
particular point1 but the onward        
movement of the whole cyclonic system1  
which is usually from twenty-five to    
thirty miles an hour1 but in some cases 
the speed is much greater4  ,not only   
does the upward movement of the whole   
system vary1 but the velocity of the    
wind around any given cyclonic center   
varies4 ,there are about eleven classes 
of cyclones that appear in the ,united  
,states1 each class having its own path 
of movement and origin4 ,a large number 
of these appear to originate north of   
the ,dakotas1 and move directly east to 
the ,gulf of ,st4 ,lawrence4 ,three     
other classes originate on about the    
same line1 a little west1--say1 north of
 ,montana1--moving first in a           
southeasterly direction1 passing over   
the center of ,lake ,michigan and       
bending northerly through ,lake ,ontario
 and finally landing in the ,gulf of    
,st4 ,lawrence4 ,two other classes start
 at the same point1 one of them going as

 far south as ,cincinnati1 and the other
 as far south as ,montgomery1 ,ala41 and
 both turning at these points           
northeasterly to the ,gulf of ,st4      
,lawrence4 ,two other classes originate 
in ,colorado1 one moving in a           
northeasterly direction slightly curved1
 and the other directly east4 ,still    
others have their origin farther south  
in the ,gulf of ,mexico1 and move in a  
northeasterly direction4 ,very rarely   
they originate in the ,atlantic east of 
,savannah1 moving first in a            
northwesterly direction1 but finally    
bending to the northeast4  ,every day   
there is a weather map made up showing  
the locations of the high and low       
barometers1 direction of wind1 lines of 
equal pressure1 as well as those of     
temperature4 ,by study from year to year
 all of these phenomena have become     
systematized1 so that by tracing an area
 of low barometer from its origin in its
 progress easterly it is soon seen to   
fall under one of these classes and we  

are able to predict about what its      
course will be4 ,knowing the speed of   
its movement as well as the velocity of 
wind and all the conditions attending   
it1 taken in connection with the weather
 conditions in the region for which the 
prediction is made1 an expert can       
ordinarily forecast with some degree of 
accuracy4 ,after all that can be said1  
however1 weather predictions based upon 
maps are and have been far from         
satisfactory4 ,one who has been a close 
student of local conditions for a number
 of years will often predict with as    
great accuracy as the weather bureau4   
,areas of low pressure are followed     
sooner or later by a fall of            
temperature2 this is especially true in 
the winter months4 ,sometimes this fall 
is very marked1 and then it is called a 
cold wave4 ,these sudden changes of     
temperature are not thoroughly          
understood1 but are supposed to be due  
partly at least to rapid radiation of   
heat into the upper regions1 as the     

clear atmosphere which usually attends  
areas of high pressure is favorable to  
such a condition4 ,undoubtedly1 too1    
there are dynamic causes1 forcing the   
colder air from the upper regions to the
 earth1 when it immediately flows off   
toward an area of low barometer4        
,long-time predictions are purely       
guesses4 ,they sometimes guess on the   
right side1 and this gives them courage 
to make another4 ,it is an old saying   
that all signs fail in dry weather4 ,in 
time of a drought it is true that the   
indications which at ordinary times     
would be surely followed by a rain are  
of no value4 ,when a season is once     
established1 either as a rainy season or
 a dry season1 it is likely to persist  
in this character until a change comes  
that is produced by the movement of the 
sun in its course northerly and         
southerly1 and the change produced from 
this cause requires several weeks of    
time4  ,if accurate weather predictions 
could be made for a long time in        

advance1 or for even a week1 they would 
be of incalculable value4 ,but it is    
doubtful if ever this will be brought   
about1 as there are too many necessarily
 hidden factors which enter into the    
calculations4 ,if stations could be     
established all over the oceans with    
sufficient frequency1 and an equal      
number at a sufficient altitude in the  
air1 ,i have no doubt that much that is 
now mysterious might be made plain4     
,,chapter ,,xiv4  ,,how ,,dew ,,is      
,,formed4   ,reader1 did you ever live  
in the country8 ,were you ever awakened 
early on a summer's morning to go for   
the cows8 ,did you ever wade through a  
wheat field in ,june--or the long grass 
of a meadow--when the pearly dewdrops   
hung in clusters on the bearded grain1  
shining like brilliants in the morning  
sun8 ,have you not seen the blades of   
grass studded with diamonds more        
beautiful than any that ever flashed in 
the dazzling light of a ballroom8 ,if   
not1 you have missed a picture that     

otherwise would have been hung on the   
walls of your memory1 that no one could 
rob you of4  ,everyone has noticed that 
at certain times in the year the grass  
becomes wet in the evening and grows    
more so till the sun rises the next day 
and dispels the moisture1 and this when 
no cloud is seen4 ,dew is as old as the 
fields in which grass grows4 ,it was as 
familiar to the ancients as it is to us1
 and yet it is only about three-quarters
 of a century since the cause of it has 
been understood4 ,we even yet speak of  
the dew falling like rain4 ,in former   
times some scientists supposed that it  
was a fine rain that fell from the      
higher regions of the atmosphere4       
,others supposed it to be an emanation  
from the earth1 while still others      
supposed it was an exudation from the   
stars4       ,by his knowledge the      
depths are broken up and the clouds     
drop down dew 7,prov4 iii4 #bj74  ,the  
first experiments carried on in a       
scientific way were by ,dr4 ,wells1 a   

physician of ,london1 between the years 
#ahaa and #ahad4  ,everyone has noticed 
in warm weather the familiar phenomenon 
of water condensed into drops on the    
outside of a pitcher or tumbler         
containing cold water4 ,this            
condensation is dew4 ,it always forms   
when the conditions are right1 summer   
and winter4 ,in cold weather we call it 
frost4 ,it has been stated in a former  
chapter on evaporation that the capacity
 of the air for holding moisture in a   
transparent form depends upon its       
temperature4 ,if the temperature is at  
the freezing point it will contain the  
#afjth part of the atmosphere's own     
weight as aqueous vapor4 ,if it is #fj  
degrees ,fahrenheit the air will retain 
six grains of transparent moisture to   
the square foot of air1 while at #hj    
degrees it will contain nearly eleven   
grains4 ,when the air is charged with   
this vapor to the point of saturation   
7which point varies with the            
temperature7 a slight depression of the 

temperature is sufficient to condense   
this vapor into cloud or drops of water4
 ,between #ahab and #ahad ,dr4 ,wells   
made a series of experiments with flocks
 of cotton wool4 ,he weighed out pieces 
of equal weight and attached a number of
 them to the upper side of a board and  
as many more to the lower side1 and     
exposed it to the night air under       
varying conditions4 ,one experiment was 
made with a board four feet from the    
earth1 so that half of the bunches of   
cotton faced the ground and the other   
half the sky4 ,he found upon weighing   
these after a night's exposure under a  
clear sky that the cotton wool on top of
 the board had gained fourteen grains in
 weight from the moisture1 or dew1 that 
had formed upon it1 while the same      
amount of cotton on the under side of   
the board had only increased four       
grains4 ,he tried further experiments by
 making little paper houses1 or boxes1  
to cover a certain portion of grass or  
vegetation4 ,he found that while there  

would be a heavy dew on the grass       
outside there was little or none within 
the inclosure4 ,these experiments were  
conducted in various ways and closely   
watched to see that none of the         
phenomena were in any way connected with
 falling rain4 ,it has been determined  
that substances like grass and green    
leaves of all kinds1 hay and straw1     
while they are poor conductors of heat1 
are excellent radiators4 ,in another    
chapter we have referred to this quality
 of straw1 that is taken advantage of by
 the inhabitants of hot countries in the
 manufacture of ice and in our own land 
for storing it4  ,perhaps everyone who  
has lived in the country has noticed    
that on a summer's morning when the     
grass is laden with dewdrops a gravel   
walk or a dusty road will be perfectly  
dry4 ,this is due to the fact that the  
gravel will retain heat and not radiate 
it1 for a much longer time than grass or
 green leaves4 ,dew begins to form upon 
the grass very soon after the sun is set

 because the moment the sun's rays are  
withdrawn the heat is rapidly radiated  
by the blades of grass1 which cools the 
earth under it and the air above and    
surrounding it1 so that if the air is   
anywhere near the moisture saturation   
point on cooling at the surface of the  
ground it will readily give up a part of
 its moisture1 which condenses in drops 
upon the blades of grass4  ,if the night
 is still and clear and there is much   
moisture in the air1 the dew will be    
heavy1 but if the night is cloudy there 
will be little or no dew formed4 ,the   
clouds form a screen between the earth  
and the upper regions of the atmosphere1
 which prevents the heat from radiating 
to a sufficient extent to form dew4 ,for
 the same reason no dew will form under 
a light covering spread over the ground 
even at some distance above it4 ,the    
covering acts as a screen1 which        
prevents the heat from radiating to the 
dew point4 ,from what has gone before it
 will be seen that if the atmosphere is 

not charged with moisture up to the     
point of saturation it will require a   
greater amount of depression of         
temperature to cause condensation1 and  
this is why we usually have heavier dews
 in ,june when the air is more highly   
charged with moisture than we do in     
,august when it is dry4 ,this also      
accounts for the ice clouds1 called     
cirrus1 being formed so high up in the  
atmosphere during dry weather4 ,there is
 so little moisture in the air that it  
requires a very great difference of     
temperature to cause condensation to    
take place1 and the necessary depression
 is not reached in these cases except at
 an altitude of several miles4  ,dr4    
,wells has shown that if we take the    
reading of two thermometers on a clear  
summer night1 one of them lying on the  
grass and the other suspended two feet  
above it1 we shall find that the one    
lying on the grass will read #h or #aj  
degrees lower than the one suspended in 
the air4 ,if the night is still there   

will be a cold stratum of air next to   
the earth1 which will not tend to       
diffuse itself to a very great degree   
and dew will form4 ,if1 however1 it is  
cloudy or the wind is blowing there is  
rarely any formation of dew4 ,the reason
 in the former case1 as we have         
explained1 is that the radiated heat is 
held down to the earth in a measure1 and
 in the latter case there is a constant 
change of air2 so that in either case no
 part of it is allowed to cool down     
sufficiently to precipitate moisture4   
,it is a curious fact that often there  
will be a heavier dew under the blaze of
 a full moon on a clear night than at   
any other time4 ,the moon has no screens
 about it of any kind to obstruct the   
free radiation of heat4 ,it is supposed 
to be a dead cinder floating in space   
and not surrounded by an atmosphere1 so 
that the sun's rays have full effect    
upon it during the time it is exposed to
 them1 and at that time it becomes      
heated to a temperature of something    

like #gej degrees ,fahrenheit4 ,for half
 the month1 say1 the sun is shining     
continuously upon all or a part of it4  
,in other words1 the days and nights of 
the moon are about two weeks long4 ,the 
moon does not revolve upon its own axis 
like the earth1 therefore the same side 
or a portion of it is exposed to the sun
 for #ad days4 ,during the time that the
 moon is in the earth's shadow it is    
supposed to fall to #ahg degrees below  
zero1 which is #bai degrees below the   
freezing point4 ,when the moon is full  
and is heated up to over #gjj degrees   
there is sufficient heat radiating from 
it to be felt sensibly upon the face of 
the earth1 and it would be felt if it   
were not for the great envelope of      
atmosphere and its attendant cloud      
formations that surround the earth4     
,there are but few days in summer when  
there is not a haze in the atmosphere1  
although we call the sky clear1 which   
intensifies the light and gives         
everything a warmer tone4 ,the heat     

coming from a full moon on a clear night
 is absorbed in causing the aqueous     
vapors that are partly condensed in the 
higher regions of the atmosphere1 to be 
reabsorbed into transparent vapor4 ,this
 clears away the heat screen in the     
atmosphere and allows radiation to go on
 more rapidly at the earth's surface1   
and thus cools it to a greater extent   
when the moon is shining brightly than  
when it is dark and in the shadow of the
 earth4  ,as we have already mentioned1 
the cold that is produced by radiation  
through the blades of grass and other   
radiating substances may be indicated by
 placing one thermometer on the ground  
and fixing another at some point in the 
air4 ,sometimes the difference is very  
marked1 amounting to as much as #bj or  
#cj degrees4 ,if under these conditions 
a cloud floats overhead1 forming a heat 
screen1 its presence will be readily    
noticed by a rise in the thermometer4   
,radiation into the upper regions of the
 atmosphere is checked1 which causes a  

sudden rise in the temperature near the 
surface of the earth4 ,by taking        
advantage of this principle of heat     
radiation from the earth's surface it is
 a very easy matter to protect tender   
vegetation from even quite a severe     
frost1 if it occurs in the early fall1  
by a slight covering1 such as thin      
paper4 ,the paper will act as a heat    
screen and in a measure prevent the heat
 from radiating from the earth          
immediately under it4 ,frost--which of  
course is but frozen dew--at this season
 of the year will form on a still autumn
 night1 although the atmosphere at some 
distance above the ground is some       
degrees above the freezing point4 ,the  
reason for this will be obvious when we 
consider the facts that have been set   
forth concerning the power of radiation 
to produce cold4  ,it has been estimated
 by meteorologists that the amount of   
water condensed upon the surface of the 
earth in the form of dew amounts to as  
much as five inches1 or about           

one-seventh of the whole amount of      
moisture that is evaporated into the    
air4 ,it will thus be seen that dew     
performs an important part in supporting
 vegetation4  ,the same operation in    
nature's great workshop that forms the  
dews of summer creates the frosts of    
winter4 ,the moisture in cold weather is
 condensed the same as in warm4 ,when it
 is condensed at the surface of the     
earth we have the phenomenon of frost1  
but when condensed in the upper regions 
of the atmosphere we have that of snow4 
,heat radiation from the earth goes on  
in winter1 which is evidenced by the    
fact that a thick covering of snow is a 
great benefit to vegetation as a        
protection against the injurious effects
 of frost4 ,the writer has seen flowers 
blooming abundantly at an altitude of   
#ab1jjj feet above the sea-level1       
protected only by the friendly shelter  
of a snowbank4 ,in some cases the       
blooming flowers were in actual contact 
with the snow4 ,by experiment it has    

been determined that the earth under a  
thick coating of snow is usually warmer 
by nine or ten degrees than the air     
immediately above the snow covering4    
,,chapter ,,xv4  ,,hailstones ,,and     
,,snow4   ,a hailstone is a curious     
formation of snow and ice1 and most of  
the large hailstones are conglomerate in
 their composition4 ,they are usually   
composed of a center of frozen snow1    
packed tightly and incased in a rim of  
ice1 and upon this rim are irregular    
crystalline formations jutting out in   
points at irregular distances4          
,frequently1 however1 we find them very 
symmetrically formed as to outline1 and 
the snow centers are almost without     
exception round4 ,hailstones and        
hailstorms differ in different climates1
 but they are more pronounced in the    
torrid than in the temperate zone4      
,historians give accounts of hailstones 
of enormous size2 the very large        
hailstones being undoubtedly            
aggregations of single stones that have 

been thrown together and congealed in   
the clouds during their fall to the     
earth4  ,it is recorded that on ,july   
#d1 #ahai1 hailstones fell at           
,baconniere measuring fifteen inches in 
circumference1 and very symmetrically   
formed1 with beautiful outline4         
,hailstones in ,india are said to be    
very large--from five to twenty times   
larger than those in ,england or        
,america--seldom less than walnuts and  
often as large as oranges and pumpkins4 
,it is recorded that in #ahbf1 during a 
hailstorm at ,candeish1 the stones      
perforated the roofs of houses like     
cannon shot1 and that a single mass fell
 that required several days to melt1    
weighing over #ajj pounds4 ,it is       
further recorded that on ,may #h1 #ahcb1
 a conglomerate mass of hailstones fell 
in ,hungary a yard in length and nearly 
two feet in thickness4 ,still another   
instance is recorded of a hailstone     
having fallen in #ahdi of nearly twenty 
feet in circumference4 ,this hailstone  

is said to have fallen upon the estate  
of ,mr4 ,moffat of ,ord4 ,we will only  
ask our readers to listen to one more   
hailstone story1 in which it is related 
that during the reign of ,tippoo1       
sultan1 a hailstone fell as large as an 
elephant4 ,undoubtedly one of two things
 was true regarding this latter story2  
it was either a very large hailstone or 
a very small elephant4 ,the historian   
fails to give the size of the elephant4 
,there is no doubt1 however1 but that   
hailstones may adhere and form large    
masses owing to the violent agitation of
 the elements that always attends a     
hailstorm4  ,hailstorms are almost      
universally attended by constant and    
heavy thunder and lightning1 together   
with violent winds4 ,they usually occur 
on a very hot day1 and when the air is  
filled to saturation with moisture4     
,when this is the case a column of air  
is very highly heated at some point1    
when it ascends with great force into   
the upper regions of the atmosphere to a

 greater altitude than is common in the 
case of ordinary thunderstorms4 ,here it
 meets with an intensely cold body of   
air1 when it is suddenly condensed and  
readily frozen as soon as condensed1    
which not only forms hailstones1 but    
sets free the energy that has been      
carried up in the moisture globules4    
,this results in frequent electrical    
discharges1 causing great waves of      
condensed and rarefied air1 which1 in   
the rarefied portions1 produces still   
more intense cold2 so that we have the  
conditions for a mighty struggle between
 the elements1 which is intensified by a
 constant and terrific electric         
cannonade4 ,undoubtedly there are also  
whirlwinds in the cloud1 similar to     
those that sometimes visit the earth1   
which would tend to gather up the       
hailstones and aggregate them into large
 masses4 ,it is a mighty battle between 
the moisture-laden1 superheated air1    
ascending from the surface of the earth1
 and the powers residing in the upper   

regions of cold4 ,nature is constantly  
struggling to find an equilibrium of her
 forces1 and a hailstorm is only one of 
the little domestic flurries that take  
place when she is setting her house to  
rights4 ,hailstorms are usually confined
 to very narrow limits1 and they can    
prevail on a grand scale only in hot    
climates1 where we have the conditions  
for wide differences of temperature     
between the upper and lower regions of  
the atmosphere2 and1 also1 where the    
conditions are favorable1 for an        
enormous amount of absorption of        
moisture into the atmosphere4  ,when    
snow is formed in the atmosphere1 the   
conditions are quite different from     
those of a hailstorm2 it is usually in a
 lower plane of the atmosphere1 and     
there is no violent commotion1 as is the
 case with the latter4 ,a volume of air 
laden with moisture comes in contact    
with a colder volume of air1 when       
condensation takes place1 as in the case
 of rain1 except that the moisture is   

immediately frozen4 ,in this case both  
volumes of air may be below the freezing
 point1 but one is very much colder than
 the other4 ,if the snow reaches the    
earth it will be because the air is     
below the freezing point all the way    
down4 ,snow is formed at all seasons of 
the year4 ,we may have a snowstorm on a 
high mountain when we have extreme heat 
at sea-level4  ,in summer time of course
 the snow melts as soon as it falls into
 a stratum of air with a temperature    
above the freezing point1 and continues 
its journey from that point as raindrops
 instead of snowflakes4 ,in the         
formation of a snowflake ,nature does   
some of her most beautiful work4 ,a     
snowflake first forms with six ice      
spangles1 radiating from a common       
center4 ,shorter ones form on these six 
spokes1 standing at an angle of about   
sixty degrees1 on each side of each     
spoke1 of such length and arrangement as
 to form a symmetrical figure or flower4
 ,they do not always take the same form1

 but follow the same laws that govern   
the formation of ice crystals4 ,the     
structure of a snowflake may be often   
found upon a window pane of a frosty    
morning4 ,here1 however1 the free       
arrangement of the parts of a snow      
crystal are interfered with by its      
contact with the window pane1 but while 
floating gently in the air there is the 
utmost freedom for the play of nature's 
forces as they apply to the work of     
crystallization4  ,the difference in    
structure of snowflakes is chiefly due  
to the conditions under which they are  
formed4 ,if the moisture is frozen too  
rapidly the molecular forces that are   
active in crystallization do not have   
time to carry out the work1 in its      
completeness of detail1 as it will where
 the freezing process1 as well as the   
condensing process1 goes on more slowly4
     ,,chapter ,,xvi4  ,,meteors4       
,meteors are the tramps of              
interplanetary space4 ,they sometimes   
try to steal a ride on the surface of   

the earth1 but meet with certain        
destruction the moment they come within 
the aerial picket line of our world's   
defense against these wandering vagrants
 of the air4 ,they have made many       
attempts to take this earth by storm1 as
 it were1 and many more will be made4   
,they fire their missiles at us by the  
millions every year with a speed that is
 incredible1 but thanks to the          
protecting influence of the great ocean 
of air that envelops our globe they     
become the victims of their own         
velocity4  ,meteors or shooting stars   
are as old as the earth itself1 and they
 are the material of which comets are   
made4 ,before it was determined what    
these meteors or shooting stars were1   
many theories were promulgated as to    
their origin4 ,one was that they were   
masses of matter1 large and small1      
projected by volcanic action from the   
face of the moon with such violence as  
to be brought within the attraction of  
the earth4 ,others supposed them to be  

the effect of certain phosphoric fluids 
that emanated from the earth and took   
fire in the upper regions of the        
atmosphere4 ,this1 however1 was mere    
speculation and without any scientific  
basis of fact4 ,anyone who has been an  
observer of shooting stars will have    
learned that there are certain periods  
of the year when they are more numerous 
than at other times2 notably in ,august 
and ,november4 ,then again there are    
longer periods of many years apart4 ,by 
persistent observation it has been      
established that there are great numbers
 of schools or collections of cosmic    
matter that fly through interplanetary  
space1 having definite orbits like the  
planets4 ,any one of these collections  
may be scattered through millions of    
miles in length4 ,a comet is simply one 
of these wandering collections of       
meteoric stones having a nucleus or     
center where the particles are so       
condensed as to give it a reflecting    
surface something like the planets or   

the moon4 ,this enables us to see the   
outline of the comet to the point where 
the fragments of matter become so       
scattered that they are no longer able  
to reflect sufficient light to reach our
 eyes4 ,the fringe of a comet1 however1 
may extend thousands or even millions of
 miles beyond the borders of luminosity4
  ,there is scarcely a day or night in  
the year when more or less of these     
meteoric stones do not come within the  
region of our atmosphere1 and when this 
happens the great velocity at which they
 travel is the means of their own       
destruction4 ,they become intensely     
heated by friction against the          
atmosphere just as a bullet will when   
fired from a gun--only to a greater     
extent owing to the greater velocity4   
,they disintegrate into dust which      
floats in the air for a time1 when more 
or less of it is precipitated upon the  
surface of the earth4 ,disintegrated    
meteors1 or star dust1 as they are      
sometimes called1 are often brought down

 by the rain or snow4 ,most of the      
shooting stars that we observe are very 
small1 resembling fire-flies in the sky1
 but once in a while a very large one is
 seen moving across the face of the     
heavens1 giving off brilliant           
scintillations that trail behind the    
meteor1 making a luminous path that is  
visible for some seconds4 ,these        
brilliant manifestations are due to one 
of two causes4 ,either there is a very  
large mass of incandescent matter or    
else they are so much nearer to us than 
in ordinary cases that they appear      
larger4 ,it is more likely1 however1    
that it is due to the former cause      
rather than the latter1 from the fact of
 its apparently slow movement as        
compared with the smaller shooting      
stars4 ,it has been determined by       
observation that the average meteor     
becomes visible at a point less than    
#ajj miles above the earth's surface4   
,it was found as far back as #ahbc that 
out of #ajj shooting stars twenty-two of

 them had an elevation of over          
twenty-four and less than forty miles2  
thirty-five1 between forty and fifty    
miles2 and thirteen between seventy and 
eighty miles4 ,it was determined by     
,professor ,herschel that out of sixty  
observations of shooting stars the      
average height of their first appearance
 was seventy-eight miles and their      
disappearance was at a point fifty-three
 miles above the earth4  ,it is a matter
 of history1 however1 that sometimes    
these meteoric stones descend to the    
surface of the earth before they are    
entirely disintegrated4 ,a fine specimen
 of this kind is to be seen in the      
,smithsonian ,institution4 ,there are   
over forty specimens of these aerolites 
7air-stones7 in the ,british ,museum1   
labeled with the times and places of    
their fall4 ,instances of falling to the
 earth are so rare that there is little 
to fear from these wandering missiles of
 the air4 ,we do not remember a case    
where life or property has suffered from

 the fall of a meteor4  ,this brings us 
to the consideration of the part which  
the great air envelope surrounding the  
earth plays as a protection against many
 outside influences4 ,for instance1 if  
it were not for the air1 millions of    
these meteoric stones would be showered 
upon our earth every year and at certain
 times every day1 which would render the
 earth untenable for human existence4   
,we should be at the mercy of those     
wandering comets whose fringes strike   
our atmosphere more or less deeply at   
frequent intervals4 ,it is not          
impossible that the earth may at some   
time pass directly through one1 and yet 
there is little danger that in such a   
case there would be more than an unusual
 display of celestial fireworks4  ,from 
the facts that have been above stated it
 will be apparent to anyone that the    
number of these meteoric stones in the  
air is being constantly reduced by their
 constant collision with the atmosphere 
and consequent reduction to ashes or    

dust4 ,another conclusion is that the   
earth must be gradually1 but            
imperceptibly perhaps1 increasing in    
size on account of the constant settling
 upon its surface of meteoric dust4     
,,chapter ,,xvii4  ,,the ,,sky ,,and    
,,its ,,color4   ,in the chapters on    
light in ,vol4 ,,ii4 it will be stated  
that we see all objects by a reflected  
light1 except those that are            
self-luminous1 such as the sun or any   
other source of light4 ,we see the moon 
and many of the planets entirely by     
reflection4 ,there are myriads of       
smaller objects1 too small to be seen as
 such1 even under a microscope1 that    
still have a power to reflect light that
 is sensible to our vision4 ,the air    
surrounding the globe is literally      
filled with these microscopic light     
reflectors4 ,they serve to give us a    
diffused light which enables us to see  
clearly all visible objects4 ,we have   
all noticed the effect of a single      
electric arc light1 situated at a       

distance from any other source of light1
 and how it casts extremely dark shadows
 and very high lights2 so much so that  
it is difficult to see an object        
perfectly in this light1 because the    
part of an object that is under the     
direct rays of the lamp is so highly    
illuminated that the shadow1 by         
comparison1 has the effect of simply a  
dark blot without form or shape4 ,many  
of you have noticed in a country        
village1 where the streets are lighted  
with electric arc lamps1 what a         
difference there is in the illuminating 
effect between a clear and a foggy      
night4 ,when there is a fog1 or when the
 clouds hang low down1 we get a         
reflection from these which tends to    
diffuse and soften the powerful light   
rays that are sent out by these lamps4  
,this effect is especially noticeable   
when the night is only moderately foggy4
 ,each globule of moisture floating in  
the air becomes a reflector of light1   
and by myriads of reflections and       

counter reflections the light 7which on 
a clear night is concentrated7 is       
diffused over a large area1 producing an
 illumination which for practical       
purposes is far superior to that        
produced on a clear night4 ,when the    
latter condition prevails the rays of   
light are so intense on objects         
immediately surrounding the lamps that  
one is blinded2 so that the places which
 are in shadow seem darker than they    
would be if there were no light at all4 
,the only way to prevent this effect is 
to have the lights so close together    
that there will be cross lights1 which  
tend to break up the intensity of the   
shadows4 ,this principle of light       
diffusion is taken advantage of to      
produce an even illumination in stores  
that are lighted only on one or two     
sides4 ,this is effected by a series of 
prisms or reflecting surfaces that are  
cast upon the panes of glass4  ,if now  
there were no atmosphere--or1 to state  
it differently--if there were no        

floating substances in the atmosphere1  
the sun would produce an effect upon the
 earth similar to that of a single      
electric light4 ,the lights would be    
extremely high1 and the shadows         
extremely dense4 ,to one looking off    
into space1 the sky1 instead of having  
the blue appearance that we see1 would  
have the effect of looking into a deep1 
dark abyss without illumination4        
,tyndall has shown us by a beautiful    
experiment that if there be in a glass  
tube a mixture of gases related to each 
other in a certain way chemically1 they 
will combine into small globules or     
particles similar to moisture in the    
air4 ,if now a beam of light is thrown  
upon this tube and a dark screen put    
behind it1 we shall1 in the beginning of
 the experiment1 simply see the dark    
screen4 ,as soon1 however1 as the       
molecules of the gases have combined in 
sufficient numbers to produce particles 
of sensible size we begin to have a     
reflection of light from them1 the color

 of which is constantly changing as the 
combining particles grow in size4 ,at a 
certain stage in its progress the color 
which the mixture of gases assumes is a 
beautiful azure blue1 rivaling in purity
 the finest skies of ,greece or southern
 ,italy4  ,the sun is the great lamp    
that illuminates the world1 while the   
atmosphere1 which is filled with        
particles of various substances1 becomes
 the shade of the lamp which diffuses   
and softens the light and gives it its  
color tones1 whether of warmth or       
coldness4 ,we could not well do without 
the reflected light of the sky4 ,the    
poetry of life would be sadly marred4   
,the beautiful effects of color and     
purity of tone would be wanting4 ,we    
need to bathe in light as much as in    
water1 and the character of the light is
 almost as important as the character of
 the water4 ,imagine a world with an    
atmosphere devoid of all substances that
 would in any way reflect light or give 
to it softness or color tone4 ,imagine a

 sun or a moon without visible rays--for
 without a reflecting atmosphere there  
would be none4 ,imagine a sky that was  
no sky at all1 but only a dark void1    
with no protecting vault4 ,think of the 
shadows1 so dark that you could see     
nothing in them4 ,these would be some of
 the effects that would come from an    
atmosphere that had no sky substance in 
it4 ,imagine the world lighted by one   
great arc light4 ,the reflex action upon
 the race living in such a light would  
be anything but desirable4 ,the world   
would develop into an arc-light         
civilization--if one can imagine what   
that would be like2 certainly one of    
intensely violent contrasts4 ,look on   
this picture and let us be thankful for 
the blue sky and golden sunsets4  ,but1 
you ask1 why is the sky blue8  ,in one  
of the chapters on the subject of light 
in ,vol4 ,,ii4 the properties of soap   
bubbles are discussed4 ,it is shown that
 when a film is stretched across the    
mouth of a tumbler held in a position so

 that the film is perpendicular1 by the 
action of gravity 7the moisture         
constantly falling to the lower part of 
the film7 it will continually grow      
thinner1 and horizontal bands of color  
will appear upon it1--first red1 then   
followed by the other colors of the     
solar spectrum1 ending with violet4  ,it
 is also stated that every color of     
light has a definite wave length4 ,where
 a band of blue color appears upon the  
film we know that its thickness is right
 for the wave length of that particular 
color which is reflected from the back  
of the film to the eye4 ,if we could    
conceive the blue vault of the heavens  
to be half a sphere of a soap bubble1   
the color that the sky would appear to  
us 7if the light could be thrown upon it
 from beneath7 would be determined by   
the thickness of this film4 ,if the film
 was #a-aef1jjj of an inch the sky would
 be red instead of blue4 ,to reflect the
 other colors the film would have to    
grow thinner for each color1 in the     

progression from red to violet4 ,the    
color of the sky is determined by a     
light-reflection from minute globules of
 moisture floating in the air4 ,if the  
sky is blue1 then the globules must be  
of the right diameter to reflect that   
color4 ,the various tints and colorings 
of the sky are determined by what is    
found in the atmosphere1 and this is the
 reason why skies differ in coloring and
 tone in different sections of the      
globe4 ,the finest skies are probably   
found in semi-tropical regions like     
southern ,italy1 ,greece1 and           
,california4  ,in #ahib ,i visited      
,greece in the early part of ,june4 ,in 
crossing the ,adriatic1 from ,brindisi  
to ,patras in ,greece1 the route was    
through the ,ionian ,islands that are   
grouped along the southwestern shore of 
,albania4 ,the sky was without a cloud1 
and its beautiful blue color was        
reflected in the waters of the          
,adriatic1 and ,i never shall forget the
 impression made upon my senses when we 

first came in sight of the mountains on 
the west coast of ,albania4 ,at this    
point they rise abruptly from the water 
and are colored with that peculiar azure
 haze1 mixed with a shading of warmth1  
which is an effect that distance gives  
in the classic atmosphere of old        
,greece4 ,the effect upon the beholder  
is to intoxicate the senses and to fill 
him with that deliciously poetic feeling
 that always comes when standing in the 
presence of the sublime in nature4 ,it  
was not the mountains themselves that   
produced the effect1 for ,i had seen    
grander than these2 but it was the sky  
on the mountains4 ,when we look at a    
distant mountain it seems to be partly  
hidden by a peculiar haze that is the   
color of the sky at that time2 we are   
really looking at the mountain through a
 portion of the sky4 ,while in ,athens  
,i took a trip to the top of ,mount     
,pentelicus1 which separates the plains 
of ,athens on the south from those of   
,marathon on the north4 ,from the summit

 of this mountain we have a most        
wonderful view of the archipelago of the
 ,a,egean ,sea--a beautiful map of blue 
water and brown islands that melt       
together in the distance4 ,at our feet  
lay the historic plains of ,marathon1   
and in the distance rose the snow-capped
 peaks of ,mount ,olympus4 ,it is       
doubtful if the world furnishes a more  
beautiful combination of ocean1 island1 
continent1 and sky than can be seen from
 ,mount ,pentelicus4 ,myriads of brown  
islands set in the bluest of            
water--graceful in outline and multiform
 in shape--jutting headlands and        
land-locked harbors--strong in color and
 outline in the immediate foreground1   
but gradually melting together in the   
distance1 the brown becoming bluer and  
the blue a softer blue till the whole is
 lost on the horizon in a sky that      
shades back to the zenith in an         
ever-changing azure that for purity of  
tone baffles all description4  ,what    
wonder that a people born under such    

skies and whose eyes have feasted on    
such beauties in nature should conceive 
and execute such a masterful work of art
 as the ,parthenon6 ,while the variation
 of landscape1 the stretch of water     
filled with islands1 and the mountains  
capped with eternal snow were a         
prominent part of the picture1 it was   
the sky with its beautiful color-tones  
that after all gave it its wonderful    
charm4  ,the skies in a northern        
latitude are colder and grayer1 due to  
the fact that nearly always there is a  
certain degree of condensation of       
moisture existing1 which1 while it does 
not take the form of a cloud1 still     
gives a toning to the sky4  ,there is no
 doubt but that the color-tones of the  
sky have an influence upon the character
 and temperament of the people who live 
under them4 ,under semi-tropical skies  
the poetic nature is more strongly      
appealed to1 and a man is more likely to
 be controlled by his dreamy imaginings 
than his cold calculations4 ,we find    

this latter characteristic prevailing to
 a greater or less extent among the     
people who live under colder and sterner
 skies4 ,if all these qualities or      
influences could be combined in the     
right way1 the race would be stronger   
intellectually and in other ways4 ,it is
 always dangerous to a race of people to
 be developed along certain lines only4 
,the development should be symmetrical4 
,the strongest men are not those who are
 simply coldly intellectual1 neither    
those who are simply emotional and      
sentimental1 but those in whom heart1   
mind1 and soul are so related that each 
one of these elements re-enforces and   
strengthens the others4  ,at certain    
seasons of the year and in certain      
localities it is not uncommon to have   
wonderfully beautiful displays of       
coloring upon the skies and clouds at   
sunset4 ,the question is often asked why
 we do not see these displays at other  
times in the day than at sunrise and at 
sunset--for the same effects are seen in

 the morning1 but they are not noticed  
so often1 because to do so would        
interfere with the habits of the average
 man and woman4  ,the reason for this   
change of coloring is the angle at which
 the sun's rays strike the clouds of an 
evening sky1 which are reflected to our 
eyes4 ,when the sun is high in the      
heavens it shines against the back of   
the clouds1 from the point of view of a 
person standing on the surface of the   
earth4 ,it also shines a shorter        
distance through the air at midday than 
at sunset4 ,at sunset the rays are able 
to shine on the under side of a cloud1  
especially if it is high in the air4    
,the moisture globules of which the     
cloud is made up are much larger than   
the transparent ones that are           
uncondensed and just as they were when  
released in the process of evaporation4 
,as we have already seen1 the           
reflections from these minute globules  
give us the blue coloring of the sky and
 are very much smaller in diameter than 

a globule that is able to reflect the   
red ray4 ,when these small globules are 
condensed into cloud a great number are 
combined into one globule1 and they are 
of all sizes1 from the globule of       
evaporation to that of the raindrop when
 precipitation takes place4 ,we have1   
then1 in the various stages of cloud    
formation all conditions present for    
reflecting the various colors and       
combinations of colors that are found in
 the solar spectrum4 ,hence it is that1 
under certain conditions of atmosphere  
and cloud formation1 we see at sunset   
painted upon the sky those wonderful    
combinations of colors1 more beautiful  
and delicate in shading1 more various in
 combination and purer of tone1 than any
 artist1 however cunning his fingers or 
brilliant his pigments1 has ever been   
able to truthfully reproduce4 ,even when
 the sky is cloudless it often assumes a
 brilliant hue1 which is partly a       
reflection from invisible moisture      
globules and partly due to floating     

particles of dust that may have been    
driven up from the surface of the earth1
 or may be the ashes of meteorites      
disintegrated by contact with the air4  
,some years ago1 commencing in ,august1 
#ahhc1 there was a wonderful exhibition 
of red skies at sunset that lasted for  
several hours after twilight ordinarily 
disappears4 ,this phenomenon ran through
 a period of several weeks1 gradually   
fading away4 ,it was afterward          
determined that these displays were     
occasioned by small particles of ashes  
or dust floating high in the air1 that  
were thrown off from the volcanic       
eruption of ,krakatoa in the ,island of 
,java4 ,by the general circulation of   
the air the ashes were carried to all   
parts of the world1 making a circuit of 
the earth in from twelve to thirteen    
days--which showed a velocity of over   
eighty miles an hour4 ,this is an       
instance of the high velocity of the air
 currents in the upper regions of the   
atmosphere4 ,the reason why the         

illumination extended so late in the    
night was because of the great height   
that these particles of dust attained4  
,the higher the reflecting surfaces are 
in the air the longer they may be seen  
after sunset4 ,ordinary twilight is     
caused by a reflection of sunlight from 
the upper air2 and from its duration as 
ordinarily observed it is estimated that
 the reflection does not proceed from a 
point more than thirty-six miles high4  
,in the higher latitudes the twilight is
 long1 from the fact that the sun does  
not go directly down1 and if we go far  
enough north the whole night is         
twilight4 ,in the tropical regions the  
twilight is shorter than at any other   
point on the globe for reasons that are 
obvious4 ,the sun there goes directly   
down and is soon hidden behind the      
earth4  ,there are other optical effects
 to be seen sometimes on the horizon    
somewhat resembling twilight4 ,the      
aurora borealis 7northern lights71 which
 we describe in ,vol4 ,,iii41 is seen in

 the northern skies at certain times1   
and has very much the appearance of     
twilight in some of its phases4 ,it is  
constantly changing1 however1 and is    
easily distinguished by anyone who has  
observed both4 ,these appearances are   
undoubtedly electrical4 ,there is       
another phenomenon seen in the arctic   
regions that causes a band of white     
light to appear on the horizon called   
ice blink1 and it is caused by the      
reflections from the great icebergs that
 abound in that region4  ,curious       
optical effects are sometimes observed a
 little after sunset in the form of     
streamers or bands of light that shoot  
up into the sky1 sometimes to a great   
height4 ,these are undoubtedly due to   
cloud obstructions that partially shut  
off the sun's rays from a part of the   
sky1 but allow it to shine with greater 
brilliancy in the path of these bands of
 light4  ,it will be seen from the      
foregoing that the sky in all of its    
phases is a product of sunlight and the 

substances that float in the air1       
including moisture1 not only in the     
invisible state1 but in all the stages  
of condensation1 as well as particles of
 floating dust4     ,,chapter ,,xviii4  
,,liquid ,,air4   ,air1 like water1     
assumes the liquid form at a certain    
temperature4 ,water boils and vaporizes 
at #bab degrees ,fahrenheit above zero1 
while liquid air boils and vaporizes at 
#cab degrees below zero4  ,heat and cold
 are practically relative terms1        
although scientists talk about an       
absolute zero 7the point of no heat71   
and ,professor ,dewar fixes this point  
at #dfa degrees ,fahrenheit below zero4 
,others have estimated that the force of
 the moon during its long night of half 
a month1 is reduced in temperature to   
six or seven hundred degrees below1     
which is far lower than ,professor      
,dewar's absolute zero4 ,however this   
may be1 to an animal that is designed to
 live in a temperature of #gj or #hj    
degrees ,fahrenheit1 any temperature    

below zero would seem very cold4 ,if1   
however1 we were adapted to a climate   
where the normal temperature was #cab   
degrees ,fahrenheit below zero1 we      
should be severely burned if we should  
sit down upon a cake of ice4 ,such a    
climate would be impossible for animal  
existence1 for the reason that there    
would be no air to breathe1 since it    
would all liquefy4  ,liquid air is not a
 natural product4 ,there is no place on 
our earth cold enough to produce it4 ,if
 the moon had an atmosphere 7which it   
probably has not7 it would liquefy      
during the long lunar night1 for heat   
radiates very rapidly from a planet when
 the sun's rays are withdrawn from it4  
,as you have already surmised1 liquid   
air is a product of intense cold4 ,any  
method that will reduce the temperature 
of the air to #cab degrees ,fahrenheit  
below zero will liquefy it4 ,great      
pressure will not do this1 for we may   
compress air in a strong vessel until   
the pressure on every square inch of the

 vessel is #ab1jjj pounds1 or six tons1 
and still it will not liquefy unless the
 temperature is brought down to the     
required degree of coldness4 ,if this is
 done it will change from a gas to a    
liquid1 but will occupy as much space as
 before1 if it is condensed to a        
pressure of six tons to the square inch4
  ,until twenty years ago it was        
supposed that oxygen and atmospheric air
 7the latter a mixture of oxygen and    
nitrogen7 were fixed gases and could not
 be liquefied4 ,in #ahgg1 it is said    
that ,raoul ,pictet obtained the first  
liquid oxygen1 but only a few drops4    
,about fifteen years later ,professor   
,dewar of the ,royal ,institution1      
,london1 succeeded in liquefying not    
only oxygen but atmospheric air4 ,and   
besides liquefying the air he made ice  
of it4  ,in #ahib ,i visited ,london1   
where ,i met ,professor ,dewar1 who     
invited me to witness an exhibition of  
the manufacture of liquid oxygen--and   
incidentally liquid air--at the ,royal  

,institution4 ,to me it was a most      
wonderfully interesting event4 ,i saw   
air1 taken from the room1 gradually     
liquefy in a small glass test tube open 
at the top4 ,when the tube was withdrawn
 from the refrigerating chamber it      
boiled by the heat of the room1 and     
rapidly evaporated4 ,we lighted a       
splinter of wood and blew it out1       
leaving a live spark on the end of it1  
and held it over the mouth of the tube1 
knowing that if anything like pure      
oxygen were evaporating the splinter    
would relight and blaze 7an old         
experiment with oxygen gas74 ,at first  
the splinter would not relight1 because 
the evaporating gases were a mixture of 
oxygen and nitrogen in the proportions  
to form air4 ,but owing to the fact that
 nitrogen evaporates sooner than oxygen1
 a second trial was successful1 for the 
splinter immediately began to blaze1    
showing that the gas evaporating then   
was pure1 or nearly pure1 oxygen4  ,when
 the liquid oxygen was poured into a    

saucer and brought into proximity with  
the poles of a powerful magnet the      
liquid immediately rushed out of the    
saucer and clung to the magnet poles2   
showing that oxygen is magnetic4  ,since
 that time other experimenters have     
succeeded in making liquid air on a     
comparatively large scale1 and the      
process is simple when we consider some 
of the old methods4  ,mr4 ,tripler of   
,new ,york1 who has made liquid air in  
great quantities1 does it substantially 
as follows3 ,first1 he compresses air to
 about #bejj pounds to the square inch4 
,of course the air is very hot when it  
is first compressed because all the air 
in the tank has been reduced in bulk    
about #aff times1 and all the heat that 
was in the whole bulk of air is         
concentrated into one-#affth of the     
space it occupied before it was         
compressed4 ,it is #aff times hotter4   
,there are two sets of pipes running    
from the compressor to a long upright   
tank called the liquefier4 ,these pipes 

pass through running water1 so that the 
compressed air is quickly cooled down to
 the temperature of the water 7about #ej
 degrees ,fahrenheit74 ,the pipes--at   
least one set of them--run the whole    
length of the liquefier1 and most likely
 are coiled4 ,this set of pipes contains
 the air to be liquefied4 ,a second set 
of pipes runs to the bottom of the      
liquefier1 where there is a valve4 ,by  
opening this valve a jet of compressed  
air is allowed to play on the other set 
of pipes1 when intense cold is produced 
by the sudden expansion of the air4     
,this cold air rushes up around the pipe
 containing the air to be liquefied and 
escapes at the top1 thus absorbing the  
heat until the temperature is reduced to
 #cab degrees below zero4 ,then the air 
liquefies and runs into a receptacle1   
where it may be drawn off at pleasure4  
,it will be seen that a large part of   
the compressed air is wasted in cooling 
the remainder sufficiently to liquefy4  
,the use to which liquid air may be put1

 advantageously1 is an unsolved problem2
 but no doubt it will have a place in   
time4 ,all great discoveries do4        
,electricity had to wait a long time for
 recognition2 but what a part it plays  
now in the everyday life of the whole   
civilized world6  ,curious effects are  
produced by this intense cold4 ,meat may
 be frozen so hard that it will give off
 a musical tone when struck4 ,here is a 
pointer for the seeker of novelties in  
the line of musical instruments4        
,liquid air furnishes a beautiful       
illustration of the fact that a burning 
gas jet is continually forming water as 
well as giving out heat and light4 ,if  
we put liquid air into a tea kettle and 
hold it over a gas jet1 ice will form on
 the bottom from the water created by   
the flame1 and it will freeze so hard   
that the flame will make no impression  
upon it1 other than to make the ice cake
 grow larger4  ,although liquid air is  
not found in nature1 and is therefore   
called an artificial product1 it is     

produced by taking advantage of natural 
law4 ,without the intellect of man it   
never would have been seen upon this    
earth2 and the same may be said         
concerning many things in our world1    
both animate and inanimate4 ,the genius 
of man is ,god-like4 ,he lifts the veil 
that shrouds the mysteries of nature1   
and here he comes in very touch with the
 mind of the ,infinite4 ,man interprets 
this thought through the medium of      
natural law1 and lo1 a new product6     
,how much life would have been robbed of
 its charm and interest if all these    
things had been worked out for us from  
the beginning6 ,for there is no interest
 so absorbing and no pleasure so keen as
 that of pursuit when the pursuer is    
reaching out after the hidden things    
that are locked up in ,nature's great   
storehouse4 ,from time to time she      
yields up her secrets1 little by little1
 to encourage those who love her and are
 willing to work1 not only for the      
pleasure of the getting1 but for the    

highest and best good of their fellows4 
,,water4     ,,chapter ,,xix4  ,,rivers 
,,and ,,floods4   ,water covers such a  
large proportion of the earth's surface 
and is such an important factor in the  
economy of nature that it becomes a     
matter of interest to study the process 
of its distribution4 ,water is to our   
globe what blood is to our bodies4 ,a   
constant circulation must be kept up or 
all animal and vegetable life would     
suffer4 ,here1 as in every other        
operation of nature1 the sun is the     
great heart and motive power that is    
active in the distribution of moisture  
over the face of the globe4  ,the total 
annual rainfall on the whole surface of 
the earth amounts to about #bh1jjj cubic
 miles of water4 ,only about one-fourth 
of this amount ever reaches the ocean1  
but it is either absorbed for a time by 
animal and vegetable life or lifted     
through the process of evaporation into 
the air as invisible moisture1 when it  
is carried over the region of rainfall  

and there condensed into water and falls
 back upon the earth--only to go through
 the same operation again4 ,the whole   
surface of the earth is divided into    
drainage areas that lead either directly
 through rivulets and rivers to the     
ocean1 or into some land-locked basin1  
where it either finds an outlet under   
ground or is kept within bounds through 
the process of evaporation1 the same as 
is the case with our great oceans4 ,in  
,north ,america the amount of drainage  
area that has no outlet to the ocean    
amounts to about #c per cent4 of the    
whole surface4 ,in other countries the  
percentage of inland drainage is much   
larger4 ,the great ,salt ,lake in ,utah 
is an instance where there is no outlet 
for the water except through the medium 
of evaporation4 ,inasmuch as all rivers 
and streams contain a certain proportion
 of salt1--especially in such strongly  
alkaline land regions as the ,great     
,basin of the ,north ,american          
continent1--these inland lakes in time  

become saturated with this and other    
mineral substances4  ,salt is constantly
 being carried into the lake by the     
water of the stream that feeds it1 and  
the water is continually being          
evaporated1 leaving the salt behind4    
,this process has been going on in the  
valley of ,utah for so long a period    
that #ag per cent4 of the contents of   
the lake is salt4 ,the ,humboldt ,river 
in ,nevada1 which empties into a small  
lake of the same name1 and lies at the  
foot of the ,humboldt ,mountains1 is    
said to have an underground outlet4     
,this must be the case1 because the area
 of the lake is very small as compared  
with ,salt ,lake1 while the river that  
feeds the latter is very small compared 
with the one that flows into the former4
 ,that is to say1 in the one case a very
 small stream empties into a large lake1
 while in the other case a much larger  
stream feeds a very small lake4         
,besides1 ,humboldt ,lake1 unlike the   
,great ,salt ,lake1 is said to be a     

fresh-water lake2 if it had no outlet it
 would become in time saturated with    
salt4 ,the largest body of water in the 
world having no outlet to the ocean is  
the ,caspian ,sea1 on the border between
 ,asia and ,russia in ,europe1 it being 
#ahj1jjj square miles in extent4  ,where
 rivers empty into large bodies of      
water1 such as the great chain of lakes 
on the northern border of the ,united   
,states 7and these lakes have an outlet 
connecting one with the other1 and      
finally by a river to the ocean7 a      
constant circulation is being kept up1  
and the water remains fresh4 ,owing to  
the fact1 however1 of the great         
evaporating surface that these lakes    
afford1 there is a greater disproportion
 between the rainfall upon the drainage 
area tributary to these lakes1 and the  
amount of discharge through the ,st4    
,lawrence ,river1 than would be the case
 with a river that was not connected    
with a system of lakes4 ,the amount of  
rainfall upon the area drained by the   

,mississippi ,river during one year     
amounts to about #fad cubic miles of    
water1 while the discharge at the mouth 
of the ,mississippi ,river is only about
 #aed cubic miles4 ,the difference      
between the two figures has been carried
 up by the process of evaporation or    
stored in vegetation4 ,these figures    
vary considerably1 however1 with        
different years4  ,the proportion of    
rainfall to discharge will vary greatly 
in different rivers from other causes   
than having a large evaporating surface4
 ,this variation is due to the          
difference in the ability of the soil to
 retain water after a rainfall4 ,in some
 drainage areas the ground is more or   
less impermeable to water1 and in this  
case the water runs readily off1 causing
 a sudden rise in the river2 and as     
suddenly it reaches the low-water mark4 
,in other drainage areas the ground is  
very permeable to water1 so that the    
rain penetrates to a greater depth into 
the earth1 where it is held1 and by a   

slow process drains into the rivers1    
while much more of it is carried off by 
evaporation and into vegetation than is 
the case in the drainage district before
 mentioned4  ,the courses of rivers are 
determined by the topography of the     
country through which they flow4 ,the   
sinuous windings1 that are found to be a
 characteristic of nearly all rivers1   
are caused by the water1 through the    
force of gravity1 seeking the lowest    
level1 and avoiding obstructions1 which 
they can flow around more easily than   
remove4  ,great rivers often change     
their courses1 especially where they    
flow through a region of made earth1    
such as is the case with the lower      
,mississippi ,river1 and in other great 
rivers of the world4 ,the loose earth is
 continually shifted by the current1 and
 where the current is not very strong it
 will often hold the water back to such 
an extent of accumulated weight that the
 flood will break over at some weak     
point on its banks and make a new course

 for itself4  ,one of the great rivers  
of ,china--the ,hwangho--often causes   
dire destruction to life and property   
owing to change in its bed from time to 
time4 ,it is estimated that between the 
years of #ahea-ff this river caused the 
loss of from #cj1jjj1jjj to #dj1jjj1jjj 
lives through drowning and famine by the
 destruction of crops4  ,floods in      
rivers are occasioned from various      
causes4 ,of course the primary cause is 
the same in all cases1 that is1 from    
precipitation of moisture in the form of
 rain or snow4 ,some rivers are so      
related to the area of rainfall and to  
the permeability of the soil that there 
is but little variation in the amount of
 discharge throughout the year4 ,the    
great river of ,south ,america1 the     
,amazon1 is an instance of a river of   
this class4 ,a certain number of the    
smaller rivers that feed it lie in the  
area of rainfall during the whole of the
 year2 for instance1 the streams of the 
upper ,amazon are being fed by rains at 

one season of the year1 when those      
feeding the river lower down are at the 
lowest stage4 ,when the rainy season    
prevails in the upper section of the    
river the dry season prevails farther   
down1 while at another season of the    
year these conditions are reversed4     
,therefore1 though the ,amazon has a    
larger drainage basin than any other    
river in the world1 and in some parts   
the yearly rainfall is #bhj inches1     
there is no very great fluctuation in   
the stages of water4 ,the ,orinoco      
,river1 which flows through ,venezuela1 
and whose drainage area is largely      
covered with mountains1 has a greater   
fluctuation than any other river1 the   
difference between high and low water   
amounting to seventy feet4  ,the ,river 
,nile has an annual rise of from        
fourteen to twenty-six feet4 ,this river
 is the sole dependence of the          
inhabitants of lower ,egypt1 and their  
sustenance depends upon the height to   
which the river rises2 if it does not   

rise high enough the agricultural lands 
are not sufficiently irrigated1 and if  
it rises too high their crops are       
destroyed by the floods4 ,in this       
section they depend entirely upon the   
overflow of the ,nile for irrigation1   
and not upon the rainfall4 ,there is    
scarcely ever a rainfall in lower ,egypt
 except about once a year on the coast  
of the ,mediterranean4 ,after ascending 
the river for a short distance we come  
into an area of no rain for a distance  
of #aejj miles along the river4 ,egypt  
has a superficial area of about #aae1bjj
 square miles1 and only about           
one-twelfth of this area is in a        
position to be cultivated4  ,as there is
 no rainfall in this region1 the sole   
dependence for agricultural purposes is 
from the ,river ,nile when it rises to a
 sufficient height to admit of          
irrigation4 ,the river brings down      
quantities of rich earth which during   
the overflow is deposited1 and thus the 
agricultural regions are refertilized   

annually4  ,the ,river ,nile is what is 
called a tropical river and is fed by   
the rains in upper ,egypt caused by the 
monsoon winds that prevail in that      
section of ,africa during the summer    
season1 as they do in ,india4 ,as has   
been explained in a former chapter1 the 
monsoon winds blow steadily for about   
six months from off the southern ocean4 
,these winds are highly charged with    
moisture1 which is not precipitated till
 it strikes the mountainous regions of  
the interior4 ,here the high mountains1 
which are often snow-capped1 cause a    
profuse precipitation1 which runs off   
into the various feeders of the ,nile1  
causing a gradual rise in the river that
 reaches the highest point about        
,september of each year4 ,if the ,nile  
should dry up1 or if the annual floods  
should materially change in height1 it  
would make a desert region of all that  
portion of ,egypt now so productive4    
,the great rivers of ,china1 the        
,yang-tse-,kiang and the ,hwangho1 are  

also tropical rivers and have an annual 
flood4 ,sometimes the rise is as much as
 fifty-six feet4 ,these annual floods   
are also caused by the monsoon winds    
that carry moisture from the ocean1     
which is condensed and precipitated in  
the mountains of central ,asia4 ,the    
conditions are substantially the same as
 those which prevail at the sources of  
the ,nile in ,africa4  ,rivers are      
produced from all sorts of causes1 some 
of them flowing only during the rainy   
season1 while others are fed by melting 
snow from the higher mountains1 and as  
the snow is rarely melted away entirely 
during the summer1 in the high          
mountains1 there is a continual flow    
from this source4 ,the snow forms a     
system of storage1 so that the water is 
held back and is gradually given up as  
it melts4 ,if this were not true        
mountainous regions would be subjected  
to disastrous floods4 ,if the           
precipitation were always in the form of
 rain it would immediately run off      

instead of being distributed over a     
whole season4 ,the ,platte is an        
instance of a river largely fed by the  
melting snows--of the ,rocky ,mountains4
  ,in the region of glaciers in the     
mountains of ,alaska and ,switzerland   
rivers are fed by the melting ice4      
,these rivers are usually of a milky    
color occasioned by the pulverization of
 rock caused by the grinding of the     
great glaciers as they flow down the    
gulches in the mountain side4 ,in some  
regions these glacial rivers have a     
diurnal variation4 ,this is caused by   
the fact that the glacier is so situated
 that it freezes at night1 which checks 
the flow1 and thaws in the daytime1     
which increases it4  ,rivers are to the 
globe what the veins are to the animal  
organization4 ,they pick up the surplus 
moisture not needed in the growth of    
vegetation and for the sustenance of    
animal life1 and carry it on1 together  
with the debris that it gathers in its  
course1 to the great reservoirs1 the    

seas and oceans1 where it is redistilled
 and purified by the action of the sun's
 rays4 ,from here it is carried back in 
the form of invisible moisture and again
 precipitated in the purified state1 to 
help carry on the great operations of   
growth--animal and vegetable4 ,the      
vaporized moisture that is carried back 
by the winds and redistributed          
corresponds to the blood1 after it has  
been purified and is carried back       
through the arteries to the extremities 
and capillary vessels which feed and    
nourish the bodily organs4     ,,chapter
 ,,xx4  ,,tides4   ,anyone who has spent
 a summer at the seashore has observed  
that the water level of the ocean       
changes twice in about twenty-four      
hours1 or perhaps it would be a better  
statement to say that it is continually 
changing and that twice in twenty-four  
hours there is a point when it reaches  
its highest level and another when it   
reaches its lowest4 ,it swings back and 
forth like a pendulum1 making a complete

 oscillation once in twelve hours4 ,when
 we come to study this phenomenon       
closely we find that it varies each day1
 and that for a certain period of time  
the water will reach a higher level each
 succeeding day until it culminates in a
 maximum height1 when it begins to      
gradually diminish from day to day until
 it has reached a minimum4 ,here it     
turns and goes over the same round      
again4 ,it will be further observed that
 the time occupied between one high tide
 and the next one is a trifle over      
twelve hours4 ,that is to say1 the two  
ebbs and flows that occur each day      
require a little more than twenty-four  
hours1 so that the tidal day is a little
 longer than the solar day4 ,it         
corresponds to what we call the lunar   
day4  ,as all know1 the moon goes       
through all its phases once in          
twenty-eight days4 ,the tide considered 
in its simplest aspect is a struggle on 
the part of the water to follow the     
moon4 ,there is a mutual attraction of  

gravitation between the earth and the   
moon4 ,because the water of the earth is
 mobile it tends to pile up at a point  
nearest the moon4 ,but the earth as a   
whole also moves toward the moon1 and   
more than the water does1 keeping its   
round shape1 while its movable water    
7practically enveloping it7 is piled up 
before it toward the moon and left      
accumulated behind it away from the     
moon4 ,so that in a rough way it is a   
solid sound earth1 surrounded by an oval
 body of water3 the long axis of the    
oval representing the high tides1 which1
 as they follow the moon1 slide         
completely around the earth once in     
every twenty-four hours4 ,thus1 there   
are really two high tides and two low   
tides moving around the earth at the    
same time2 and this accounts for the two
 daily tides4  ,we have accounted for   
the time when they occur in the fact    
that the water attempts to follow the   
moon1 but this does not account for the 
gradual changes in the amount of        

fluctuation from day to day4 ,the       
problem is complicated by the fact that 
the sun also has an attraction for the  
earth as well as the moon4 ,but from the
 fact that the sun is something like    
#djj times further from the earth than  
the moon is1 and also the fact that the 
attraction of one body for another      
varies inversely as the square of the   
distance1 the moon has an immense       
advantage over the sun1 although so much
 smaller4 ,if the power of the moon were
 entirely suspended1 or if the moon were
 blotted out of existence1 there would  
still be a tide4 ,the fluctuation       
between high and low tide would not be  
nearly so great as it is at present1 but
 it would occur at the same time each   
day1 because it would be wholly a       
product of the sun4  ,it will be easily 
seen that these two forces acting upon  
the water at the same time will cause a 
complicated condition in the movement of
 the waters of the ocean4 ,there will   
come a time once in twenty-eight days   

when the sun and the moon will act      
conjointly1 and both will pull in the   
same direction at the same time upon the
 water4 ,this joint action of the sun   
and moon produces the highest tide1     
which is called the spring tide4 ,from  
this point1 however1 the tides will grow
 less each day1 because the relation of 
the sun and moon is constantly changing1
 owing to the fact that it requires #cfe
 days for the sun to complete his       
apparent revolution around the earth1   
while the moon does her actual course in
 twenty-eight days4 ,when the sun and   
moon have changed their relative        
positions so that they are at right     
angles to each other with reference to  
the earth--at a quarter-circle          
apart--the sun and moon will be pulling 
against each other2 at least this is the
 point where the moon is at the greatest
 disadvantage with reference to its     
ability to attract the water4  ,because 
one-quarter around the earth the sun is 
creating his own tide1 which to that    

extent counteracts the effect produced  
by the moon1 the tide under the moon at 
this point is at its lowest point and is
 called the neap tide4 ,when the moon   
has passed on around the earth to a     
point where it is opposite to that of   
the sun--at a half-circle apart--there  
will be another spring tide1 and then   
another neap tide when it is on the last
 quarter1 and from that point the tide  
will increase daily until it reaches the
 point where the sun and moon are in    
exact line with reference to the earth's
 center1 when another spring tide       
occurs4 ,from this it will be seen that 
there are two spring tides and two neap 
tides in each twenty-eight days4 ,this  
is the fundamental law governing tides4 
,there are many other conditions that   
modify tidal effects4 ,neither the sun  
nor the moon is always at the same      
distance from the earth4 ,so that there 
will be a variation at times in high and
 low tides4 ,for instance1 it will      
happen sometimes that when both the sun 

and moon are acting conjointly they will
 both be at their nearest point to the  
earth1 and when this is the case the    
spring tide will be much higher than    
usual4  ,for many years the writer has  
observed that artesian wells1 made by   
deep borings of small diameter into the 
earth to a water supply1 have a daily   
period of ebb and flow1 as well as a    
neap and spring tide1 the same as the   
tides of the ocean1 except that the     
process is reversed4 ,the time of       
greatest flow of an artesian well will  
occur at low tide in the ocean4 ,this   
might be accounted for from the fact    
that when the tide is at its height the 
moon is also pulling upon the crust of  
the earth1 which would tend to take the 
pressure off the sand rock which lies   
one or two thousand feet below the      
surface and through which the flow of   
water comes1 and thus slacken the flow4 
,when the moon is in position for low   
tide1 the crust of the earth would      
settle back and thus produce a greater  

pressure upon the water-bearing rock4   
,this is the only theory that has       
suggested itself to the writer that     
would seem to account for these         
phenomena4  ,looked at from one         
standpoint1 it is easy to account for   
tidal action4 ,but when we attempt to   
make up a table giving the hour and     
minute as well as the height of the tide
 at that particular time we find that we
 have a very complicated mathematical   
problem4 ,however1 tables are made out  
so that we know at just what time in the
 day a tide will occur every day in the 
year4     ,,chapter ,,xxi4  ,,what ,,is 
,a ,,sponge8   ,before entering upon the
 great subject of water and ice--two of 
the most tremendous factors in          
world-building--let us consider a small 
matter1 so far as its permanent effects 
are concerned1 yet one which enters     
largely into the comfort and health of  
mankind1 and which1 though an animal1   
may be discussed where it belongs--under
 ,water4  ,there are few things more    

familiar about the ordinary household   
than a piece of sponge1 and yet1        
perhaps1 there are but few things about 
which there is so little known4 ,the    
sponge had been in use many1 many years 
before it was given a place in either   
the animal or vegetable kingdom4 ,the   
casual observer1 because he saw it      
attached to a rock1 jumped to the       
conclusion that it was of vegetable     
origin4 ,but after being kicked back and
 forth1 so to speak1 from one kingdom to
 the other1 even by what are called     
well-educated people1 it has finally    
been received into the family of        
animals2 a dignity in which the sponge  
itself seems to take but little         
interest4  ,the sponge is found in the  
bottom of the sea2 at no very great     
depth1 however4 ,it is usually attached 
to a rock or some other substance and it
 is due to this fact chiefly that it has
 been classed as a vegetable4 ,at least 
one scientist has attempted to give it a
 place between the two kingdoms1 but    

this only adds confusion without giving 
any satisfactory explanation of its     
origin4 ,it seems to belong to a very   
low order of animal life4 ,it breathes  
water instead of air1 but probably1 like
 many other water animals1 it absorbs   
the oxygen from the air which is more or
 less contained in the water4 ,there is 
a process of oxidation going on within  
the sponge in a manner somewhat as we   
find it in ordinary animal life1 and    
like the animal it expels carbon        
dioxide4 ,all this1 however1 is carried 
on apparently without any lungs or any  
digestive organs1 or in fact any of the 
organs that are common to the animals of
 the higher order4 ,the sponge1 however1
 as we see it in our bathrooms1 is only 
the framework1 bony structure1 or       
skeleton of the animal4  ,the sponge is 
exceedingly porous and readily absorbs  
water or any fluid by the well-known    
process of capillary attraction4 ,the   
sponge fiber is very tough and is not   
like anything known to exist in the     

vegetable kingdom4 ,the substance       
analyzes almost the same as ordinary    
silk1 which all know is an animal       
product4 ,if we burn a piece of sponge  
it exhibits very much the same phenomena
 as the burning of hair or wool1 and the
 smell is very much the same4  ,the     
structure of a piece of sponge when     
examined under a microscope is a        
wonderfully complicated fabric4 ,under  
the microscope it shows a network of    
interlacing filaments running in every  
direction in a system of curved lines   
intersecting and interlacing with each  
other in a manner to leave capillary    
openings4  ,it is a wonderful structure1
 and one that a mechanical engineer     
could get many valuable lessons from4   
,it will stand a strain in one direction
 as well as another4 ,there are no      
special laminations or lines of         
cleavage2 it is very resilient or       
elastic1 and readily yields to pressure1
 but as readily comes back to its normal
 position when the pressure is relieved4

 ,if we examine the body of a sponge we 
shall notice that there are occasional  
large openings into it1 but everywhere  
surrounded by smaller ones4 ,if we      
should capture a live sponge and place  
it in an aquarium with sea water1 where 
we could study it1 we should find a     
circulation constantly going on1 and    
that water was constantly sucked in at  
the smaller openings all over the       
outside of the sponge and as            
continuously ejected from the large     
openings4 ,this process constitutes what
 corresponds in the higher order of     
animals to both respiration and blood   
circulation1 combined4 ,the sponge feeds
 upon substances that are gathered up   
from the sea water1 and breathes the air
 contained in the same1 so that it      
breathes1 eats1 and drinks through the  
same set of organs4  ,when we first     
capture a live sponge from the sea it   
has a slimy1 dirty appearance1 and is   
very heavy4 ,the sponge is found to be  
filled with a glutinous substance that  

is the fleshy part of the animal4 ,it is
 very soft and jelly-like1 and after the
 sponge is dead it is readily squeezed  
out1 by a process which is called taking
 the milk out1 which leaves simply the  
skeleton1 the only useful part as an    
article of commerce4 ,this fleshy       
substance1 in life1 has somewhat the    
appearance and composition of the white 
of an egg4  ,the mechanical process by  
which the sponge takes its nourishment  
is exceedingly interesting4 ,there are  
small globe-shaped cells with openings  
through them that are lined with little 
hairlike projections that move in such a
 manner as to suck the water in at one  
side of the cell and push it out at the 
other4 ,these little fibers are         
technically called cilia4 ,we might     
describe them as little suction pumps   
that are located at many points in the  
sponge1 all acting conjointly to produce
 a circulation through the finer        
openings or capillary vessels and       
finally discharging into the larger     

chambers which carry off the residue4   
,if we should analyze the water as it is
 sucked into the sponge and that which  
issues from it through the larger       
openings1 we should find a difference   
between the two4 ,the expelled water    
would contain more or less carbon       
dioxide4  ,there are many different     
varieties of sponge1 and1 while they all
 possess certain characteristics in     
common1 they are still very different in
 many respects4 ,some of them are large 
and coarse1 while others are exceedingly
 soft and velvety4 ,what is called a    
single sponge is a colony of animals    
rather than a single animal2 at least   
they are so regarded by zooelogists4    
,this can hardly be true if we regard   
the sponge itself as a part of the      
animal4 ,if the sponge is simply        
regarded as the house in which the      
animal lives then it becomes a great    
tenement with numerous occupants4 ,but  
it is a tenement upon which the life of 
the sponge depends1 and is a part of it4

  ,the sponge could not breathe without 
the fibrous structure in the cells      
containing the machinery for producing  
the circulation4 ,it will be seen that  
the sponge1 while it is an animal1 is of
 the very simplest variety1 so far as   
its organs are concerned4 ,true1 its    
framework is very complicated1 but the  
organs for sustaining the life of the   
animal are the simplest possible4 ,the  
little self-acting pumps pull the water 
into the sponge through the smaller     
openings1 where it appropriates the food
 substance from the water and where a   
chemical action takes place which builds
 up the fleshy substance of the animal1 
and then expels the residue which is not
 needed to support its life4  ,simple as
 it is1 however1 as a mechanical        
structure1 the life and growth of the   
sponge is as mysterious as that of the  
most highly organized animal or even the
 soul of man4 ,we can study out the     
structure of a plant or animal2 we can  
analyze it and tell what are the        

elements of which it is composed2 we can
 describe the mechanical operations that
 are carried on and the chemical        
combinations that take place1 but no man
 has ever yet solved the mystery of     
life1 even in the lowest form--whether  
animal or vegetable4  ,the sponge1      
whether considered as a single or       
compound animal1 has the power to       
reproduce itself1 and here the mystery  
of life is as much hidden as it is in   
,god's highest creation4 ,it has been   
stated that every sponge contains a     
large number of separate cells which    
carry on the operation of circulation   
and respiration1 and may be likened to  
the heart and lungs of an animal of a   
higher creation4 ,zooelogists claim that
 each one of these cells represents a   
separate animal1 living in a common     
structure4 ,however this may be1 it is  
an interesting fact that the sponge has 
the power of secreting ova that grow in 
large numbers in little sacks until they
 have reached a certain stage of        

progress1 when they are expelled from   
the mother sponge and turned adrift in  
the great ocean to struggle for their   
own existence4 ,these eggs do not differ
 much in their structure and composition
 from an ordinary hen's egg1 except that
 there is no shell1 only a skin provided
 with little fibers called cilia1 that  
project from it1 and by the movement of 
these the embryo sponge is able to      
propel itself through the water4 ,it    
thus lives until it has reached a       
certain stage of development1 when it   
seeks out a pebble or rock1 to which it 
attaches itself at one end--preparation 
for which has been made by its peculiar 
structure during its life when it was   
free to float around through the water4 
,it is now a prisoner and chained to the
 rock it has selected for the foundation
 of its home4 ,having no longer any use 
for the little cilia1 which enabled it  
to swim through the water1 it now loses 
them4 ,here is a beautiful illustration 
of how nature provides for the          

necessities of the smallest things1 and 
how when the necessity that demanded a  
certain condition passes by the         
condition passes with it4 ,the embryo   
begins to show a fibrous development1   
which is the beginning of the framework 
of a new sponge4 ,evolution goes on1    
every step of which is as mysterious as 
a miracle1 until the growing thing is a 
full-grown sponge1 equipped with the    
means for respiration1 circulation1     
feeding1 digestion1 and reproduction4   
,sponges grow in the bottom of the sea  
at different depths4 ,they are obtained 
by divers who make a business of        
gathering them4 ,the best sponges are   
called the ,turkish sponge1 which are   
very soft and velvety1 and may be       
bleached until they are nearly white by 
subjecting them to the action of certain
 acids4 ,the divers become very expert1 
but they do not have the modern         
equipments of a diving suit4 ,the       
,syrian divers in the ,mediterranean go 
down naked with a rope attached to their

 waists and a stone attached to the rope
 to cause them to sink1 together with a 
bag for carrying the sponges4 ,they have
 trained themselves until they can      
remain under water from a minute to a   
minute and a half1 and in that time can 
gather from one to three dozen sponges4 
,the ordinary depth to which they       
descend is from eight to twelve fathoms4
 ,but a very expert diver will go down  
as far as forty fathoms4 ,the better    
class of sponges are said to grow in the
 deeper waters4 ,the coarse inferior    
sponges are called the ,bahama sponge4  
,this sponge is of a peculiar shape1    
growing more like a brush1 with long    
bristly fiber4  ,the trade in sponges is
 quite large4 ,the consumption in ,great
 ,britain alone amounts to about        
#a1jjj1jjj per annum4  ,the sponge as an
 animal possesses many advantages over  
his more aristocratic neighbor1 man4 ,he
 breathes but he has no lungs1 and      
therefore cannot have pneumonia4 ,he    
digests his food1 but he has no stomach1

 and therefore never has dyspepsia1     
gastritis1 or any of the many ailments  
that belong to that much abused organ4  
,he has no intestines1 and therefore    
cannot have appendicitis or ,asiatic    
cholera or any of the long train of     
diseases incident to those complicated  
organs4 ,he has no nervous system--oh1  
happy sponge6--therefore he cannot have 
nervous prostration1 hysteria1 or       
epilepsy4 ,he has no use for doctors1   
and therefore has no unpleasant         
discussions with his neighbors about the
 relative merits of the different       
schools of medicine4 ,if he has any     
predilections in the way of pathies we  
should say that he is a hydropath4      
,while he is a great drinker1 he is not 
at all convivial--he drinks only water1 
and takes that in solitary silence4 ,he 
sows all his wild oats when he is very  
young1 while he has the freedom to roam 
at will4 ,he soon tires of this1        
however1 for he selects the rock that is
 to be the foundation of his future home

 and there settles down for life1 wrapt 
in the solitude of his own originality4 
,he is not troubled with wars or rumors 
of wars4 ,his eyes are never startled or
 his nerves shaken by the scare         
headlines of yellow journalism4 ,the one
 sensation of his life1 if sensation he 
ever has1 is when a great ugly creature 
of some ,oriental clime comes down to   
his home and tears him away from his    
native rock1 carries him to the surface1
 and there literally squeezes the life  
out of him4 ,he finally dies of the     
grip1 and here he sinks to the level of 
his more aristocratic neighbor4  ,but   
there is another side to our philosophy4
 ,if the sponge is exempt from all these
 ills that we have enumerated it is     
because he is incapable of suffering and
 is therefore incapable of enjoyment4   
,those beings that have the ability to  
suffer most have also the ability to    
enjoy most4 ,the higher the type of     
civilization the greater possibilities  
it offers for real enjoyment--also for  

real misery4 ,this being true1 it should
 be the aim of highly civilized people  
to eliminate as far as possible those   
things that make for misery1 and        
cultivate those things that make for    
happiness in the highest and best sense4
     ,,chapter ,,xxii4  ,,water ,,and   
,,ice4   ,we now have entered upon a    
subject that is of intense interest1    
studied from the standpoint of facts as 
they exist to-day and of history as we  
read it in the rocks and bowlders that  
we find distributed over the face of the
 earth4  ,the whole northern part of the
 ,united ,states extending to a point   
south of ,cincinnati was at one time    
covered with a great ice-sheet1 traces  
of which are plainly visible to anyone  
who has made anything of a study of this
 subject4 ,the glaciers now to be seen  
in ,british ,columbia and ,alaska1 great
 as they seem to one viewing them       
to-day1 are by comparison with what once
 existed simply microscopic specks of   
ice4 ,glaciers1 like rivers1 flow by    

gravity1 following the lowest bed and   
lines of least resistance2 the          
difference being that in the one case   
the flow is rapid1 while in the other it
 is scarcely visible1 except by         
measurement from day to day4 ,before    
entering upon a description of the law  
that governs the flow of glaciers1 let  
us stop and give a little study to the  
phenomena of water as exhibited when it 
is at the freezing point4 ,water is such
 a large factor in the make-up of our   
globe and the air that surrounds it that
 it becomes a very interesting and      
important study to anyone who wishes to 
understand the phenomena of nature that 
are closely related to it4  ,as all     
know1 pure water is a compound of two   
gases1 oxygen and hydrogen1 combined in 
the proportion of two atoms of hydrogen 
and one of oxygen4  ,let us now study   
this fluid in its relation to heat4 ,the
 reader is referred to the chapters on  
heat in ,vol4 ,,ii41 where it is stated 
that heat is a mode of motion4 ,it is   

also stated that heat is a form of      
energy1 and that energy is              
indestructible1 that an unvarying amount
 of it exists in some form or another   
throughout the universe4 ,it is not     
always manifested as heat or            
electricity1 although both of these are 
always in evidence as active agents of  
force4 ,much of the energy is simply    
stored--all the time possessing the     
ability to do work or to be converted   
into any of its known forms1 such as    
heat1 light1 electricity1 or mechanical 
motion4 ,a weight that is wound up has  
required a certain amount of energy to  
elevate it to the position that it      
occupies4 ,while in its elevated        
position it possesses energy1 although  
not active4 ,energy in this form is     
called potential 7possible7 energy1 and 
has the power to do work if released4   
,active energy is called kinetic        
7moving7 energy1 and the sum of these   
two energies is a constant quantity4    
,we will now study energy as it is      

related to water in the form of heat4   
,there is a kind of heat called latent  
heat1 which is not heat at all1 but     
stored energy1 waiting to be turned into
 heat1 or light1 or some other active   
form4 ,properly speaking1 heat is a     
movement of the atoms of matter1 the    
intensity of which is measurable in     
degrees1 and called its temperature4 ,to
 use the term latent heat as meaning    
concealed heat1 which must reappear as  
heat1 is a misnomer and is very         
misleading4 ,if it is proper to call a  
wound-up spring or weight latent heat   
then its present use is a correct one4  
,what was formerly termed latent heat is
 simply a form of potential energy4     
,when sensible heat that is measurable1 
as temperature1 disappears in the       
performance of some sort of work1       
especially in connection with certain   
phenomena relating to water1 we call    
it--or rather miscall it--latent heat3  
but the phrase would better be stored   
energy4  ,the action of water under heat

 is very peculiar1 and in order to get a
 correct understanding of the phenomena 
exhibited in glacial action we also need
 to understand the phenomena of water at
 the freezing point4 ,as is well known1 
fresh water freezes at #cb degrees      
,fahrenheit1 and at the moment of       
freezing there is a sudden expansion to 
such an extent that a cubic foot of ice 
will occupy a much larger space than it 
will in the form of water2 and because  
it occupies so much larger space it is  
lighter than the same bulk of water     
would be1 and therefore it floats in    
water4  ,at the point of freezing1 the  
thermometer if placed on the ice will   
register #cb degrees4 ,if the ice is    
allowed to melt1 the water at the moment
 of liquefaction would be found to      
register the same degree of temperature 
as the ice when first frozen4 ,and yet  
there has been a vast expenditure of    
energy between the points of            
liquefaction and congelation1           
notwithstanding the temperature of ice  

may be lowered1 after it is formed1 many
 degrees1 which is measurable by the    
thermometer4 ,suppose we take a piece of
 ice which is #aj degrees below the     
freezing point and insert in it a       
thermometer4 ,if now we apply heat to   
this ice the thermometer will gradually 
rise until it reaches the melting point 
at #cb degrees ,fahrenheit1 where it    
will stand until all the ice is melted4 
,the application of heat is going on    
steadily1 but there are no indications  
of movement in the mercury until the    
last trace of ice with which it is in   
contact has been liquefied4 ,after the  
ice is all melted1 if the application of
 heat to the body of liquefied ice be   
continued1 the column of mercury will   
resume its movement upward until it     
reaches the boiling point1 where it is  
again arrested4 ,and no matter how much 
heat is applied to the boiling water1 if
 in an open vessel1 the thermometer     
remains the same until all the water is 
evaporated4 ,here are two curious facts1

 and they are facts that1 if we can     
master them1 will serve as a key to the 
understanding of much that is mysterious
 in nature4  ,it will be our endeavor to
 give the reader a mental picture of    
what is taking place during the time the
 ice is melting and the thermometer is  
stationary4 ,do not suppose that you can
 understand this1 even so far as it is  
understandable1 by a casual reading     
without thought4 ,no man was ever yet   
able to present a picture to the mind of
 another1 however clearly and simply it 
may be done1 unless that other mind is  
receptive4 ,when a photographer trains  
his camera upon an object1 however      
intense the light may be and however    
clean-cut the picture that is thrown    
upon the plate in the camera1 unless    
that plate is properly sensitized so    
that the picture may be impressed upon  
it1 all of the other conditions are in  
vain4 ,the reader is always a part of   
the book he is reading4     ,,chapter   
,,xxiii4  ,,stored ,,energy ,,in        

,,water4   ,in our last chapter we      
traced the upward movement in the       
mercury of the thermometer from #aj     
degrees below the freezing point up to  
the boiling point of water4 ,we found   
that the thermometer was arrested at #cb
 degrees and remained stationary at that
 point until all the ice was melted1    
notwithstanding the fact that heat was  
being constantly applied4 ,after the ice
 is all melted the mercury moves upward 
until it reaches the boiling point of   
water1 where the movement is again      
arrested1 and although the heat is being
 continuously applied1 it remains       
stationary until all the water is       
evaporated4 ,if we push the process     
still further1 with a sufficient        
application of energy we can separate   
the vapor molecules into their original 
elements1 oxygen and hydrogen4  ,let us 
go back now to the freezing point of    
water and see what is becoming of the   
heat that is consumed in melting the    
cake of ice1 and still does not produce 

any effect upon the mercury in the      
thermometer4 ,sensible heat1 as before  
stated1 is a movement of the atoms of   
matter1 and temperature1 as it affects  
the thermometer1 is a measure of the    
intensity of motion exhibited by these  
atoms4  ,in the experiment of the block 
of ice that in the beginning is #aj     
degrees below the freezing point1 as    
shown by the thermometer1 the molecules 
have a definite intensity of motion4    
,the intensity of this motion increases 
when heat is applied until it reaches   
#cb degrees1 when it remains stationary 
until all of the ice is melted4 ,at this
 point there is a rearrangement of the  
molecules of water as it assumes the    
liquid state4 ,to perform this          
rearrangement requires a certain amount 
of work done1 which is analogous to the 
winding up of a weight to a certain     
distance4 ,there has been energy used in
 winding up the weight1 but that energy 
now is not destroyed1 nor still in the  
form of heat1 but is in the potential   

state--ready to do some other kind of   
work4 ,so1 the heat that has been       
applied to the melting ice has been     
utilized during the process of its      
liquefaction in rearranging the water   
molecules and putting them in a state of
 strain1 so to speak1 like the weight   
that is wound up to a certain height4   
,there is a certain amount of potential 
energy that is stored in the molecules  
of water that will be given up and      
become active energy in the form of     
heat1 if the water is again frozen4 ,to 
melt a cubic foot of ice requires as    
much heat as it would to raise a cubic  
foot of water #add degrees ,fahrenheit4 
,but1 as we have seen1 while all of this
 energy is absorbed as heat1 it is not  
lost as energy4 ,it ceases to be kinetic
 or active and becomes potential energy4
 ,this 7let us repeat7 has been called  
latent heat4 ,the term grew out of the  
old idea that heat was a fluid and that 
when it became latent it hid itself away
 somewhere in the interatomic spaces of 

matter and ceased to be longer sensible 
heat4 ,it came into existence in the    
same manner and occupies the same place 
in the science of heat that the word    
current does in the science of          
electricity3 both of them are misnomers4
  ,when the ice is all melted potential 
energy is no longer stored1 but is      
manifested in the sensible heating of   
water1 the degree of which is measurable
 by the thermometer1 until it reaches   
the boiling point1 where it is again    
arrested4 ,all of the surplus heat above
 that temperature is consumed in rending
 the liquid water into moisture globules
 that float away into the air1 each one 
of them charged with a store of         
potential energy4 ,let us follow this   
vapor spherule as it floats into the    
upper regions of the atmosphere4        
,myriads of its fellows travel with it  
until it reaches a point where          
condensation takes place1 when it       
collapses and unites with other vapor   
particles to form water again4 ,in doing

 this the heat that was expended upon it
 to disengage it 7whether the heat was  
artificial or that of the sun's rays7   
now reappears either as sensible heat or
 as electricity1 or both4 ,and this is  
what is meant in meteorology by latent  
heat becoming sensible heat at the time 
of condensation2 in fact1 it is stored  
or potential energy becoming active or  
kinetic1 and assumes the form of heat or
 electricity1 as before stated4 ,we have
 thus reviewed the matter of the        
foregoing chapter in order to follow the
 course of the stored energy from the   
melting of the ice to the vapor1 and    
back again to water3 to doubly impress  
the fact that the energy used was not   
consumed1 but still exists and is ready 
for further work4  ,during the progress 
of a hailstorm1 it has been stated1 one 
of the factors that is active to produce
 this phenomenon is the intense         
ascensional force that is given to the  
moisture-laden air1 caused by intense   
heat at the surface of the earth4 ,this 

condition forces the moisture vapor to  
higher regions of the atmosphere than is
 the case with the ordinary             
thunderstorm4 ,another factor that is   
undoubtedly active in producing hail    
under these circumstances is that when  
condensation takes place in the higher  
regions1 and is therefore more energetic
 on account of the intenser cold1 the   
potential energy that is set free by the
 moisture spherules takes1 in a larger  
degree1 the form of electricity rather  
than heat1 as is the case under more    
ordinary circumstances4 ,while in the   
end this electrical energy becomes      
active heat1 it does not for the time   
being1 and thus favors the ready        
congelation of the condensed moisture   
into hailstones4 ,hailstorms are always 
attended by incessant thunder and       
lightning1 and this fact favors the     
theory advanced above4  ,it will be     
easily seen from a study of the         
foregoing what a wonderful factor       
evaporation 7which is a product of the  

sun's rays7 is1 in the play of celestial
 dynamics4 ,it ascends from the surface 
of the earth or ocean laden with a      
stored energy1 the power of which no man
 can compute1 and beside which          
gravitation is a mere point4 ,in the    
upper regions of atmosphere this        
potential force under certain conditions
 is released and becomes an active      
factor1 not only in the formation of    
cloud and the precipitation of rain1    
hail1 and snow1 but it disturbs the     
equilibrium of the air and sets that in 
motion4  ,certain physicists deny that  
evaporation has anything to do with     
atmospheric electricity4 ,they tell us  
that it is caused by the arrest of the  
energy of the sunbeam by the clouds and 
vapor in the upper atmosphere4 ,we admit
 that a part of the energy is so        
arrested1 and is stored1 for the time1  
in moisture globules by a process of    
cloud evaporation to transparent vapor  
again4 ,yet this does not hinder the    
same process from going on at the       

surface of the earth wherever there is  
water or moisture4 ,but they tell us    
that the electroscope does not show any 
signs of electrification in the         
evaporated moisture4 ,of course it does 
not4 ,the electroscope is not made to   
detect the presence of energy except    
when set free as electricity4  ,a       
wound-up spring does not seem to be     
electrified1 but if it is released the  
energy stored in it will be transformed 
into electricity if the conditions are  
right4 ,just so1 the energy required to 
put the moisture spherule into a state  
of strain is latent until some power    
releases it1 when it reappears as active
 energy of some form4  ,we have now     
followed the relation of heat to water  
from a point #aj degrees below freezing 
up to where it was forced into its      
original gases1 oxygen and hydrogen4    
,these gases have stored in them a      
wonderful amount of potential energy4   
,when one pound of hydrogen and eight   
pounds of oxygen unite to form water the

 mechanical value of the energy given up
 at that time in the form of heat is    
represented by #dg1jjj1jjj pounds raised
 to one foot in height4 ,and this is the
 measure of the energy that was put into
 nine pounds of water to force it from a
 state of vapor into its constituent    
gases4 ,after the combination of the    
gases into a state of vapor the         
temperature sinks to that of boiling    
water4 ,the amount of energy given up in
 condensing the nine pounds of vapor    
into nine pounds of water is equal to   
#f1gbj1jjj foot-pounds4 ,if this nine   
pounds of water is now cooled from the  
boiling point to #cb degrees ,fahrenheit
 we come to the final fall1 where the   
potential energy that is stored in the  
operation of melting ice is given up    
suddenly at the moment of freezing1     
which in nine pounds of water is        
#iic1edf foot pounds4  ,professor       
,tyndall1 in speaking of the amount of  
energy that is given up between the     
points where the constituent gases unite

 to form nine pounds of water and the   
point where it congeals as ice1 says3   
,our nine pounds of water1 at its origin
 and during its progress1 falls down    
three precipices--the first fall is     
equivalent in energy to the descent of a
 ton weight down a precipice #bb1cbj    
feet high-over four miles2 the second   
fall is equal to that of a ton down a   
precipice #bijj feet high1 and the third
 is equal to a fall of a ton down a     
precipice #dcc feet high4 ,i have seen  
the wild stone avalanches of the ,alps1 
which smoke and thunder down the        
declivities with a vehemence almost     
sufficient to stun the observer4 ,i have
 also seen snowflakes descending so     
softly as not to hurt the fragile       
spangles of which they are composed4    
,yet to produce from aqueous vapor a    
quantity which a child could carry of   
that tender material demands an exertion
 of energy competent to gather up the   
shattered blocks of the largest stone   
avalanche ,i have ever seen and pitch   

them to twice the height from which they
 fell4  ,when we contemplate the        
foregoing facts as related to so small  
an amount of water as nine pounds1 and  
multiply this result by the amount of   
snow- and rainfall each year and the    
amount of ice that is congealed and     
again liquefied by the power of the     
sun's rays1 we are appalled1 and shrink 
from the task of attempting to reduce   
the amount of energy expended in a      
single year to measurable units4        
,having considered water in its relation
 to heat in the preceding chapters1 we  
will now take up the subject of water in
 its relation to ice and snowfall and   
the phenomena exhibited in ice rivers1  
commonly called glaciers4  ,when water  
is under pressure the freezing point is 
reduced several degrees below #cb       
degrees ,fahrenheit4 ,this fact has been
 determined by confining water in a     
close vessel and putting it under       
pressure and subjecting it to a freezing
 mixture1 and by this means determining 

the freezing point under such           
conditions4 ,by putting a bullet or     
something of that nature into the water 
that is subjected to pressure one can   
tell by shaking it when the freezing    
point is reached4 ,if water is put under
 pressure and cooled to a point below   
#cb degrees1 and yet still remains in   
the liquid state1 it may be suddenly    
congealed by taking off the pressure2   
this shows that the pressure helps to   
hold the molecules in the position      
necessary for the liquid state1 and     
prevents the rearrangement of them that 
takes place at the moment of freezing4  
,when the water molecules are arranged  
for the liquid condition they may be    
compared to a spring that is wound up   
and held in position by the heat energy 
that is stored in the water4 ,and when  
this energy is given up to a certain    
degree the power that holds the spring  
wound up is suddenly released1 when it  
unwinds and occupies a larger space4    
,there is a force that we may call polar

 force1 which is constantly tending to  
push the molecules of water into an     
arrangement such as we see when         
crystallization takes place--as it      
always does in the act of freezing4     
,these polar forces cannot act so long  
as the energy in the form of heat is    
sufficient to hold the water in the     
fluid state4 ,but the moment this       
energy1 which tends to hold it in the   
fluid state1 falls below that which     
tends to rearrange it into the          
crystalline form1 it is overcome by the 
superior power of the latter force1 and 
we have the phenomenon of solidified    
water4  ,a very interesting experiment  
may be performed with a block of ice by 
anyone when the ice is near the melting 
point4 ,if a wire is put around the ice 
and a sufficient weight is suspended to 
it1 the pressure of the wire on the ice 
will gradually liquefy that portion     
immediately under the wire1 which allows
 it to sink into the ice slowly1 and as 
this process goes on the ice freezes    

together again behind the wire1 so that 
in time the wire will pass entirely     
through the block and leave it still a  
solid block1 as it was before the       
experiment began4  ,this is an          
interesting fact which it will be well  
to remember when we come to explain     
glacial action1 or rather the law that  
governs glacial action4 ,if we take two 
pieces of melting ice and bring them    
together they immediately congeal at the
 point of contact4 ,this phenomenon is  
called regelation4 ,ice has some of the 
properties of a viscous substance4 ,it  
will yield slowly to pressure1          
especially when near the melting point1 
but if put under a tensional strain it  
will break1 as any brittle substance    
will1 so that it has the properties of  
both viscosity and brittleness4         
,ordinarily we are in the habit of      
treating water as a fluid and ice as a  
solid1 but from what has gone before the
 reader must understand that in a       
certain sense ice should be treated as  

having semi-fluidic properties4         
,,chapter ,,xxiv4  ,,why ,,does ,,ice   
,,float8   ,nature is full of surprises4
 ,by a long series of experimental      
investigations you think you have       
established a law that is as unalterable
 as those of the ,medes and ,persians4  
,but once in a while you stumble upon   
phenomena that seem to contradict all   
that has gone before4  ,these1 however1 
may be only the exceptions that prove   
the rule4 ,it is recognized as a        
fundamental law that heat expands and   
cold contracts2 that the atom when in a 
state of intense motion 7which is the   
condition producing the effect that we  
call heat7 requires more room than when 
its motions are of a less amplitude4 ,in
 other words1 an increase in the        
amplitude of atomic motion is heating1  
while a decrease is cooling4 ,it follows
 from the above statement that the      
colder a body becomes the smaller will  
be its dimensions4 ,there are two or    
three1 and perhaps more1 exceptions to  

this rule1 and the most notable one is  
that of water4 ,water follows the same  
law that all other substances do under  
the action of heat and cold1 within     
certain limits only4 ,if we take water1 
say1 at #ej degrees ,fahrenheit and     
subject it to cold it will gradually    
contract in bulk until it reaches #ci   
degrees ,fahrenheit4 ,at this point1    
very curiously1 contraction ceases1 and 
here we find the maximum density of     
water4 ,if the temperature is still     
lowered we find the bulk is gradually   
increasing instead of diminishing 7as is
 the rule with other fluids71 and when  
it reaches the freezing point there is a
 sudden and marked expansion1 so much so
 that a cubic foot of ice1 which is     
solidified water1 will not weigh as much
 as a cubic foot of water before it     
freezes--hence it floats4  ,let us try  
an experiment4 ,take a small glass      
flask1 terminating in a long neck1 say  
of four to six inches1 and of small     
diameter4 ,suppose the water in the     

glass to be at #ej degrees ,fahrenheit4 
,fill the flask with water until it     
stands halfway up the neck at #ej       
degrees temperature4 ,now immerse the   
flask gradually in hot water1 and       
observe the effect4 ,for a moment the   
water will lower in the neck of the     
tube1 but this is due to the fact that  
the glass expands before the heat is    
communicated to the water and enlarges  
its capacity4 ,but immediately the water
 will begin to rise as the heat is      
communicated to it1 and will continue to
 expand up to the boiling point4 ,now   
take the flask out of the hot water and 
gradually introduce it into a freezing  
mixture made of broken ice and salt4    
,immediately the water will begin to    
fall in the tube1 showing that it is    
contracting under the cold1 and it will 
continue to contract until it reaches a 
temperature of #ci degrees ,fahrenheit1 
when it will come to a standstill and   
then proceed to expand as the           
temperature of the water lowers4 ,when  

it reaches the freezing point the fluid 
can no longer rise in the neck of the   
flask1 which is broken by the sudden    
expansion that takes place at this      
point4  ,to show what an irresistible   
power resides in the atoms of which the 
body is made1 let us take an iron flask 
with walls one-half inch or more in     
thickness2 fill it with water and seal  
it up by screwing on the neck an iron   
cap2 now plunge it into the freezing    
mixture1 and the first effect will be to
 contract the water unless it is already
 below #ci degrees ,fahrenheit1 but when
 it reaches that point expansion sets   
in1 which continues to the freezing     
point1 when a greatly increased         
expansion takes place suddenly4 ,the    
walls of the iron flask1 although a     
half-inch in thickness1 are no longer   
able to resist the combined efforts of  
the billions upon billions of the atoms 
of which the water is made up1 in their 
individual clamor for more room1 hence  
the flask is shivered into pieces4      

,there are one or two other substances  
which are exceptions to the general     
rule1 but we will mention only one1     
which is the metal bismuth4 ,if we      
should melt a sufficient amount to fill 
an iron flask1 such as we have          
described1 and subject it to the same   
freezing process1 the flask will be     
broken the same as in the experiment    
made with the water4  ,a query arises1  
,why this phenomenon8 ,why does water   
follow a different law in cooling from  
that of nearly all other substances8    
,this is a case where it is much easier 
to ask a question than to answer it4    
,when water solidifies at the moment of 
freezing1 crystallization sets in4 ,but 
what is crystallization8                
,crystallization is a peculiar          
arrangement of the molecules of matter1 
which takes place in some substances    
when they pass from the liquid to the   
solid form4 ,the molecules assume       
definite forms and shapes1 according to 
the nature of the substance4 ,when water

 assumes the solid form under the action
 of cold the molecules arrange          
themselves according to certain definite
 and fixed laws1 the result of which is 
to increase the bulk to a considerable  
extent over that which the same number  
of molecules would occupy at a          
temperature of #ci degrees ,fahrenheit4 
,hence1 as has been heretofore stated1 a
 given block of solidified water is     
lighter than the same bulk would be in  
the fluid state1 and this is the reason 
why ice floats4  ,what would happen in  
case nature did not make this exception 
to the laws of expansion and contraction
 by heat and cold1 in the case of water8
 ,first1 our lakes would freeze from the
 bottom upward2 as soon as the surface  
became frozen1 or even colder than the  
water underneath1 it would drop to the  
bottom1 the warmer water below coming up
 by a well-known law--that the warmer   
fluid rises and the colder falls4 ,this 
circulation would continue until ice    
began to form1 which would immediately  

drop to the bottom1 and this process    
would go on until the whole mass were   
frozen solid4 ,in the same way our      
rivers in the northern climates would   
freeze from the bottom1 and in time our 
valleys would fill up with ice to a     
thickness that the summer's sun would   
never melt1 and gradually all north of a
 certain zone would become a great      
glacier1 rendering not only the lakes   
and rivers but also the surface of the  
earth unfitted for animal life4  ,those 
who believe that the laws of nature are 
the creations of a beneficent and       
all-wise ,intelligence will see in this 
exception to the general law in the case
 of freezing water a striking evidence  
of design4 ,but those who have no such  
belief will say it is a most fortunate  
though fortuitous circumstance 7a saying
 they will have to make1 regarding      
thousands of other things in nature71   
and go on floundering in the            
interminable sea of ,i don't know4  ,the
 atom when it is acting under the       

direction of a fixed law is a giant in  
strength4 ,and when its individual      
strength is multiplied by billions upon 
billions the combined energy exerted    
produces a power that is irresistible4  
,not only has nature endowed these atoms
 with this wonderful power1 but she has 
also willed that they arrange themselves
 in lines of beauty4 ,in confirmation of
 this we need only to study the work of 
the frost upon our window panes4 ,as we 
lie in our beds on a cold night and     
exhale moisture from our lungs it       
settles upon the window panes of our    
bedrooms1 where ,nature--that wonderful 
artist--forms it into beautiful pictures
 that gladden our eyes when we awake3   
,most beautiful things2 there are       
flowers and trees1     ,and bevies of   
birds1 and swarms of bees1     ,and     
cities1 and temples1 and towers1 and    
these     ,all pictured in silver sheen4
     ,,chapter ,,xxv4  ,,glaciers4      
,glaciers are rivers of ice1 and1 like  
other rivers1 some of them are small and

 some very large4 ,they flow down the   
gorges from high mountains1 whose peaks 
are always covered with a blanket of    
eternal snow4 ,summer and winter the    
snow is precipitated upon these         
mountains1 and from time to time the    
heat of the sun's rays softens the snow1
 when by its great weight it packs more 
closely together until it is1 in many   
cases1 formed into solid ice-cakes4 ,if 
we take a quantity of snow or a quantity
 of granulated ice and put it under a   
sufficient pressure we can produce clear
 solid ice1 and it is by this process   
that ice is formed out of the snow and  
hail that falls continually upon the    
tops of these glacial mountains4 ,we    
have seen that ice possesses certain    
viscous or semi-fluidic properties and  
that it will yield to pressure1 but if  
we put it under sufficient tensional    
strain it snaps like glass or any other 
brittle substance4 ,as the snows upon   
these mountains pile up higher and      
higher the pressure becomes greater and 

greater until it reaches a point where  
the mass begins to move gradually down  
the mountain side1 following the gulches
 and defiles that furnish a path of     
least resistance to its flow4  ,at the  
sides and bottom1 where there is contact
 with the earth1 the movement is slower 
than it is at the surface and in the    
middle of the ice stream4 ,if there were
 no curves in the ravine or gulch       
through which it flows the point of     
greatest movement would be confined to  
the middle of its width4 ,but in flowing
 through a winding gulch the most rapid 
flow follow the lines of greatest       
pressure1 and this line is deflected    
from side to side1 so that the line of  
greatest flow is more winding than is   
the bottom of the valley through which  
it flows4 7,the movement is called a    
flow1 but it is very sluggish1 only a   
few inches in a day1 as will appear     
later47  ,if the bottom and sides of the
 valley were straight the surface of the
 ice would be comparatively even2 ,i say

 comparatively1 for as compared with a  
smooth surface it would be very rough2  
but there would be none of the great    
crevasses or openings now to be found in
 the ice1 which sometimes are very large
 and extend to a great depth4 ,if in its
 downward course the bottom of the      
ravine suddenly becomes steeper1 the top
 of the ice is put under a tensional    
strain which causes it to break1 thus   
forming the crevasses4  ,if at the      
bottom of the descent the valley curves 
upward or preserves the straight line   
for a considerable distance1 these      
crevasses will close at the top and     
perhaps open at the bottom1 and the     
blocks of ice will freeze together to   
such an extent that the water caused by 
the melting ice will flow on top until  
it comes to another crevasse1 where it  
runs through to the bottom or underflow1
 which is always an attendant of a      
glacier4  ,the glacier continues its    
flow down the mountain side till in some
 cases it reaches quite to the valley   

below1 and in others it stops short1 as 
the action of the sun is so great that  
it melts entirely away at this point as 
fast as it moves down4 ,in the winter   
time1 however1 the glacier may flow far 
down into the valley and will accumulate
 greatly in bulk1 owing to the fact that
 the ice forms from the precipitation of
 snow on top faster than it melts away  
underneath4 ,if it were not for the fact
 that in summer the glaciers melt faster
 than they form1 the whole valley would 
in time become a great river of ice4 ,it
 is the case in ,switzerland that some  
years the accumulation is greater from  
snowfall than diminution from melting4  
,if this condition should continue it   
would become a serious matter4  ,in the 
downward flow of a glacier--slow as it  
is--there is an exhibition of wonderful 
power2 great bowlders are torn from     
their beds and either ground to powder  
or carried down to the end of the       
glacier1 to be dropped with the other   
debris that has been carried there by   

the same force1 forming an accumulation 
that geologists call the moraine4 ,of   
these moraines we will speak more fully 
later on4  ,it was the privilege of the 
writer some years since to visit the    
great glaciers of ,switzerland and to   
some extent study their action4 ,some   
rivers have their origin chiefly in     
melting glaciers4 ,they start as ice    
rivers and end in rivers of water4 ,the 
effects during the great ice age of some
 of these glacial rivers1 which are now 
extinct1 are very remarkable2 we shall  
have occasion to refer to them when we  
come to treat of the glacial period4    
,there is a glacial river flowing which 
is fed largely by the great ,rhone      
glacier in ,switzerland4 ,the water from
 this river is almost as white as milk1 
which is occasioned by the grinding     
action of the great ice blocks on the   
rock as it flows down the sides of the  
mountain4 ,these glacial rivers are much
 higher in summer1 of course1 than in   
winter1 some of them having not only an 

annual fluctuation1 but a diurnal one4  
,the former is caused by the cold of    
winter1 and the latter because it       
freezes to some extent at night and     
checks the flow of water4 ,the          
difference between day and night in     
these high altitudes is very marked4    
,while it is extremely hot in the sun1  
it is cool the moment we step into the  
shade4  ,i remember walking across one  
of the glaciers in the ,alps1 called the
 ,mer de ,glace1 one clear day in       
summer1 when ,i suffered so much from   
the heat1 although standing upon a sea  
of ice1 that it was necessary to carry  
an umbrella4 ,in fact1 during my stay   
there was a case of sunstroke that      
occurred upon this same glacier4 ,this  
intense heat during the day melts the   
surface of the ice1 which forms streams 
that run along on the top of a glacier  
until they come to a crevasse or riffle 
in the ice river1 where they plunge down
 and become a part of the glacial stream
 that is flowing underneath the ice4    

,the speed at which these ice streams   
flow varies greatly with the size of the
 glacier as to width and depth and the  
steepness of the grade1 and many other  
conditions4 ,in its movement the glacier
 is constantly bending and freezing and 
being torn asunder by tensional strain1 
yielding and liquefying at other points 
by pressure1 only to freeze again when  
that pressure is removed4 ,this1 taken  
in connection with the friction of the  
great ice bowlders1 produces a movement 
that is exceedingly complicated in its  
actions and interactions4  ,according to
 ,professor ,tyndall's investigations1  
the most rapid movement observed in the 
glaciers of ,switzerland is thirty-seven
 inches per day at the point of greatest
 movement4 ,from this point each way the
 motion gradually diminishes until it   
reaches the sides of the glacier1 where 
the motion is not more than two or three
 inches4  ,the great ,north ,american   
glaciers move at a much higher rate of  
speed4 ,we are indebted to ,dr4 ,g4     

,frederick ,wright1 author of ,the ,ice 
,age in ,north ,america1 who spent a    
month studying the ,muir glacier in     
,alaska1 for many details concerning    
that great ice river4 ,this glacier     
empties into ,muir ,inlet1 which is an  
offshoot of ,glacier ,bay4 ,it is       
situated in latitude #eh degrees #ej    
minutes and longitude #acf degrees #dj  
minutes west of ,greenwich4 ,the bay    
into which this glacier empties is about
 thirty miles long and from eight to    
twelve miles wide4 ,this bay1 with its  
great glacier1 has a setting of grand   
mountain peaks4 ,i cannot do better than
 to quote the words of ,dr4 ,wright when
 he describes the location of this      
glacier4 ,dr4 ,wright lived for a month 
in a tent on the edge of this bay1 a    
short distance below the face of the    
great glacier1 where the icebergs fell  
off every few minutes into the deep     
water4  ,he says3 ,to the south the calm
 surface of the bay opened outward into 
,cross ,sound twenty-five miles away4   

,the islands dotting the smooth surface 
of the waters below us seemed but       
specks1 and the grand vista of snowclad 
mountains guarding either side of       
,chatham ,strait seemed gradually to    
come to a point on the southern horizon4
 ,westward toward the ,pacific was the  
marvelous outline of the southern       
portion of the ,st4 ,elias ,alps4 ,the  
lofty peaks of ,crillon1 #ae1ijj feet   
high1 and ,fair ,weather1 #ae1ejj feet  
high1 about twenty-five miles away and  
about the same distance apart1 stood as 
sentinels over the lesser peaks4  ,the  
,muir glacier might be likened to a     
great inland sea of ice fed by many     
tributaries or ice rivers4 ,it narrows  
up at the point where it empties into   
,muir ,inlet to #aj1ffd feet1 or a      
little over two miles4 ,an enormous     
pressure is exerted at this point1 which
 causes the ice to flow in the central  
portion at the rate of about seventy    
feet per day4 ,there is a continual     
booming1 like the firing of a cannon1   

going on1 caused by the bursting of some
 great iceberg either before it takes   
its final leap into the water or at the 
moment of its fall4 ,at the point where 
these great icebergs drop off into the  
water they stand like a solid wall #cjj 
feet above its surface4 ,dr4 ,wright    
says3 ,from this point there is a       
constant succession of falls of ice into
 the water1 accompanied by loud reports4
 ,scarcely ten minutes1 either night or 
day1 passed during the whole month      
without our being startled with such    
reports2 and frequently they were like  
thunder claps or the booming of cannon  
at the bombardment of a besieged city1  
and this though our camp was two and    
one-half miles below the ice front4444  
,repeatedly ,i have seen vast columns of
 ice extending up to the full height of 
the front topple over and fall into the 
water4 ,how far these columns extended  
below the water could not be told       
accurately1 but ,i have seen bergs      
floating away which were certainly #ejj 

feet in length4  ,it is estimated that  
the cubical contents of some of these   
icebergs are equal to #dj1jjj1jjj feet4 
,this great glacier is fed by the       
constant precipitation of snow upon the 
sides and peaks of the high mountains   
that surround its vast amphitheater1    
which is floored with icebergs4         
,wonderful as this seems to us to-day1  
it is scarcely a microscopic speck of   
what existed during the ice age all over
 the northern part of ,north ,america4  
,there are many other great glaciers in 
the mountains of the ,pacific coast4    
,some years ago ,i saw one of these     
immense glaciers in ,british ,columbia1 
from a point called ,glacier ,station1  
in the ,selkirk ,mountains1 on the      
,canadian ,pacific ,railroad4 ,it was   
during the month of ,august1 when all of
 the region was pervaded by a dense     
smoke occasioned by burning forests4    
,this glacier is a very showy one1 owing
 to the steepness of the side of the    
mountain and its great breadth4 ,all the

 glaciers that exist to-day are         
gradually receding1 and are destined    
eventually to entirely disappear1 unless
 there is a change in meteorological    
conditions1 which some scientists claim 
will be the case if we only wait long   
enough1 when again all this northern    
country will be covered with a great ice
 sheet4 ,there is no doubt in regard to 
the facts concerning a glacial period   
that must have existed in the ages past4
 ,to anyone who has made a study of the 
subject there is not wanting abundant   
evidence to prove that this northern    
country was at one time enveloped with a
 great ice sheet of enormous thickness4 
,the conditions that existed to bring   
about such a state of things have been  
the subject of much speculation by      
philosophers1 but no one1 as yet1 has   
arrived at any very satisfactory        
conclusion4 ,many theories have been    
advanced1 some of them not worth        
considering1 while others have many     
things that give them a show of         

plausibility4 ,but all of them have what
 is said of the ,darwinian theory1 a    
missing link4 ,it will be interesting1  
however1 and also instructive1 to know  
what can be said in favor of a set of   
conditions that would produce such      
momentous results4     ,,chapter ,,xxvi4
  ,,evidences ,,and ,,theories ,,of ,,an
 ,,ice ,,age4   ,there is abundant and  
unassailable evidence that at one time1 
ages ago1 a vast ice sheet covered the  
whole of the northern part of ,north    
,america1 extending south in ,illinois  
to a point between latitudes #cg and    
#ch4 ,this is the most southerly point  
to which the ice sheet reached4 ,from   
this point the line of extreme flow runs
 off in a northeasterly and             
northwesterly direction4 ,the           
northeasterly line is through           
southeastern ,ohio and ,pennsylvania1   
striking the ,atlantic ,ocean about at  
,new ,york1 thence through ,long ,island
 and up the coast of ,massachusetts4    
,northwesterly it follows the           

,mississippi ,river to its junction with
 the ,missouri1 which it crosses at a   
point some miles west of this junction1 
following the general course of this    
river a little south of it through the  
,states of ,missouri1 ,nebraska1        
,dakota1 and ,montana4 ,the lines1      
especially the northeasterly one1 are   
very irregular1 shooting out into curves
 and then receding4 ,this line of       
extreme ice flow is marked by glacial   
drift so prominently that no one who has
 studied glacial action can doubt for a 
moment what was the cause of these      
deposits4 ,the line is called the       
terminal moraine4 ,by examining a map of
 ,north ,america and tracing the line of
 the moraine as we have described it1 it
 will be seen that about two-thirds of  
,north ,america was at one time covered 
with ice to a greater or less depth4    
,how deep1 is simply a matter of        
conjecture1 but in the central portions 
of the great glacier1 where was the bulk
 of snowfall1 it must have reached a    

depth of several miles to account for   
the enormous pressure that would be     
required to carry the ice so far        
southward4  ,but let us go back and     
define what is meant by a moraine4 ,a   
moraine is a name given to the deposits 
that are of stone1 gravel1 and earth    
that have been carried along by the     
movement of the glaciers and deposited  
at their margins1 sometimes piled up to 
great depths4 ,the composition of these 
moraines is determined of course by the 
nature of the country over which the    
stream of ice is flowing4 ,bowlders of  
enormous size have been carried for     
hundreds of miles1 and the experienced  
geologist is able to examine any one of 
them and tell us where its home was     
before the glacial period4 ,moraines are
 divided into different classes         
according to their position and         
constitution4 ,the moraine found at the 
extreme limit of ice-flow is called the 
terminal moraine1 as before mentioned4  
,those that are found inside of this    

line and between two flows are called   
medial moraines4 ,there is a subdivision
 called kettle or gravel moraines1 which
 are very prominent in northern         
,illinois and southern ,wisconsin1 and  
may be said to culminate in the vicinity
 of ,madison4 ,this moraine is a great  
deposit of gravelly soil4 ,where this   
moraine exists the face of the country  
is covered with kettle holes of all     
sizes and shapes1 and in some of them   
there are small lakes1 while others are 
dry4 ,the great chain of inland lakes   
that are found in southern ,wisconsin   
and northern ,illinois were formed by   
deposits of ice that had been covered by
 glacial drift1 gravel and otherwise1   
brought down and deposited upon these   
masses of ice which gradually melted    
away1 leaving a depression at the points
 where they lay1 while the drift that   
was piled around them loomed up and     
became the shores of the lake4 ,this is 
substantially ,dr4 ,wright's theory1 who
 studied the formation of these kettle  

holes at the mouth of the ,muir glacier4
 ,this enthusiastic glacialist has spent
 many summers tracing the terminal      
moraine with its fringe along the lines 
heretofore indicated4 ,he is1 therefore1
 entitled to speak with authority on    
matters of glacial action4  ,the part of
 the country that has been plowed over  
by these glaciers is called the         
glaciated area and the rest the         
unglaciated4 ,the whole of ,north       
,america north of the line of the       
terminal moraine that we have traced is 
a glacial region1 with the exception of 
a few hundred square miles chiefly in   
,wisconsin1 where the ice seemed to have
 parted and passed around this area1    
coming together again on the south side 
of it4 ,the ice probably did not reach  
the extreme limit that shows glacial    
deposit1 but undoubtedly the effects of 
it are seen for some distance to the    
south1 owing to the fact that during the
 time it was melting great quantities of
 water flowed away from the extreme edge

 of the ice1 carrying with it more or   
less of the glacial drift1 which was    
deposited for some distance to the      
south4 ,when the ice receded it         
undoubtedly paused at different points1 
where it remained stationary for a long 
period of time4 ,i mean stationary at   
its edges1 for the flow of ice was      
continually moving1 but in its progress 
southward it came to a point where the  
heat was sufficient to melt the ice as  
fast as it arrived at that point4 ,the  
on-moving ice was continually bringing  
with it the debris that it had gathered 
up at different points on its journey1  
so that it is easy to see how these     
moraines could accumulate to a greater  
or less depth at the margin of the ice  
flow1 which would be determined by the  
duration of the period it remained      
stationary4 ,this1 however1 is only one 
factor1 as the surface of the earth in  
some parts of the country would be more 
easily picked up and carried than in    
others2 therefore1 the drift accumulated

 much more rapidly in some sections than
 in others4  ,another factor that was   
active in the more rapid accumulation at
 certain points was the speed at which  
the ice moved1 and this would be        
determined by the pressure that was     
behind it1 and there would always be    
lines of unequal pressure existing in   
such a great glacier as must have       
existed when these moraines were formed4
  ,as an instance of the difference in  
the glacial deposits that are made in   
different periods during the time of the
 melting of the great ice sheet we may  
compare the ,kettle ,moraines of        
,wisconsin with the clay deposit mixed  
with broken gravel that we find along   
the west coast of ,lake ,michigan4      
,those whose homes are situated between 
,winnetka and ,waukegan on the lake     
shore have the foundations of their     
houses set in glacial drift that was    
shoved into position by the ice during  
the glacial period4  ,anyone who makes  
an examination of the bluffs along the  

shore of this lake will notice that     
there is no stratification whatever to  
the deposit such as will always be found
 in an unglaciated region4 ,going west  
from the bluff a few miles we come down 
to the prairie level1 where we find the 
soil of an entirely different nature4   
,the soil of the prairies of ,illinois  
and ,iowa is probably to a great extent 
a water deposit4 ,it is the kind we find
 in the bottom of a pond that has stood 
for many years1 and it would seem that  
at some period all this prairie country 
with the black soil was the bottom of a 
great lake4  ,the facts of a glacial    
period are beyond question1 but when it 
occurred1 and how it occurred are       
questions that many have tried to       
answer4 ,so far1 all that we can say of 
them is that some of them are shrewd    
guesses4 ,the evidences adduced for     
determining the time1 are the erosion   
caused by rivers and streams since the  
ice subsided4 ,some of the rivers and   
outlets of lakes had their courses      

changed by the action of the ice1 so    
that when it subsided new water courses 
were formed1 and the erosion that they  
have produced from that time to the     
present furnishes the data for          
determining the time since the          
subsidence of the ice at any particular 
point4 ,for instance1 ,niagara ,falls   
was undoubtedly at one time situated at 
,queenstown1 a number of miles below its
 present position4 ,and the time that it
 has taken to grind out the great gorge 
that exists between that point and the  
present falls is approximately a measure
 of the time that has elapsed since the 
subsidence of the ice at that point4    
,various estimates have been made to    
determinate the rate of erosion4 ,the   
earlier ones put the time at about      
#ce1jjj years4 ,but there are later     
investigators who make the time much    
shorter1 not over #aj1jjj years4  ,so   
much for the time2 but you ask ,what    
about the occasion1 or cause8 ,this is a
 question that many have attempted to   

answer1 there having been eight or ten  
theories promulgated with regard to the 
cause of the glacial period1 but no one 
of them is entirely satisfactory1 and   
only two or three of them are deserving 
of much discussion4 ,it is always       
interesting to know what people think1  
however1 even if we do not agree with   
them4  ,the first theory named is that  
the glacial period is due to the        
decrease of the original heat in our    
climate4 ,this theory can be dismissed  
by saying that the planet was cooling at
 the time and has been cooling ever     
since1 and that the reasons for an ice  
age are greater now than then1 on that  
theory4 ,another theory assumes that at 
some former period there was a greater  
amount of moisture in the atmosphere2   
while this of course would be the       
occasion for greater precipitation of   
snow1 it does not account for the       
changing conditions that would produce  
the ice effect4 ,that there was a       
preglacial period there is abundant     

evidence1 in buried forests1 the filling
 up and changing of river beds1 and     
other evidences that will be referred to
 further on4 ,this theory1 unmodified   
and stated broadly1 is not satisfactory4
 ,another way of accounting for the     
glacial period is the change in the     
distribution of land and water1 which is
 supposed to affect the distribution of 
heat over the earth's surface4 ,there is
 much in this theory that commends      
itself as plausible4 ,another theory    
supposes that the land in northern      
,europe and ,america was elevated to a  
higher level at that time than it is    
now4 ,others attribute it to variation  
of temperature in space and of the      
amount of heat radiated by the sun4 ,the
 final theory for accounting for the ice
 age is attributed to what is termed the
 precession of the equinoxes4 ,in short1
 the precession of the equinoxes means  
that the division between summer and    
winter is changing gradually1 so that   
during a period of #aj1ejj years the    

summers are growing longer in the       
northern hemisphere and the winters     
shorter4 ,we are now in the period of   
long summers1 but in another #aj1jjj    
years we shall be in the period of short
 summers and long winters4 ,this        
difference of time between the winters  
and the summers is supposed to be       
sufficient to change the thermal        
conditions sufficiently to produce an   
ice age4  ,it is true that the          
conditions now are very evenly balanced1
 so much so that in ,switzerland the    
glaciers will increase for some years   
together1 when the conditions will      
change1 causing them to gradually       
recede4 ,several of the theories that   
have been advanced present evidences    
that are entitled to careful            
consideration1 but none of them can be  
said to be entirely satisfactory4 ,it is
 well known that the chief factors in   
the production of glaciers are moisture 
and cold4 ,cold alone is not sufficient2
 neither is moisture1 unless we can     

precipitate it in the form of snow4     
,cold is opposed to the production of   
moisture1 and this is a flaw in the     
argument presented by the last theory1  
unless we can couple with it another set
 of conditions which we will discuss    
later4  ,the solution1 if it is ever    
reached1 is perhaps more likely to be   
found in the realm of meteorology than  
geology4  ,it is unnecessary to change  
the conditions of temperature or the    
amount of moisture now existing in order
 to produce the great glacier again1    
provided this moisture could be         
precipitated1 enough of it1 in the right
 place as snow4 ,for instance1 if in    
,switzerland1 where the conditions are  
nearly balanced1 the annual             
precipitation could be slightly         
increased we should have a condition    
that would precipitate more snow in     
winter than would melt in summer4 ,and  
the glaciers would gradually accumulate 
in size until they would fill the       
valleys and gorges to the same extent as

 formerly prevailed4 ,there only needs  
to be such a change in the              
meteorological conditions as will cause 
a greater precipitation in that part of 
the globe favorable to glaciers1 as1 for
 instance1 in the northern part of      
,north ,america toward ,alaska4 ,this   
might be produced by a change in the    
conditions of the equatorial current1 so
 that evaporation would be more rapid in
 the northern ,pacific than it now is4  
,when we consider that evaporation      
increases in proportion as the heat     
increases1 we can see that heat is just 
as important a factor in the production 
of glaciers as cold4 ,if evaporation    
could be increased in the ,pacific      
,ocean west of ,alaska1 which would be  
carried by the wind over the mountains  
upon the land1 and precipitated as snow1
 the great glaciers in that region would
 begin to grow instead of gradually     
receding1 as is the case at present1 and
 this without any change in the         
temperature of the world as a whole or  

in the amount of heat received from the 
sun4 ,one can readily see how changes in
 the elevation of the bottom of the     
ocean would have such an effect upon the
 tropical stream as would either        
increase or decrease the temperature of 
the thermal river that flows up the     
western coast of ,alaska4  ,whatever may
 have been the cause that created the   
great ice age in ,north ,america1 so    
that a sheet of ice covered considerably
 more than half of the continent1 there 
is no doubt in regard to the fact of the
 existence of such an age1 and it will  
be interesting to study some of the     
physical changes that have been made by 
the ice at that period on the surface of
 the glaciated area4     ,,chapter      
,,xxvii4  ,,glacial ,,and ,,preglacial  
,,lakes ,,and ,,rivers4   ,since the    
recession of the ice1 preglacial lakes  
have been filled up and are now dry     
land1 and river beds have been changed  
so that new channels have been cut and  
new lakes have been formed4 ,even the   

imagination1 that wonderful architect1  
with all its tendencies to exaggeration1
 palls in its attempt to give expression
 in measured quantities to the mighty   
power exerted by the great glacier or   
combination of glaciers that existed in 
comparatively recent times4 ,i say      
recent times1 because even #aj1jjj years
 is only a mere point of time when      
compared with the actual age of our     
globe4  ,some years ago1 in company with
 ,dr4 ,wright1 author of the ,ice ,age  
in ,north ,america1 ,i visited ,devil's 
,lake near ,baraboo1 ,wis4 ,at this     
point are striking evidences of the work
 of the ice age4 ,before the glacial    
period the ,wisconsin ,river made a     
detour some miles west of its present   
channel through the high hills in the   
region of ,baraboo4 ,the hills on each  
side of ,devil's ,lake are very         
precipitous and are formed almost       
entirely of rocks4 ,the river at that   
point passed between two of these hills4
 ,when the ice flowed down it surrounded

 these hills1 yet did not sweep over    
their tops1 but left great piles of     
glacial drift1 both at the points where 
the river channel entered the hills and 
where it emerges from them4 ,the channel
 between the hills was protected and not
 filled with the debris4 ,therefore a   
deep basin was left1 which is kept      
filled by the watershed furnished by the
 surrounding hills4 ,this lake recedes  
many feet during the summer1 but it is  
again filled up by the rains and snows  
of winter4 ,there is no considerable    
stream either flowing into or out from  
it4 ,it is a lake formed by the         
glaciers1 but in a different way from   
those in the gravel deposits at other   
parts of southern ,wisconsin and        
northern ,illinois4  ,there are hundreds
 and perhaps thousands of lakes that    
have been formed in one way or another  
through the power of glacial action4    
,these smaller inland lakes1 so many of 
which are seen in northern ,illinois1   
southern ,wisconsin1 and ,minnesota1 are

 due almost entirely to the great       
deposits of glacial drift that have been
 transported with the ice4 ,wherever    
these kettle holes are found large      
bodies of ice have become anchored1     
while the ice behind it has carried the 
drift until it is covered over and piled
 up at the sides4 ,when these ice       
mountains melted away depressions were  
left which in some cases have resulted  
in lakes1 and in others simply dry      
kettle holes4 ,this process has been    
hinted at in a former chapter1 but we   
give it here as one of the kinds of     
lakes formed during the glacial period4 
,they are found everywhere that glacial 
action has prevailed4 ,they are found in
 great abundance in some parts of ,new  
,england on the margin of the terminal  
moraine4 ,these lakes1 however1 are     
comparatively insignificant as compared 
with the great inland seas like ,lake   
,superior and ,lake ,michigan1 that     
undoubtedly owe their origin largely to 
the ice age4  ,there are other factors1 

however1 that enter into the formation  
of the great chain of lakes on the      
northern boundary of the ,united ,states
 besides those mentioned1 that have     
brought into existence the smaller      
inland lakes4  ,glacial lakes may be    
divided into three classes4 ,those found
 in the kettle holes of the terminal or 
medial moraines1 and those that are     
formed by the deposition of the glacial 
drift1 as1 for instance1 ,devil's ,lake1
 and those that are caused by ice       
forming dams across the valley of a     
river that lasted only during the ice   
age4 ,in some lakes of the second class 
erosion undoubtedly entered into their  
formation as well as the piling up of   
glacial drift4  ,in order1 however1 that
 we may understand more fully the       
formation of these greater lakes it will
 be necessary for us to go back and     
examine the conditions that seem to have
 existed before the glacial period4  ,it
 is a fact well known that continents   
have periods of elevation and           

depression4 ,there is abundant evidence 
that the northern portion of the ,north 
,american continent was elevated to a   
much higher level in preglacial times   
than it occupies now4 ,this is evidenced
 in very many ways by sounding the      
depths of old river beds now filled with
 glacial debris4 ,the old beds show     
unmistakable evidences of having been   
worn down to their present level by the 
action of running water4 ,they also     
prove to be many feet below the present 
sea-level4 ,this fact seems to be       
sufficient to prove the theory of a     
higher elevation of the ,north ,american
 continent in preglacial times4 ,it     
should be said here that undoubtedly the
 constant filling up of the ocean with  
the drift carried down by the rivers has
 somewhat raised its level1 but hardly  
to the extent indicated by the old river
 beds4 ,the question naturally arises1  
,where did all the dirt come from to    
fill up these great river beds and      
change the whole topography of the      

northern half of the continent8 ,dr4    
,wright estimates that there is not less
 than #a1jjj1jjj square miles of        
territory in ,north ,america covered    
with glacial debris to an average depth 
of #ej feet4 ,of course1 the depth      
varies in different places from a few   
inches to several hundred feet4 ,of the 
carrying power of these great glaciers  
we will speak more fully in a future    
chapter4 ,in preglacial times the       
watershed of the ,mississippi and of the
 great rivers east of the ,alleghany    
,mountains1 the ,susquehanna and        
,hudson1 extended probably farther north
 than it does to-day4 ,the larger       
portion of the drainage area that now   
finds an outlet through the ,river ,st4 
,lawrence at one time undoubtedly       
drained off through the ,mississippi    
,valley into the ,gulf and the ,valley  
of the ,mohawk into that of the ,hudson4
  ,it is supposed by those who have made
 this branch of geology a study that    
prior to the glacial period a river     

flowed down through ,lake ,superior1    
which connected with ,lake ,michigan at 
a point near its present outlet at      
,sault ,ste4 ,marie1 the channel of the 
river passing down through what is now  
the bottom of ,lake ,michigan1 which had
 an outlet at the head of the lake near 
,chicago and flowed off into the        
,mississippi ,river4 ,all of the lake   
bottoms of this great chain1 with the   
exception of ,lake ,erie1 are now below 
sea-level4 ,the reason for this         
exception will appear further on4       
,before the ice age there was supposed  
to be no connection between ,lake       
,michigan and ,lake ,huron1 as there is 
now1 through the ,straits of ,mackinac4 
,another preglacial river had its rise  
in the region of ,lake ,huron and flowed
 through an old river bed extending from
 the ,georgian ,bay in a southeasterly  
direction through the province of       
,ontario1 and emptied into the present  
,lake ,ontario4 ,from ,lake ,ontario    
there is an old river bed running       

through the ,valley of the ,mohawk which
 empties into the ,hudson at ,troy4     
,neither of these two rivers1 having    
their sources in the north1 found an    
outlet through the present ,st4         
,lawrence ,river4 ,during the time of   
the glacial period there is evidence    
that there was more than one center of  
snow and ice accumulation and each of   
these great centers probably had several
 subcenters4 ,this theory has color     
given to it by the directions of        
movement shown by the glacial drift4    
,the rounded appearance of bowlders was 
caused by the grinding action of the    
ice4 ,these bowlders1 when they were    
first torn from their rocky beds by the 
irresistible power of ice pressure1 were
 rough and jagged in shape1 the same as 
any rock would be1 torn from a quarry by
 a blast4 ,they have been smoothed and  
rounded by rubbing against the moving   
ice and against each other in the       
progress of their long journey from     
their original homes4 ,where their home 

was the geologist can immediately tell  
upon examination4 ,it is only necessary 
then to examine the bowlders of any     
particular locality to determine the    
direction of the ice flow at that point4
  ,there seem to have existed centers of
 ice accumulation to the north of all of
 the great lakes4 ,and when they had    
grown to a sufficient height they joined
 at their edges1 making one grand       
glacier1 the movements of which were the
 resultant of the combined pressure     
exerted by these great centers of power1
 so that all of ,north ,america north of
 the line of the terminal moraine1 with 
the exception of a small area           
7heretofore noted7 chiefly in           
,wisconsin1 became covered with one vast
 sheet of ice4  ,the glacier north of   
,lake ,superior widened out the old     
river bed by a process of erosion to its
 present width4  ,there may have existed
 something of a lake in preglacial      
times1 through which the river ran1 but 
it undoubtedly owes its present width to

 the grinding action of the irresistible
 icebergs and the piling up of debris on
 the shores4 ,the river bed was filled  
up by a glacial drift at the point of   
its present outlet until the lake was   
raised in its level much higher than    
that of ,lake ,michigan4 ,another       
glacier plowed down through ,lake       
,michigan1 widening it out to its       
present dimensions1 while the glacial   
drift was deposited at what is now the  
head of the lake1 filling up the old    
outlet and thus making a great dam4 ,the
 damming up of these great water courses
 was another cause for increasing the   
width of these lakes4 ,in a similar way 
,lake ,erie was formed4 ,it is supposed1
 however1 that this lake is entirely the
 product of glacial action1 as there is 
no evidence of an old river bed in its  
bottom2 besides1 it is much shallower   
than the other lakes4 ,the same action  
that formed ,lake ,erie filled up the   
old river bed running through the       
province of ,ontario1 so that when the  

ice receded ,lake ,erie became the new  
channel for the old river4 ,the same    
process filled up the ,valley of the    
,mohawk to more than #ajj feet in depth 
and also raised the ,valley of the      
,hudson4 ,this caused the new channel to
 be made through the ,niagara ,river and
 a new route to the ocean for the       
drainage of all the chain of lakes      
through the ,st4 ,lawrence4 ,it will be 
seen that the bottoms of all of these   
great lakes to a certain extent were    
worn out by the action of running water1
 except ,erie4 ,the great glaciers      
widened them out1 and in the case of    
,lake ,erie scooped it out4 ,at the same
 time it built great dams across the    
outlets which raised the surface of the 
water to a much higher level and caused 
them to form new outlets1 thus changing 
the whole face of the country over which
 the ice drifted4  ,the glaciated region
 of ,north ,america is among the most   
productive in the world1 and in many    
respects presents a most pleasing       

landscape4  ,other lakes besides these  
mentioned have been formed during the   
ice period through blocking the course  
of a river by the ice itself4 ,dr4      
,wright1 during the time he traced out  
the line of the terminal moraine1       
discovered that the ice sheet crossed   
the ,ohio ,river at a point near        
,cincinnati1 where there is a great bend
 to the northward in the river4 ,with   
the exception of this point and perhaps 
another point below1 the edge of the    
great ice sheet kept a little north of  
the ,ohio ,river4 ,at this point1       
however1 the ice seems to have filled   
the valley from hill to hill1 which very
 naturally would form a great dam or    
lake in the ,ohio ,valley4 ,of course   
such a lake could not be permanent1     
because1 when the ice melted away1 it   
again opened the channel and allowed the
 water to flow off4  ,some years before 
this discovery was made there were      
terraces found along the banks of the   
,ohio ,river and its tributaries that   

had been the subject of much            
speculation4 ,it is well known that by  
the action of water from rainfall1      
earth1 gravel1 and other debris will    
wash down the side of a hill or mountain
 until it strikes a water level1 and    
there it will build out a terrace near  
the level of the water surface4 ,the    
width of these terraces will be         
determined by the time the water has    
stood at that level and the extent and  
nature of the soil from which the debris
 comes4 ,the evidences that are cited1  
pro and con1 would fill a small volume1 
but it is sufficient to say here that   
the sum of the evidence goes to show    
that there was an ice dam formed at a   
point near ,cincinnati and that it was  
maintained for a considerable period of 
time4 ,terraces were formed running up  
the ,ohio and its tributaries           
corresponding to the level that the     
water must have risen to if the valley  
were filled up with ice4 ,these facts1  
taken with the greater fact that the ice

 sheet actually did cross the ,ohio     
,valley into ,kentucky1 as is shown by  
the terminal moraine1 seems to prove    
conclusively the existence of such a    
lake during the period that the ice     
rested at its extreme limit4 ,the fact  
that in some places successive terraces 
are found does not disprove the theory1 
because it is more than likely that when
 the ice receded it did so in successive
 stages1 remaining at different         
positions for a considerable length of  
time4 ,there is abundant proof of this  
in the successive moraines and also in  
the formation of successive terraces4   
,some of these terraces could have been 
formed from other causes4  ,it does not 
require any great stretch of the        
imagination to understand how numerous  
lakes1 much larger than any at the      
present day1 may have extended over     
large portions of the ,west and         
,northwest during the period that the   
ice was receding4 ,the ice did not stand
 with an even thickness over the surface

 of the glaciated area1 but at some     
points it moved down in great lobes1    
which marked the lines of greatest      
pressure as well as the greatest        
accumulation4 ,as the ice melted away1  
the thick bodies of ice might be many1  
many years in melting1 and they might   
block the outlet to a very extensive    
drainage area and thus form a great     
inland sea from the vast amounts of     
water that would come from the melting  
ice4  ,all of the region about          
,winnipeg1 in the ,red ,river country1  
covering great areas of hundreds of     
miles in extent1 is a level plain only  
lacking the coloring to give to one     
passing through it the effect of a great
 unruffled sea4 ,there is no doubt but  
that all of this region was the bottom  
of a great lake at some period when the 
ice was receding4 ,and this accounts for
 the great depth of black soil that we  
find in this and other regions4 ,the    
soil was a water deposit1 such as may be
 found in the bottom of any shallow lake

 or pond to-day1 and thus many thousand 
years ago provision was made for the    
fertile areas which to-day are feeding  
the world with wheat4  ,we can imagine  
that during this period the water that  
flowed off through the great            
,mississippi must have been of enormous 
volume as compared to the present time4 
,a large portion of the delta of the    
,mississippi which now is a part of the 
,states of ,louisiana and ,mississippi  
was carried down during the ice-melting 
period4 ,dr4 ,wright--as we have before 
stated--has estimated that there are a  
million square miles of country that has
 been covered to an average depth of    
fifty feet with glacial drift4 ,a very  
large amount of the earth that was      
spread over the northern portion of the 
,united ,states by leveling down hills  
and mountains in the northern country   
and scooping out the great lakes has    
been carried much farther than to the   
margin of the ice sheet4 ,and ,i have no
 doubt but that a great portion of      

,louisiana and western ,mississippi is  
made of earth carried down largely      
during the period of melting ice and    
deposited in this great delta4  ,imagine
 the effect that would be produced by   
the giving way of an ice dam or a great 
number of them at different periods1    
that would allow a body of water as     
large or larger than ,lake ,michigan to 
be drained off in a comparatively short 
time4 ,when we think of it in this light
 the great delta of the ,mississippi is 
easily accounted for4  ,there are       
evidences of a great lake in the ,red   
,river country of the ,northwest that is
 much larger than any of our greatest   
lakes4 ,the shores of this lake--the bed
 of which is now dry land and the heart 
of a great agricultural region--are well
 defined and have been surveyed and     
mapped out4 ,when this great body of    
water was released it was to the        
northward4 ,for this reason it was      
undoubtedly held for a much longer time 
than some of the lakes to the southward 

where the ice melted sooner4            
,,chapter ,,xxviii4  ,,some ,,effects   
,,of ,,the ,,glacial ,,period4   ,there 
is a wonderfully interesting effect     
produced by the action of water during  
the subsidence of a glacier at ,lucerne1
 ,switzerland4 ,some years ago there was
 discovered under a pile of glacial     
drift at the edge of the town of        
,lucerne a number of deep holes worn in 
a great ledge of rocks that crop out at 
that point4 ,one of these pot-holes     
having been discovered1 excavations were
 continued until a large number of them 
were unearthed of various shapes and    
sizes4 ,i had the pleasure of inspecting
 some of them in the year #ahha4 ,they  
are situated within an inclosure called 
the ,garden of the ,glaciers4 ,some of  
these holes are twenty to thirty feet in
 diameter1 and the same depth4 ,there   
are others that are smaller in size1 but
 all of them possess the same general   
characteristics4  ,in the bottom of each
 one was found a bowlder1 and in one or 

two cases two of them4 ,the action of   
the water had given these bowlders a    
gyratory motion1 which gradually wore   
away the rock underneath until round    
holes were formed to the size and depth 
heretofore mentioned4 ,where there was  
only a single bowlder the holes were    
almost perfectly round1 but where there 
was more than one bowlder the holes were
 sometimes in an oblong shape4 ,the     
bowlders were worn down to a very small 
size in most cases1 and were round and  
smooth4 ,the probabilities are that when
 the action first began these bowlders  
were large and of irregular shape4 ,they
 must have been1 in order to do the     
enormous amount of grinding that some of
 them did to produce excavations in the 
solid rock with a diameter of thirty    
feet and a depth about the same4 ,the   
bottoms were round like an old-fashioned
 pot1 and the insides polished perfectly
 smooth4 ,this was purely an effect of  
the tumbling about of the bowlders by   
the running water from the melting ice  

of the great glacier that covered that  
region some time in the long ago4       
,there are other effects produced in    
rocks during the ice flow in ,north     
,america that are very interesting4     
,great grooves are formed in the rocks1 
in many cases running for long          
distances1 that have been worn in by the
 cutting power of the great ice sheet   
during the progress of its movement4    
,there is a great groove to be seen at  
,kelly's ,island in ,lake ,erie4 ,it    
will be remembered that this lake is    
supposed to have been formed entirely by
 the ice of the glacial period4 ,in its 
movement across the country which is now
 covered by the lake the ice encountered
 a huge rock formation at ,kelly's      
,island4 ,great ,v-shaped grooves were  
cut through this rock by the action of  
the ice1 deep enough for a man to stand 
in4 ,in other places the rock was planed
 off in the form of a great molding1 a  
number of feet wide1 with the same      
smoothness and accuracy as though done  

by a machine4  ,another effect of the   
glacial period has been the creation of 
numerous waterfalls throughout the      
glaciated area4 ,the most notable       
instance is that of the ,falls of       
,niagara4  ,in preglacial times the beds
 of all rivers and water courses had    
worn down to an even slope1 so that     
there were very few1 if any1 waterfalls 
such as we have to-day4 ,as we have     
before stated1 ,niagara ,river as well  
as the ,st4 ,lawrence ,river is a new   
outlet for the drainage of the great    
lakes4 ,a part of this drainage formerly
 had its outlet through the ,mohawk     
,valley into the ,hudson1 which is now  
filled up with glacial drift4 ,the      
evidence is so conclusive that it is no 
longer doubted that the ,niagara ,river 
dates from the time that the ice receded
 from that point4 ,when the water first 
began to flow through this new channel  
it plunged over the high rocky cliff at 
,queenstown1 and from that time to this 
it has been wearing its way back to the 

present position of ,niagara ,falls1 a  
distance of about seven miles4 ,a vast  
amount of interest centers about this   
river because it is the best evidence we
 have of the time that has expired since
 the glacial period4 ,a great deal of   
study has been given to determine the   
amount of erosion at the ,falls during a
 year's time4 ,if this could be         
accurately determined1 then by measuring
 the distance from the present falls to 
,queenstown1 we could easily determine  
the number of years since the ice       
period4 ,it is difficult to determine1  
for the conditions may have changed2 for
 instance1 the rock at the ,falls to-day
 is said to be harder than it is further
 down toward ,queenstown4 ,the estimates
 vary from #ce1jjj years to #aj1jjj     
years--that is1 from a rate of erosion  
of five feet to one foot1 per year4     
,every science is1 nearly or remotely1  
related to every other science4 ,if we  
could determine accurately the date of  
the ice period it would settle a whole  

lot of other questions that are related 
to it1 and one of them is the antiquity 
of man4 ,many stone implements such as  
were made and used by the aborigines    
have been found at various times buried 
deeply under the glacial drift4 ,these  
finds have occurred so often that there 
no longer remains a doubt but that a    
race of men existed on this continent in
 preglacial times4 ,there are evidences 
that at a time long ago the temperate   
zone extended far north of this1 and it 
is not impossible that what is now the  
continent of ,asia and that of ,north   
,america were joined4 ,in fact1 they    
come very close together to-day at      
,bering ,strait4 ,if such were the case 
this continent could have been inhabited
 from the old world by an overland      
route4 ,this1 however1 is mere          
speculation4 ,there are a number of     
factors that are taken into account in  
determining the period of the ice age   
besides the ,niagara ,river and the     
,falls4 ,the ,falls of ,st4 ,anthony at 

,minneapolis 7which like the ,niagara is
 a creature of the ice age71 the wear of
 water on the shores of the great lakes1
 the newness of the rocks that are piled
 up on the terminal moraines1 all point 
to a much shorter period since the ice  
age than it used to be supposed1 and    
indicate that the time does not exceed  
#aj1jjj years4  ,to the ordinary mind   
the ice age no doubt seems like a myth1 
but to the man of science who has made a
 study of all of these evidences it is  
as real as any fact in history1 and much
 more real than some of the history we  
read4 ,in the former case we are dealing
 with evidences that appeal to our      
senses1 while in the latter we are      
dealing with the recollections of men   
concerning what purport to have been    
actual transactions1 and we know enough 
about the human mind to make it         
difficult sometimes to draw the line    
between the actual and the imaginary4   
,the glacial period is not only closely 
related to the topography of ,north     

,america and parts of ,europe in the    
changing of river beds1 the formation of
 lakes1 the transportation of rock1 the 
grinding down of mountains and spreading
 the debris over thousands of miles in  
extent1 but it is related in an intimate
 way to many of the sciences1 such as   
botany and zooelogy4 ,a study of the    
flight of animals and plants in front of
 the great advancing ice sheet is a     
subject of intense interest4 ,the       
migration of great forests would seem to
 be an impossible thing when viewed from
 the standpoint of a casual observer4   
,it is true that individual trees could 
not take themselves up and move forward 
in advance of the oncoming ice1 but they
 could and did send their children on   
ahead1 and when the ice had overtaken   
the children there were still the       
children's children ad infinitum4  ,by  
an examination of the map it will be    
seen that the land gathers about the    
north pole1 while the south pole is     
surrounded chiefly by great oceans4 ,as 

we have hinted before1 in preglacial    
times the temperate zone extended much  
farther north than it does to-day1 and  
north of that there was an arctic zone  
7which to-day is largely covered with   
ice sheets71 where forests1 plants1 and 
animals flourished that were fitted for 
an arctic climate4 ,when the glacial    
period set in and the ice sheet began   
its southern journey this zone or       
climate was moved southward in front of 
the ice1 thus forming1 as it were1 a    
moving zone whose climatic conditions   
were similar to those of the arctic     
regions 7at least so far as temperature 
was concerned7 in preglacial times4 ,the
 ice movement was so gradual that time  
was given for forests to spring up in   
advance of it that moved southward at   
about the same rate as that of the      
moving ice4 ,undoubtedly the average    
movement was very slow and was probably 
thousands of years reaching its         
southernmost limit1 which is now marked 
by the terminal moraine4 ,thus it will  

be seen that while the individual trees 
and plants could not move1 the forest as
 a whole could4 ,it was gradually being 
cut down on its northern limit and as   
gradually it grew up on the southern    
limit of the zone2 the ice movement     
being so slow that the young tree of    
to-day on the southern limit becomes a  
full-grown king of the forest by the    
time the relentless icebergs reach it   
and cut it down and thus the process    
went on until the plants1 trees1 and    
animals of the arctic region were driven
 hundreds of miles south of the great   
chain of lakes on the northern boundary 
of the ,united ,states4  ,many of the   
animals of preglacial times were unable 
to stand the strain of the ever-changing
 climatic conditions and have become    
extinct1 but their fossil remains are   
left to tell the story to the present   
and future ages4 ,much of the history of
 those times is a sealed book1 but the  
persevering energy of the glacialist and
 archaeologist is gradually turning the 

leaves of this old book and revealing   
new chapters of the wonderful story of  
the ice4  ,as the ice receded the arctic
 zone again traveled northward1 and many
 animals1 plants1 and trees that had    
survived the vicissitudes of the ice    
age1 traveled back with it4 ,some of    
them1 however1 became acclimated and by 
adapting themselves to the new          
conditions remained behind to live and  
grow with the aborigines of preglacial  
times4 ,some of the plants and flowers  
that grew in profusion immediately under
 the edge of the great ice sheet were   
unable to live under the new conditions 
of increased warmth--that came with the 
retrograde movement of the ice--and     
either had to follow closely the        
receding ice or escape to higher        
altitudes1 where they found a congenial 
clime4 ,thus it is that we have arctic  
plants and flowers above the timber line
 and near the snow line of our high     
mountains4 ,in proof of this theory it  
has been found that these arctic plants 

do not exist upon high mountains1 such  
as the ,peak of ,teneriffe1 where they  
have been isolated from the glaciated   
region4 ,the ,peak of ,teneriffe is     
situated on one of the ,canary ,islands1
 surrounded by water1 so that there was 
no possible chance for the arctic plants
 to seek refuge on these isolated       
elevations1 such as the continental     
mountains furnish4  ,thus it will be    
seen that the progression and recession 
of the ice have not only formed great   
lakes1 changed river beds1 and covered a
 million square miles of area with      
glacial drift averaging fifty feet in   
depth1 making many waterfalls and giving
 variety to the surface of the earth1   
besides producing the finest            
agricultural region in the world1 but   
have also given variety to our forests  
and plants wherever this ice sheet has  
extended4     ,,chapter ,,xxix4         
,,drainage ,,before ,,the ,,ice ,,age4  
,we have already said that during the   
ice age river-beds were changed1 valleys

 were filled up1 new lakes were made1   
and waterfalls created4 ,great as were  
the changes made by the carrying power  
of moving ice1 still greater were those 
made in preglacial times2 not1 however1 
from the action of moving ice1 but from 
running water4 ,erosion caused by       
running water has1 probably1 during the 
life of the world1 transported more     
material from place to place1 from      
mountain to valley1 and from valley to  
ocean1 than any other agency2 chiefly   
for the reason that it has been so much 
longer doing its work4  ,the valley of  
the ,ohio ,river1 a thousand miles or   
more in length1 together with the great 
number of feeders that empty into it1 is
 an instance of the wonderful erosive   
power of running water4 ,the valley of  
the ,ohio ,river will probably average a
 mile in width at its upper level and1  
deep as it is to-day1 it was much deeper
 in preglacial times4 ,there is evidence
 that the whole bed of the river was    
from #ajj to #aej feet deeper than it is

 at present4 ,this has been determined  
by borings at different points to       
ascertain the depth of the drift that   
was lodged during the glacial period in 
the trough of the ,ohio ,river4 ,anyone 
traveling up or down the river to-day   
can readily see that it is a great      
sinuous groove cut down through the     
earth by millions of years of water     
erosion1 and not only this1 but that at 
some time in its history this great     
valley has been partly filled1 forming  
on one or both sides of the river level 
areas--called bottom land4 ,these lands 
are exceedingly productive1 owing to the
 great depth and richness of the soil4  
,for many years the writer lived upon   
one of the rivers tributary to the ,ohio
 and often made trips by steamboat up   
and down the ,ohio ,river4 ,traveling   
along this river a close observer will  
be struck by the exactness of the       
stratifications in the rock and in the  
coal beds to be seen on each side of the
 river4 ,they match as perfectly as the 

grain of a block of wood when sawn      
asunder--showing that these coal beds   
were formed at an age long before the   
water cut this sinuous groove4 ,what the
 water was doing while these coal beds  
were forming will be brought out in some
 future chapter4 ,all the rivers that   
are tributary to the ,ohio1 such as the 
,monongahela1 the ,alleghany1 the       
,muskingum1 the ,tennessee1 the         
,cumberland1 the ,kentucky1 the ,wabash1
 the ,miami1 the ,licking1 the ,scioto1 
the ,big ,sandy1 the ,kanawha1 the      
,hocking1 and the ,great ,beaver1       
besides numerous smaller streams1 have  
their own valleys that have been worn   
away by the same process1 and to a      
greater depth than they now appear to   
be4 ,all of the material that once      
filled these valleys has been carried   
down by the water filling up the bottom 
of the ocean and building out the great 
delta of the lower ,mississippi4        
,mountains have been worn down and      
carried away by the action of the       

running water until their height is much
 lower than in former times4 ,the great 
lakes1 that were enlarged during the    
glacial period and in some cases wholly 
created--by the scooping out and damming
 up of the waterways and by piling      
glacial drift around their shores--have 
had some of their outlets raised to a   
higher level1 and others have been      
created anew4  ,the old river beds that 
formerly carried the water that is now  
drained through the ,st4 ,lawrence were 
eroded by the action of running water to
 a great depth1 as is shown by numerous 
borings along the valley of the ,mohawk 
and down the ,hudson4 ,the salt wells at
 ,syracuse1 ,n4 ,y41 have been put down 
through glacial drifts and the salt     
water is found in the bed of the old    
river4 ,great bodies of salt are found  
at that low level1 constantly dissolved 
by the water percolating through the    
sand and gravel of the glacial drift4   
,this salt water is pumped up and       
evaporated1 leaving the salt--forming   

one of the important industries of that 
region4 ,all of the rivers from the     
,ohio eastward tell the same story1     
which is that at some remote period the 
land was much higher above the level of 
the sea than it is to-day4 ,the bottoms 
of many of these old river beds are     
lower than sea-level1 but as they were  
made by running water they must have    
been at one time above that point4      
,there is abundant evidence that the    
earth sinks in some places and rises in 
others4 ,along the ridges of some of the
 eastern mountains are found in great   
abundance the products of the bottom of 
the ocean4 ,these evidences show that at
 some period1 when the mountains were   
formed1 a great convulsion of nature    
raised the bottom of the ocean to       
thousands of feet above its level4      
,evidences of this exist in various     
parts not only of the ,united ,states1  
but of the world4  ,you ask1 ,if this   
erosion goes on and the mountains and   
hills are carried down and filled in to 

the low places of the ocean1 what is the
 final destiny of the earth that now    
appears above the surface of the ocean8 
,evidently if the earth should remain   
without further upheaval1 at some time  
in the far1 far future the land would   
gradually wear down and be carried off  
into the ocean and the ocean would      
gradually rise1 owing to its restricted 
area1 until it would again cover the    
whole earth as it undoubtedly did at one
 time in the earth's history4 ,this fact
 need not occasion any uneasiness on the
 part of those who are living to-day or 
for millions of years to come4  ,the    
problem of building a world and then    
tearing it to pieces is a very          
complicated one4 ,there is a constant   
battle going on between the powers that 
build up and those that tear down2 and  
this is as true of character-building as
 it is of world-building4 ,the world has
 never been exactly alike any two       
successive days from the time its       
foundations were laid to the present    

moment4 ,it seems to be a fundamental   
law of all life and growth1 as well as  
of all decay1 that there shall be a     
constant change4 ,there is no such thing
 as rest in nature4 ,the smallest       
molecules and atoms of matter are in    
constant agitation4 ,in the animal and  
vegetable world there is a period of    
life and growth1 and a period of decay  
and death2 and this seems to be the     
destiny of planets themselves as well as
 the things that live and grow upon     
them4 ,still1 science teaches us that   
with all this turmoil and change nothing
 either of matter or energy is lost1 but
 that it is simply undergoing one       
eternal round of change4 ,does this law 
apply to mind and soul8 ,do we die8 ,or 
do we simply change8         99       99
       99       99       99  ,nature's  
,miracles3  ,,familiar ,,talks ,,on     
,,science4  ,by ,,prof4 ,,elisha ,,gray4
  ,,vol4 ,i4--,world ,building and      
,life3 ,earth1 ,air and ,water4  ,,vol4 
,,ii4--,energy and ,vibration3 ,force1  

,heat1 ,light1 ,sound1 ,explosives4     
,,vol4 ,,iii4--,electricity and         
,magnetism4   ,elisha ,gray is a name   
known and honored by scientific men the 
world over4 ,farmer's boy1 blacksmith   
apprentice1 ship-joiner1 carpenter1     
self-supporting through a college       
course2 his genius interested him in    
electricity1 and in that realm his      
,inventions have made him famous4       
,these1 with his organization and       
presidency of the ,congress of          
,electricians at the ,columbian ,fair of
 #ahic1 and his many decorations and    
degrees1 conferred at home and abroad1  
all stand sponsors for his fame4  ,these
 little volumes convey scientific truth 
without technical terms1 and are        
enriched with reminiscence1 anecdote1   
and reflections that allure and hold the
 interest4       ,the place held by     
,elisha ,gray in the scientific world   
has      been won not by catering to the
 applause of the public1 but      by a  
life devoted to original investigation  

in untrodden      fields4--,chicago     
,times-,herald4   ,handy ,volumes1      
#d-a_/b x #f-a_/d2 ,cloth2 #fj cents per
 ,volume4   ,,fords1 ,,howard1          
,,hulbert1 #dg ,east #ajth ,st41 ,new   
,york4         99       99       99     
99       99  ,,bits ,,of ,,ore ,,from   
,,rich ,,mines4  ,,the ,,nuggets        
,,series4        ,don't ,worry ,nuggets3
 ,from ,epictetus1 ,emerson1 ,george    
,eliot1 ,robert ,browning4 ,gathered by 
,jeanne ,g4 ,pennington4      ,portrait 
of ,emerson4  ,might be marked ,multum  
in ,parvo4444 ,hardly a paragraph that  
does not bring a new sense of strength  
and comfort4--,chicago ,inter-,ocean4   
,patriotic ,nuggets3 ,from ,franklin1   
,washington1 ,jefferson1      ,webster1 
,lincoln1 ,beecher4 ,gathered by ,john  
,r4 ,howard4      ,portrait of          
,washington4  ,a peculiarly suggestive1 
readable1 useful compound of great      
historic thoughts from the greatest     
,americans4--,denver 7,col47            
,republican4       ,educational         

,nuggets3 ,from ,plato1 ,aristotle1     
,rousseau1      ,herbart1 ,spencer1     
,harris1 ,butler1 ,eliot4 ,gathered by  
,john ,r4      ,howard4 ,portrait of    
,plato4  ,no teacher1 no parent1 and no 
thoughtful person likely to become      
either one or the other1 but would      
benefit deeply by scanning and heeding  
these admirable selections4--,the       
,examiner1 ,new ,york4                  
,philosophic ,nuggets3 ,from ,carlyle1  
,ruskin1 ,charles ,kingsley1            
,amiel1 ,gathered by ,jeanne ,g4        
,pennington4--,portrait of              
,carlyle4  ,a handy book1 containing    
master thoughts from master minds1 is a 
desirable companion1 stimulating in     
thought and action4--,sunday-,school    
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,,howard1  ,,hulbert1 #dg ,east #ajth   
,st41 ,new ,york4         99       99   
99       99       99  ,by ,,henry ,,ward
 ,,beecher4        ,bible ,studies3     

,readings 7,genesis to ,ruth71 with     
familiar      ,comment4 ,edited by ,j4  
,r4 ,howard4 ,cloth1 #a4ej4       ,a    
,book of ,prayer3 ,invocations1 ,prayers
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,prayers from unpublished notes of ,t4  
,j4 ,ellinwood4      ,cloth1 #ge cts42  
cloth1 gilt1 #a4jj4       ,comforting   
,thoughts3 ,for ,bereavement1 ,illness1 
and      ,adversity4 ,compiled by ,irene
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limp1 #ge cts42 cloth1 gilt1 #a4jj4     
,beecher as a ,humorist4 ,wit and ,humor
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gilt1 #a4jj4       ,a ,book of ,prayer1 
,comforting ,thoughts1 ,beecher as a    
,humorist4 ,uniformly bound1 in a box1  
#b4be4       ,original ,plymouth        
,pulpit1 #ahfh to #ahgc4 ,ten vols4     
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,evolution and ,religion4 ,part         

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paper1 #a4jj4 ,bound in one      vol4   
,cloth1 #a4ej4       ,patriotic         
,addresses3 ,slavery1 ,civil ,war 7with 
the ,speeches      in ,england1 #ahfc71 
and ,civil ,liberty in the ,united      
,states1      #ahej-he4 ,with a ,review 
of his ,life1 ,personality1 and ,public 
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,portraits4 ,cloth1 #b4jj4       ,yale  
,lectures on ,preaching4 ,i4--,personal 
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,,iii4--,christian      ,doctrines4     
,thirty-three ,lectures4 #ifj pages4    
,three vols4 in      ,one4 ,vellum      
cloth1 #b4jj4       ,life ,of ,jesus the
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,cloth1      #a4ej4       ,royal        

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,words4 ,fourth      ,american from     
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,cloth1      #a4jj4                     
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,york4         99       99       99     
99       99  ,books by ,albion ,w4      
,tourgee4  ,,novels of the ,,south4     
,hot ,plowshares 7,rise of              
,anti-,slavery ,sentiment74 #a4ej4      
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novels 444 which have illustrated so    
forcibly and graphically the era of our 
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characters 444 humor 444 absorbing      
interest4--,boston ,commonwealth4  ,a   
,royal ,gentleman 7,master and ,slave74 
#a4ej4  ,grasps historic lines and      
mingles with them threads of love1      
mystery1 adventure1 crime1 battlefield1 
and hospital4--,albany ,evening         
,journal4  ,a ,fool's ,errand and ,the  
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#a4ej4  ,the book will rank among the   
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  ,scarcely anything in fiction so      
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books4 ,a ,fool's ,errand3 ,bricks      
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,republican4  ,john ,eax 7,the ,south   
,without the ,shadow74 #a4be4  ,rare    

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,murvale ,eastman3 ,christian           
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,uniform ,edition47  ,a thrilling story 
of everyday life 444 vividly            
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with a broad basis of the soundest      
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,black ,ice4 ,a ,story of the ,north4 ,a
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thoroughbred horses2 curious and        
interesting rural      characters4      
,cloth1 #a4ej4 ,uniform ,edition4       
,really original4--,boston ,gazette4    
,thoroughly interesting4--,chicago      
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7except ,john      ,eax1 #a4be74 ,set1  
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