The daily Alaskan., 1913-12-12
WATER PRESSURE
Tremendous Force EXerted at
 the Bottom of the Sea.
AIR THERE COULD NOT RISE.

It Would Be Compressed to Such a
 Degree of Density by the Enormous i Weight That the Water Would Float
 Upon It-Limits of Diving Depths.
 From ordinary considerations it
 would seem that there is no limit to
 the depths to which a diver or a sub
 marine boat might go. Such, how ever. is not the case. What prevents
 diving to great depths is the enormous
 ly increasing pressure of water. No | diver without a suit can go over l5O ! feet. because the pressure on the body | Is then about five tons to the square foot on his body. Eardrums would be staved in. and other fearful difficulties
 would result
 To remedy this the diving suit was invented. but there is a limit also to
 its depth At a depth of one mile the i pressure due to the water alone is l65 | tons to the square foot. Even if div
 ing suit was devised to withstand this
 enormous pressure trouble would be
 found in getting a pipe line that long and wirhstauding the pressure that would not break of its own weight In the case Of submarine hont it l Is slightly different. Here only the
 strength of the boat is the necessary
 thing. Rut to be strong the walls have to he thickencd. and this adds to the
 weight. consequently adding to the ! load to be nH1cl through the water, and SO at Iast the limit of the engine propcIing thp roat iS reached. If a larger engine is procured it itself
 weighs more. larger quarters are need. 1 ed for it. ctr Sn there is well de- ! fined limit tn marine boats diving
 Let Us take the extreme depth of the sea so far found. that of five miles. and
 find the pressure to the square foot on | the bottom AS water is comparative 1 lv inrOmrroSstbIp. a cubic foot of it
 weighs practically the same on the surface as at the bottom of the sen.
 In the ease of fresh water this Is sixty l two and half pounds. Salt water 1 weighs sli@hrly more. So all one has to do to ful ihp pressure due to the water at any depth is to multiply the 1 depth in feet by Siyty.two and half,
 and the answer is apparent at once in | pounds.
 At depth of five miles. the number
 of feet being 2GHO0 we have that nun
 bcr of cubic feet to multiply by sixty | two and a half. The answer is l,GjO.. ] 900 pounds. or S25 tons. to the square
 foot pressure. No known hollow yes seI can withstand this.
 While on the subject of increasing
 water pressure a number of interesting
 observations can be made in conncc-
 ton with air compressibility. Air is
 very compressible. the volume decreas- ] ing as the pressure increases. If a bot t]p is tightly corked it will contain air 1 at ordinary pressure of fifteen pounds 1 to tue square inch and that is the l pressure it excrts. Then tie weight | to the hottie and let it down in the sea by means of a string On bringing it
 to the top again it win be found that the stopper has been forced into the bottle by the water pressure. If the bottle is filled with water and stop
 Dcrcd and lot down no such thing takes place. showing that water is not com | prcssib,e to any great extent
 If by any means some air could be
 placed at the bottom of a sea five miles | dpcr it would not rise to the top. for it
 would be dpuSpr-that i% would weigh more to the cubic foot than water and the water would have to float on the air: hence no man knows if the bottom of our seas is wet or not.
 There is only one thing that would Drevcut the air from becoming this dense. and that is if it was cold enough
 it would !iqIefy. However, it is al-
 most imp1sstbIe-is, in fact, impossible
 for anything at the bottom of the sea to be colder than t degrees C., for if 1t
 got colder the water around it would become colder and larger and cOnse- nuentIv lighter and rise. and its place would he taken by degree water | NNitl MDIlH blll- tl4t yN.NNN 'O '--'-N tentncrature. So we have no argument against the suggestion, for the temper
 aturc at or below which air liqueieS is between 100 and 200 degrees below zero c.
 Some people seem to think that a stone thrown into the sea can sink only to a certain depth and is there ! held suspended on account of the pres sure of water A body immersed tn fluid is buOyed up only by the weight
 of the fluid displaced We have found
 that water is practically incOmpress-
 ibe. SD if the stone displaces a cubic
 foot of water that water weighs the same. or practically so, at the top or at the bottom of the sea. So the stone would be buoyed up only by that con stant force and would be carried down by its weight Thus the difference tn the forces would be always downward and the stone would sink to the bot tom.
 In fact, if the stone is at all con-
 pressible the tendency is for it to get
 heavier per unit volume as it goes down. for we have the same weight
 .. , r.,,,,rr,r rD1co TF will bp rpmpTl-