SCIENTIFIC SUMMARY. 
429 
PHYSICS. 
Spheroidal State of Water, and Boiler Explosions. — Mr. W. F. Barrett, 
F.C.S., read a paper on the above subject at the meeting of the British 
Association at Brighton. He said : — On one occasion, some six years ago, I 
wanted to cool a red hot copper hall. For this purpose I plunged it into 
some water in which I had just washed my hands. The hot hall went in 
without any hissing or visible evolution of steam, and on removing it from 
the water it appeared as hot as before, in fact it remained brightly incan- 
descent, somewhat below the surface of the water. I was astonished to see 
this, as I did not know that the spheroidal state of water could he so readily 
produced and maintained by a body at this temperature. So I tried other 
red-hot bodies in the same water, and with the same result. I then threw 
away the soapy water and used plain water; the result was now quite 
different, the hissing was loud, and the evolution of steam copious. Hence 
the soapiness of the water was concerned in the phenomenon. Adding a 
little soap to the water immediately reproduced the result first noticed. 
Other bodies that dissolved in water were also tried, and the results are 
briefly these : — Albumen, glycerine, and organic liquids generally facilitate 
the acquisition of the spherical state, probably by increasing the cohesion of 
the water, whilst of course bodies such as ammonia, which readily yield 
vapour, have the same effect but not so marked. Oil shaken up or even 
placed on the surface of the water has the same effect as the soap. The 
best method of exhibiting the experiment is to pour a little of Plateau’s 
soap solution into a large beaker of water, and then, by means of a hooked 
wire, lower into the liquid a white-hot metal ball, some 2 lbs. weight, and 
of copper is best. The ball smoothly enters the water, and glows white-hot 
at a depth of a foot or more below the surface. Notwithstanding the con- 
siderable hydrostatic pressure it is seen to be surrounded by a shell of vapour, 
perhaps half-an-inch thick. This vapour shell is bounded by an envelope 
that resembles burnished silver, and has a most striking appearance. In 
fact the hot ball blows a soap bubble of steam, from the limiting surface of 
which the light is totally reflected. As the ball cools (mainly by radiation) 
the shell of vapour is seen to grow thinner, and finally collapse altogether, 
when immediately there follows a loud report, volumes of steam are pro- 
duced, and often the glass is broken. I have heard that traces of oil often 
get into the boilers of steam engines, and there can be no doubt that dis- 
solved organic matter often finds its way in. If in any way we increase 
the intensity of the water, we render it possible for a corroded boiler to give 
way under the pressure of the steam suddenly generated in the way I have 
indicated. 
The TJse of Steel Wire for Beep Sea Soundings. — Sir W. Thomson, 
F.B.S., read a paper on the above at the British Association in Brighton, in 
which he showed that the great difficulty of deep sea soundings consisted in 
the resistance of the water to the material used for letting down and raising 
the weight, and that the only way in which that difficulty had ever been 
overcome in very deep soundings had been by employing extremely heavy 
weights. When the depth of three hundred fathoms was passed, the ordi- 
