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sqj.1947.0035

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SECTION
Reported by "ALFRED"
THE use of millimeter wavelengths was touched
upon by Mr. E. M. Hickin in his Chairman's
address to the London Section on 20th October.
Showing how high-definition radar has called for
the use of shorter and shorter wavelengths, he
discussed some of the peculiar effects which appear
as the wavelength is decreased. In particular,
temperature gradients in the atmosphere are often
sufficient to bend radio waves to such an extent
that the earth appears flat. While this greatly
increases the 'range of transmission, false echoes
are often experienced from rain, though this, in
turn, leads to possible use of radar for storm
detection. As millimeter wavelengths are approached, troublesome absorptions are also caused
by the resonance of molecules of invisible .water
vapour or oxygen.
A good deal of research is being done on these
millimeter waves, and we are, indeed, rapidly
closing the gap between radio and infra-red rays.
Several interesting problems were discussed at
the next meeting on 4th November. One which
provoked a lively response was the relative merits
of steam and gas turbines for power stations.
This was introduced by Mr. D. A. Dewison, the
conclusion being reached that gas turbines are not
commercially justified at the moment except for
peak load operation.
Apart from meetings, however, the London
Section has been making full use of the excellent
weather during the early autumn, and on Sunday,
28th September, a party assembled at Leatherhead
for a day's ramble. A five-mile cross-country
walk in the direction of Box Hill brought the party
to an alfresco lunch, after which they returned to
Leatherhead via an alternative route.
East Midlands Get Going
Our newest Section, the East Midlands Section,
which was formally approved by the Council in
April of this year, is getting into its stride. During
the period January to May the tentative Committee organized three informal meetings and two
visits which provided useful experience. Several
formal meetings have now been arranged, two at
Loughborough College and one at Nottingham.
Initial difficulties are gradually being overcome,
and it is hoped that before the end of this Session
the Secretary will be able to wear his normal
benign expression instead of his present somewhat
harassed look!
A very enjoyable visit was made to the Rediffusion Organization in Nottingham. The enthusiasm of the Chief Engineer and his staff was
such that the visitors were kept in a state of continuous motion from 2 p.m. until 7 p.m. It is
noteworthy that the visitors numbered . two
stalwarts who had made the trip from Cambridge.
Another visit to a beet-sugar factory in the
Nottingham district was made memorable by the
fact that the visitors were invited to consume as
much sugar as they liked—but only on the
premises.
At the opening meeting of the present Session Mr.
Steven, the Chairman, opened the proceedings with
great zest and soon had the meeting in high good
humour. He hoped that the enthusiasm which
had been present during the informal meetings
prior to the official inauguration of the Section
would be well maintained and that the discussions
would continue on the same high level. The provision of tea at future Loughborough meetings
should attract even better audiences and help to
promote the feeling of good fellowship which is so •
characteristic of Students' meetings as a whole.
Cardiff Successes
After some early teething troubles the Cardiff
Section has started this Session on a very optimistic note. The Committee has been inundated
with offers of papers, and has, in fact, found itself
in the embarrassing position of having to ask some
of the authors to defer their papers until next
Irish Damask
Session.
Three of the papers read before the Section last
A very interesting visit was recently paid by the
Session gained awards. That by the Chairman, Northern Ireland Section to theBroadway Damask
Mr. S. R. Phelps, obtained a Student's Premium, Weaving Company. Starting with the raw material
while two other papers by Messrs. Passant and —the yarn—the entire processes of sorting, treatWarwick on "Metalclad Switchgear" and Tudor ing, winding, lashing, reeling and weaving were
Thomas on "Power Station Efficiency," each explained by the Manager, Mr. C. M'llveen in a
gained the Arthur Ellis prize, which is a Western magnificently conducted tour lasting three hours.
Centre award.
In the weaving shops exquisite damask was
Incidentally, the meeting place has been trans- examined on the looms, and of a special interest
ferred to the Electricity Demonstration Theatre in was some work being done for Princess Elizabeth's
Cardiff, which it is hoped will be more congenial. wedding gift from Northern Ireland. This work
I'also learn that in April a new type of meeting is has the unbelievably fine texture of 140 threads
to be held, as far as the Cardiff Section is con- to the inch and is a great credit to one of Ulster's
cerned, this being a joint meeting with the Students oldest industries.
and Graduates of the South Wales Branch of the
After viewing the massive finishing machinery
Institution of Mechanical Engineers. The paper and a water-cleansing plant which would have
will be given by one of the Cardiff members, Mr. done_ credit to any waterworks, the party ended
K. J. Davies, on "Boiler-House Instruments."
up in the showrooms. Here even the most
[28 ]
STUDENTS' QUARTERLY JOURNAL
hardened engineers gasped at the sheer beauty of
the coloured damask tablecloths, napkins, towels,
etc., which had been seen only a few sheds away
in the form of rough yarn.
Leeds Wants to Know More
A lively discussion followed the Chairman's
Address on the occasion of the first meeting of
the North Midland Section, particularly when one
member chose to differ with the author on the
merits of two types of colliery winding gear,
resulting in the two persons in question alternately
getting on their feet to substantiate their claims.
Undoubtedly a healthy state of affairs from a
discussion point of view, more of which would
improve our discussions.
The second meeting was one always looked
forward to by the Section—the Annual Exchange
Paper with Sheffield. This paper created a
precedent in the Section, since it was read by
Miss Joan Green, being in fact the paper of which
an abstract appeared in the September issue. The
paper was most interesting arid well presented, the
speaker proving her fair sex in domestic touches
put to replies to questions during the discussion.
The first visit of the Session was to Messrs.
Kershaw's of Leeds, manufacturers of cameras,
binoculars and cinematograph projectors, etc. A
most interesting afternoon was spent delving into
the intricacies of lens grinding and projector
mechanisms. On the commencement of the tour
the guide had some difficulty in impressing certain
sections of the party that there were more departments to inspect other than the first, which happened to be the comptometer room. The extraordinary versatility of these machines was so
delightfully demonstrated by their charming
operators that many members felt they ought not
to move on until they had really mastered the
technique themselves.
Twenty Questions at Manchester
I see that the North-Western Section is proposing to hold a "Twenty Questions" session to
follow the Brains Trust on the occasion of their
joint meeting with the Graduates of the I.M.E.
This should prove interesting, for apart from the
amusement which is caused to the audience it is
exceedingly stimulating to the imagination. At
first it might appear that such activities have little
to do with engineering, but the fact is that many
problems with which the engineer is faced can only
be solved by the exercise of a lively imagination,
capable of visualizing many possibilities, and able
to avoid being restricted to one track. This
faculty is essential in the game of Twenty Questions, as is well evidenced by some of the broadcast
sessions.
DECEMBER
1947
the three papers read by students, one gained a
Students' Premium, one was highly commended,
and the third had been published in the Students'
Journal. He pointed out that between the ages
of 24 and 30 men were technically in their prime,
Mr. Stephen with the Austin representatives at
LongbrUge (see p. 39).
and suggested that the older Graduates in particular should take the opportunity of making
original contributions in the form of papers to be
read at meetings.
The Editor paid a brief though very enjoyable
visit on 6th November, when Mr. C. E. Forrest
of the Central Electricity Board gave a most
interesting lecture on the Grid.
Sheffield Experiments
The Sheffield Section has arranged an ambitious
programme with no fewer than thirteen meetings
to be held in Sheffield, Chesterfield, Doncaster and
Rotherham. The Session opened with an address
by Mr. W. H. Foster, this year's Chairman, on the
subject of the "Whirling and Transvibration of
Shafts." This was followed by the now annual
Questions Evening, at which Mr. W. W. Grimes,
the Vice-Chairman of the Senior Section, acted as
a very competent question master.
An unusual paper was presented at Chesterfield
on 22nd November by Mr. K. Holling, who dealt
with "Electronic Aids to the Teaching of Electrical
Engineering." Demonstrations were given of
circuits for producing repeating transients, of a
half-coated fluorescent tube to illustrate the effect
of the coating, and a grid-controlled hot-cathode
rectifier circuit operating under inverted conditions. •
On 3rd March there is to be a lecture at Rotherham on "Statistical Methods in Electrical Engineering," a departure from purely electrical topics
which the Committee expects to prove a popular
experiment.
Enthusiasm at Rugby
Rugby continues to hold very successful and
enthusiastic meetings. At the opening meeting of
the Session the Past-Chairman of the Rugby SubCentre presented to Mr. T. E. Barany the prize
for the best paper read by a member of the
Students' Section. This paper was published in Discussions at Film Evenings
our June issue this year. The Past-Chairman, in
The Southern Section has also been in an experipresenting the prize, referred to the excellent mental frame of mind. Some time ago a suggesresults achieved during the inaugural Session. Of tion was received from a local Graduate of the
[ 29 ]
Section News
Institution of Mechanical Engineers that a profitable joint meeting could be held on the subject of
water power. The Committee was horrified to
discover that none of its members was qualified
to discuss this subject in any competent manner.
They therefore arranged a Film Evening, admirably
compered by the Hon. Secretary, Mr. Hewitt. The
evening commenced with "Water Power," which
detailed the elementary principles, followed by
"Power in the Highlands," which discusses the
sociological aspects. A third film entitled "Conquest of Dry Lands" showed how dry and arid
stretches of the Punjab had been made fertile by
the provision of suitable dams to permit the twofold improvements of irrigation and power supply,
while finally the well-known film "Valley of the
Tennessee" showed the possibilities of large-scale
application of scientific principles to prevent soil
erosion due to flooding.
An interesting innovation was the holding of
brief discussions while the reels were being
changed. This always introduces an awkward
hiatus into film evenings, and the experiment of
discussing thefilmjust shown proved an immediate
success.
Mr. Hewitt tells me that he has discovered the
secret of getting people to talk. The technique
seems to be to get up and put forward a theory
which is utterly and conceitedly wrong. 'This
provokes the shy members of the audience into
jumping up and shouting angrily "I don't agree."
Having said those three words they are in honour
bound to go on and tell why they don't agree—
which is what we want! •
COMMUNICATIONS IN HOMO SAPIENS
by R. S. ATKINS, Graduate*
ALL living things are equipped with some kind of
mechanism to indicate what i:is going on around
them. In man this has reached its highest stage
of development and consists of three parts, viz.:
Myelin sheath
Nerve asci?
Ferineurium
binding fibres
Epmeunum
binding
bundle! of
fibres
Fig. 1.—Cross-section of nerve fibre.
(1) Organs stimulated by external changes.
(2) Nerves to convey the stimuli, and
(3) A highly-developed brain to interpret them.
There are many kinds of organ which can send
stimuli. The taste buds are sensitive to dissolved
chemical substances, the olfactory organs respond
to gases and air-borne particles, the cells of the
retina are sensitive to light, while the skin has
several types of receptor, including those sensitive
to heat and pressure.
Should the stimuli call for action by the person
receiving them, a second type of nerve called a
"motor" nerve is required. These carry messages
from the brain to the muscles which move the
appropriate limb. Some processes, such as
digestion, go on automatically and cannot be controlled by the will. Food present in the stomach
stimulates nerves which communicate with the
brain. The action of muscles and glands then
proceed under the control of motor nerves.
• South Midland Section.
The Nerve
If an animal is dissected, the nerves may be
seen as thin white cords, leaving the.brain and
spinal cord. As they proceed through the body
or along the limbs, branches are given off and
these continue to divide and subdivide, until all
living parts of the animal are supplied.
The nerves from receptor organs (sensory
nerves) begin in them as fine terminal twigs, which
consist of single Derve fibres. These fibres are
devoid of any covering and may be compared to
wires, stripped of their insulation and secured in
a terminal block. As they leave the receptor, a
fatty tissue (the myelin sheath), and a membrane
(the neurilemma), covere and insulates each.
They form a bundle which is later joined by
bundles from other organs. The nerve now has
the appearance of a multicore telephone cable.
The motor nerves come from the brain and may
be included, with the sensory nerves, in the same
"cable." The combination is termed a mixed
nerve. Branches and twigs of motor nerves, however, end in muscles where the fibres also lose
their myelin sheath and investing membrane.
The latter becomes continuous with the membrane
covering the muscle while the terminal twigs end
in a mass of muscle tissue called the motor end
plate.
The Nerve Cell (Neuron)
Each nerve fibre, i.e. one strand in the nerve, is
part of a cell which has a nucleus surrounded by a
small mass of cytoplasm, like most other cells in
the body. But much of the material forms one or
two long processes extending to different parts of
the body as nerve fibres.
In sensory nerve cells one process, the dendron,
passes to the receptor organ: the other process,
the axon, projects in the opposite direction and
passes into the brain. A motor has one long
axon for relaying stimuli and usually several
shorter dendrons for receiving them. These are
shown at. Fig. 2 at the nucleus end of the cell.
[30 ]
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