Re: i wanna look cute today...

On 2007-06-07, Rowland McDonnell <real-address-in-sig@xxxxxxxxxxxxxxx> wrote:
Whiskers <catwheezel@xxxxxxxxxxxxx> wrote:

[...]

Ah me - the good old days. NI is a bigger chunk now, but look how much
more the NHS is doing, and look at all those extra pensioners due to
extended life expectancy.

... and all those of us surviving on 'benefits' who'd have died off long
ago in the good old days.

I wonder about that one. Society was different back then - how *did* it
work? Fewer folk were cracked up in the fashion of thee an' me.

We'd have perished tragically and probably unpleasantly in the workhouse
or poor-law asylum, or in some freezing garret or sodden cellar.

[...]

People sometimes really did drain the radiator in cold weather, and
re-fill it with hot water in the morning to get the car started.

Coo! Although that'd not be done by wasting anti-freeze, am I right?
So most folk would have just plain water in there if they were doing
that.

Of course. 'Anti-freeze' was expensive, and could do strange things to
the insides of old engines.

On the other hand, those old engines were made of cast iron and really
needed some sort of corrosion inhibitor. What sort of problems turned
up? Seals going, and things like that?

Lime-scale is a pretty effective inhibitor ;))

If you have hard water, yes. Ah, limescale! Saved me from lead
exposure, has limescale: my parents house is literally plumbed into the
mains. Yep, the pipe from the mains outside to inside the house is
indeed made of plumbum.

I've lived in soft-water areas with lead plumbing; interesting stains on
the bath enamel, where the various lead and copper compounds get to show
their colours. I'm sure there are a lot of pre-60s houses which still
have lead in the no-man's-pipe section between the inside of the house and
the water-company's bits.

Anti-freeze could eat
through hoses and gaskets, and find leaks in radiators that were just too
small for plain water but would rapidly grow once the anti-freeze had
started a flow.

All the above still applies - but the cooling system parts are made of
different materials, and the available antifreeze is specified to work
with given materials after lots of testing and vehicle makers tell you
what to stick in.

Yes - and modern cars can go for months or even years without even a
top-up; cars made in the early '50s would normally carry a jerry-can of
water for topping up en route.

I gather that some manufacturers put `radiator leak stop' into the
cooling system of freshly-built vehicles, just in case.

If you use mostly the same water all the time in the
cooling system, the chemical reactions between the water and the iron
eventually reach a sort of balance-point.

Point.

Oxygenating the water by
draining it and then pouring it back would start the corrosion off again,
of course, and using fresh water each time would be even worse, but rust
doesn't seem to have been a major problem.

Righto. Our family's old cars were all air-cooled, IIRC - aside from
the ancient green Mini we once had, but I suspect that was always filled
with `the proper stuff', my dad being my dad.

That ancient green Mini was pretty high-tech and modern, you know! Was it
one of the early ones with visible door hinges and 'Hydralastic'
suspension?

Drained radiator-water would
usually be brown or red from the rust content, though - or black and oily,
quite often. I think there were 'inhibitors' or 'radiator aids' that you
could buy seperately from anti-freeze; such things had been developed in
the 19th century for use with steam boilers and hot-water heating systems,
but shoe-string drivers probably didn't go in for such fripperies.

Depends... My dad was a shoe-string driver, but he didn't approve of
having breakdowns, you know?

That's what tool-kits were for. Drivers who'd been through WWII were
often quite capable of stripping and re-building an engine or gear-box at
the side of the road - and the vehicles were built with that sort of thing
in mind. After all, with no-one shooting at you and being able to turn
the lights on, it was a doddle!

[...]

And then he added the condenser and efficiency
became better than a sick joke.

I thought the condenser came first;

Oh lordie, you might well be right - this is all from `the piled up
heaps of my memory' and I often get things the wrong way round until I
settle down to check.

But, erm... <cough> seems Watt didn't get to the high pressure first;
that was Capt. Dick:

<http://en.wikipedia.org/wiki/Richard_Trevithick#The_high_pressure_engin
e>

`He was not the first to think of so-called "strong steam", but he was
the first to make it work, in 1799.'

<http://en.wikipedia.org/wiki/Steam_engine>

Hero of Alexandria (1st century AD) was the first to demonstrate the
potential of steam under pressure (and simultaneously the principles of
the rocket and not far off the turbine)
(<http://www.history.rochester.edu/steam/hero/> item 50).

[...]

`Also in 1803, one of Trevithick's stationary pumping engines in use at
Greenwich exploded, killing 4 men. Although Trevithick considered the
explosion was caused by another case of careless operation rather than
design error, the incident was exploited relentlessly by his competitors
and promoters of the low-pressure engine, Watt and Boulton, who
highlighted the perceived risks of using high pressure steam.'

early Watt engines were still
'atmospheric', using steam only as a means of achieving vacuum.

Having started out in Cornwall, it has always irked me that so many
people are so sure that James Watt invented the steam engine and George
Stevenson invented railways and the steam locomotive. Trevithick was
first with all of them, although carts running on rails was a very ancient
idea, well known to miners and quarrymen (they were usually called
'tramways', probably derived from 'tramelled way' as the wheels are
'trammelled' by the rails).

Well, it's a `one step mod' and doesn't require new machining
techniques, so one would guess that the condenser was added before high
pressure working.

When the
high-pressure boiler and steam-expansion engine came along, the condenser
stage became almost irrelevent for most purposes

Umm... No, not really - you need the condenser to stop wasting steam.
If you want efficiency, you have a condenser.

There's a trade-off in fuel saved by re-using the water and getting the
benefit of greater vacuum at the cylinder exhaust valve, against the cost
of building and maintaining the extra hardware. Even road-going steam
vehicles seldom had condensers. Stationary engines rarely needed to bother
with water conservation so they don't have condensers either. Multi-stage
engines were a more cost-effective way to get maximum return from the
energy in the steam - each stage would operate at a lower pressure, using
the exhaust from the previous stage. That goes for modern power-station
turbines as much as it did for early reciprocating industrial engines. The
finally exhausted steam might be used to force a better draft in the flue,
or as a source of heat for an industrial process or for space heating.

and exhaust steam was
used to increase up-draft in the boiler chimney or just allowed to go to
waste. Even locomotive steam engines didn't bother to re-cycle the water
through a condenser.

Early ones, no. Later ones, yes.

I disagree - see above. Steam railways had water-towers at most stations
and fueling places precisely to replace the water that had been used;
agricultural traction engines and goods vehicles had to top up regularly
too - some even carried pumps and hoses to take water from ponds or
rivers.

[snip]

Seperating the condensing action from the hot cylinder was a very good
move; it still took a while for people to realise that the expansion of
steam from a high-pressure boiler was even more efficient that using only
the 'vacuum' effect. (And even longer for them to make a high pressure
boiler that didn't explode too easily).

Wasn't Watt the scoundrel who got a patent for the common crank for
'converting reciprocating motion into rotary motion'?

Nope, it was one of his employees, so Watt had to develop different
linkages.

I knew someone got away with it.

Well, I always read that it was one of his employees, but I `always
read' all sorts of other stuff that doesn't seem to be right either...

I've seen Victorian stationary engines
with all sorts of alternatives to the crank;

One good reason for not using a straightforward crank is that the motion
doesn't allow the forces on the piston to be purely in line with the
cylinder. If you happen to visit Quarry Bank Mill (just S. of
Manchester), you can have a look at a `non crank' steam engine in
operation - it's a lovely smooth action when it's adjusted right, but it
does take adjusting, apparently.

I can't find any images or descriptions of that engine with a quick web
search.

Internal combustion engines for cars and bikes seem to rely on the skirt
of the piston to absorb the lateral forces from having the con-rod hinging
at the piston; stationary engines have room for guide-rails so that the
piston rod and piston are kept aligned at all times and the crank is
hinged well clear of the piston, with the lateral forces absorbed by the
rail(s).

cams were popular, but it
seems surprising that the patent holder didn't think to challensge them on
the grounds that they were using precisely the same mechanical principle
as "his" crank but with a larger (and less efficient) bearing surface.

Friction doesn't depend on surface area, does it? Just loading - large
bearings needn't be less efficient, and they almost always last longer.

The most memorable alternative I've seen was a vertical gas engine
(internal combustion) fitted with a sort of rack-and-pinion device on the
piston-rod, driving a toothed wheel on the power stroke and ratcheting
under gravity for the return.

<goggles> in astonishment. Internal combustion, eh? Coo.

Yup.
*Bang*-rattle-thud-whirrr-whirrrr-whirrrr-whirrr-hissss-*Bang*-rattle-thud-
whirr- etc. The piston was only 'fired' when the flywheel fell below the
minimum speed set on the centrifugal regulator, so under no load the firing
strokes were a long way apart. That was in the old UMIST museum, in the
late 70s.

[...]

You can't run a boiler very effectively on hay and oats, which are much
easier to come by than coal or timber.

Hmm.... Ish. Coal can be dug up now. If you want hay or oats, you've
got to prepare a field, plant it, look after the crop until it's ready,
and so on.

Coal-mining is a big step away from farming cereals.

The reason for using an
atmospheric or steam engine is that it can do work that no muscle-based
power source could do, and can do it at least as reliably as a good
water-mill

Different unreliabilities: water mills can run out of water, depending
on the state of supply.

So can steam engines ;))

but without the restriction on location that a water-mill has -
so you have greater flexibilty than with any of the earlier power sources.
Nothing to do with substituting an engine for a horse.

How did they pump mines before steam engines? Surely they must have
done *some* pumping?

Animals and people with buckets, crude pumps, bucket-chains driven by
tread-mill or pony, pony-carts going up long gradual gradients to a
surface entrance possibly miles away, gravity if the workings had a valley
or sea-cliff near enough. All sorts of clever ideas were tried for getting
water up from really deep holes. The 'atmospheric engine' was a great
leap downwards for deep mining; it even enabled mines to go out under the
sea. Horses never really came into it with regard to deep mines - apart
from the pit ponies living down below to pull carts and things.

btw, ISTR that stationary steam engines were used to replace horses in
mines a bit - for hauling coal. ISTR hearing about various odd ways of
doing it until they got locomotives sorted.

Stationary steam engines were used for surface railways too, before it was
proved that locomotives were more effective (once you'd made the rails
strong enough to take the weight). Brunel built a 'vacuum railway' in
Devon, with stationary steam-driven vacuum pumps exhausting a pipe with a
sealed slot allowing carriages to be connected to a piston in the pipe
which was meant to be 'sucked' along by the vacuum. Sadly, rats and mice
took a liking to the greased leather seals (according to local legend) so
the system never lived up to its potential and the railway reverted to
cable operation until locomotives were brought in.
<http://www.capsu.org/library/documents/0025.html> "Atmospheric and
Pneumatic Railways".

Even today, water
power is still economically viable if you can locate your works
appropriately - hydro-electric power stations are the most obvious
example.

Yep.

Until powered spinning-machines came along there
was no over-whelming need for a power source that could operate
continuously for long periods,

Mine pumping was the first application, and while you can take breaks
from doing it, it does basically need doing continuously.

It's really a question of how much water can be accomodated before you get
problems with erosion or damage to plant, and how long it takes to clear
the surplus water if you've let it accumulate between work-shifts.

Not just that: there's also the efficiency problem of either letting
your boiler cool between pumping operations, which wastes heat and means
you've got a long start-up time to look forward to; or wasting even more
heat by keeping it hot. And then you have reliability problems brought
about by shutting down and starting up the engine. Best all round to
keep everything running constantly, unless you need to do maintenance or
similar.

True.

Certainly the Cornish tin-mines were pumped pretty continuously while they
were in production, and switching off the pumps could be calculated to
result in quantifiable accumulations of flood water that would rapidly
become too much for the installed pumps to restore to a 'working level'
within any practical amount of time; so re-opening any of those deep mines
is going to require a lot of extra pumping plant, if it ever happens at
all.

I shouldn't think it'll happen for a very long time. And modern pumping
plant is much more effective and efficient than the old stuff, innit? I
know nothing about it, but that's how engineering goes, right?

Until quite recently, some of the best hydraulic and pneumatic pumps were
bult in Camborne, Cornwall. Modern stuff is certainly a great deal more
efficient than a good old giant beam engine - but nowhere near as much
fun.

There's a purely financial calculation of the amount of pumping
capacity you can have in reserve compared with the cost of running
continously as against running intermittantly.

`!9 to the dozen' apparently refers to the number of bushels of coal
needed to shift a dozen `large units' (I forget) of water out of your
mine with a typical Newcomen setup. Or so I recall reading.

Factor in the other
production costs and the market price of the end product, and you get no
working mines in Cornwall for the foreseeable future.

Which is perhaps next year... but I suspect that they'll be getting tin
out of seawater or landfills sooner than re-open the Cornish mines.

Maybe not quite that, but the Malaysian mines can sell so cheaply, and the
market is so over-supplied, that Cornish mines can't compete - and
re-opening them would cost a fortune now that most of the plant has been
removed, almost all the above-ground parts are gone, and the workings have
been allowed to flood. There's more money in sending tourists down them
than getting ore out, these days. I think there is some extraction of
metals from the old spoil-heaps. Ah well, that industry did last from the
bronze age to the 20th century, which isn't a bad run.

[...]

True, true. Still, I gather that they liked to keep mine pumps pumping.
If you've got an engine, you're best off running it continuously if you
can for the sake of reliability and efficiency.

Yes indeed. Nuclear-powered mine pumps, anyone?

I bet they have 'em in France - well, it's all nuclear powered there,
innit? Just plug into the mains. *They* aren't too bothered about
rising fossil fuel prices, not for their electricity.

Perfectly logical. I still think there's a future for nuclear power in
the UK too; I can't see us matching our consumption to what we can get
from photo-voltaics and windmills any time soon.

[snip]

You'll probably approve of the Megalithic Yard then
<http://www.robertlomas.com/megyard/>. See also
<http://www.bwmaonline.com/index.html>.

It's a bit of a strange one that; I've read quite a lot about it, and
while the idea does seem to have something to it, I've read some
objections from various people. One is that one of the proposed methods
for defining the measure would produce a slightly different length at
different latitudes - but I don't see that as a problem, particularly.
Would Neolithic people have seen it as a problem for `X' to be different
in different places? I don't think so, not particularly - Europe got by
with lots of different official yards right up until metrication came
in. Why should neolithic folk not have done the same?

My thoughts agree. It's easy enough to compare lengths, weights, and
volumes, and agree on price adjustments accordingly. Our ancestors were
just as intelligent and resourceful as we are (if not more so), and
probaly knew a lot more about the natural world around them than we do,

Not just that, but they looked at the world differently to us. Who's
top say that the fact that the stone circle sets up a different `yard'
at different latitudes wasn't something that was *important* to them.

That is, they might well have thought that it was important to determine
the `natural sacred size' of *this* place before building anything
there, and if you did build something in a place, you had to use the
right yard for the place or it'd be `wrong', sort of thing?

The fact that the yards were different sizes in different places might
have been viewed as not so much a problem as simply a reflection of the
natural order of things which human beings had to fit in with if they
wanted things to work right, sort of thing.

Interesting thoughts. Why shouldn't things be different in different
places? Most things are anyway, which is what makes places different to
start with, so perhaps the thinking was along the lines you suggest.

so
I have no difficulty accepting the idea that those people could make very
accurate astronomical observations over very long periods even without
written records as such.

They had written records - maybe not words on paper sort of thing, but
certainly carvings on rock and if you're carving on rock, you might well
be doing the same on bits of wood and suchlike.

Come the time of `the druids' (as people say), they had *hundreds* of
cryptographic alphabets. I suspect that written records were used here
a very long time ago indeed - they just haven't survived.

It would have been well within the 'way things were' in those days for the
Romans to have destroyed what they didn't understand or see a use for; and
the natives might well have hidden or destroyed what they thought most
valuable just to stop the barbarian Romans from getting it. There are
more recent examples of that sort of thing going on.

I can't see why that author seems to think it would be so difficult to
reproduce a 'standard yard' measure simply by copying it;

Nor me; it's how it was done in historial times up until the 20th
century for all standard length measurement, wasn't it?

good enough for a
working copy for measuring cloth or timber or land, at any rate;

Quite.

not good
enough for quantum physics using stone-age technology, certainly, but then
in the stone age people weren't too bothered about that degree of
precision.

Well, no - people only started to worry about that sort of precision in
the 19th century, as far as I can tell. Prior to that, I expect `very
high precision' was written off as `unachievable by all but gods'.

Anyway, if you couldn't detect it with your own senses what use was it?

[...]

I find it rather comforting to think that people in the stone-age had a
system of measures that was more accurately based on observation of the
universe and nature than the 'metric system' we currently accept as
'standard'.

Umm... Last time I checked, the only part of the metric system that
wasn't derived from a quantum measurement was the kilogram, and they're
working on that one so they can replace the `standard kilo' in Paris
with something a bit more scientific.

Ah, but that's doing it backwards; the metre and all its dependents was
derived from "one ten-millionth of the great circle quadrant passing from
the north pole to the equator through Paris". Subsequent definitions
based on light or quantum mechanics are just re-expressions of that same
original unit of measure - which is in fact just an 'educated guess', as
the French revolutionaries had no way of even identifying exactly where
the north pole might actually be let alone measuring anything from it.
According to their intended definition, the metre as we have it is
actually smaller than it should be - but it's essentially arbitrary anyway
so that doesn't matter, apparently.
<http://www.straightdope.com/mailbag/mmetric.html>.

Current weights and measures are defined in relation to very precise and
tiny natural phenomena - but that isn't where they were derived from.

[snip]

In any case, 33000 is what one should
round 32580 to, if you want 2 SF.

... and base 10 ;))

<rolls eyes> Be like that.

<http://base12.org/>

Coo!

[snip]

I've read of attempts made by various people to jump the queue for a
Watt engine - they all got turned down, despite many of them offering
rather large dollops of cash.

Getting a reputation for accepting bribes is not a good way to start a
business.

Is it a bribe to work for money? Is it a bribe if you say `More money
will get the job done quicker'? I'm not sure about all that. More
money *does* get the job done quicker - is it bribery to pay your
workers triple time for Sunday working, for example?

Even unscrupulous businessmen have to be seen to uphold some
standards, if they're in it for the long haul - and setting up a
cutting-edge heavy engineering business isn't a short-term project.

I think he just liked telling these puffed up nouveau riche businessmen
where they could stick it; they were used to getting exactly what they
wanted with money and bullying, he had the power to tell 'em where to
get off, and he used it.

That's the feeling I've got, anyway.

I can see the attraction in that attitude :))

[...]

(and of course, it's
neighbourly to offer to share costs if two vehicles do happen to collide,
regardless of what the law says your obligations are - and much less
risky to do if it makes no difference to your 'legal' position).

There is that. I was involved in an RTA once: me on a bicycle, the
other chap in a car. I slammed into the side of his car head first
leaving his car with a couple of rather interesting dents (one fist, one
forearm - I shielded my head pretty well). Luckily, this was right
opposite the Manchester Royal Infirmary and a couple of student nurses
were just passing, having come off shift. So I got a quick checkup
before I was allowed to move from the tarmac, instructions to `Go to A&E
now, it's there <pointing>, and get a proper checkup for concussion.'

Thing is, the accident was sort of his fault and sort of mine; we'd both
made mistakes, and we both knew exactly what the mistake the other had
made, too. His car had a dented door, and I was more or less unharmed
along with my bike except for minor clothing damage and feeling slightly
stunned, so it was `Okay, let's just forget about it'.

(Sort of his fault and sort of mine? Okay: main road, cycle path down
the side of it, cycle path crosses side-street. Car turns off main road
down side-street just as I'm about to hurtle across the side street on
my bike flat out - neither of us had done used proper caution and we
were both hoping to get away with it. I suspect that I had right of
way, but maybe not. Anyway, I hit the front brake, the bike stopped
dead and never actually reached the tarmac of the side-street, and I
sailed through the air across the entire width of the side-street to hit
the car on the other side head-first - well, I'd got my arms involved so
I took the impact by punching the door with my right fist and protecting
my head with my left forearm braced ahead of me - or so me and the
driver reconstructed events from looking at the damage to his car and
how my hands and arms felt. Don't ask me how I managed it: I really
don't know)

I'm sure the various laws of thermodynamics and motion were not broken,
even if other things were.

[...]

If there were lots of bikes, I'm sure patterns would emerge and measures
could be devised. In the grand scheme of things it doesn't make any
difference to the four-wheelers if a few two-wheelers can make progress
through the gaps in a traffic-jam (it can be bloody annoying though!).

<shrug> I've never quite understood that - what's the problem?
Virtually all car drivers may have the same advantages simply by
switching to a motorycycle.

And we get hatred because we choose not to lock ourselves up in metal
cages...

It's envy, that's all: "he's getting somewhere and I'm not and I don't like
that". Plus the annoyance that "his bike probably cost less than my car
and is using less fuel getting somewhere than my car is getting nowhere",
and so on. And "he made a better choice than I did for this journey",
which is the worst thing of all about it :))

[...]

--
-- ^^^^^^^^^^
-- Whiskers
-- ~~~~~~~~~~
.

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