In message , The Natural Philosopher
writes
Fear of the dark is primordial superstition - ghosts and demons.

more like wolves and bears.

BUT actually I feel a lot safer in the dark than by day. I don't feel
illuminated as a potential target. Hiding is easy. Find deep shadow and
be still.

Any attacker must then use a light..

Or have better eyesight or be sitting in the shadows watching your
movements and waiting for you to be close enough.

(Don't get me wrong, I worked for two decades at night and became used
to using my ears as much as my eyes to warn me of anything to concern
me.)

--
Simon

12) The Second Rule of Expectations
An EXPECTATION is a Premeditated resentment.

On 15/03/2013 01:41, Arfa Daily wrote:
....
A very interesting reference document. It is now in my favourites. As to
driving in the dark, I think a lot depends on your age. I don't know if
it is a general physical degradation in your night time vision, or just
a perceived thing. What I do know is that I am a lot less comfortable
now driving in the dark, than I was 20 years ago....

It is age related. I read somewhere that, by the time you are 80, you
have night vision equivalent to a 20 year old wearing dark sunglasses.

Colin Bignell

In article ,
Nightjar wrote:
On 15/03/2013 01:41, Arfa Daily wrote:
...
A very interesting reference document. It is now in my favourites. As to
driving in the dark, I think a lot depends on your age. I don't know if
it is a general physical degradation in your night time vision, or just
a perceived thing. What I do know is that I am a lot less comfortable
now driving in the dark, than I was 20 years ago....

It is age related. I read somewhere that, by the time you are 80, you
have night vision equivalent to a 20 year old wearing dark sunglasses.

and another problem is that cataracts tend to cause flare from bright
lights.

--
From KT24

Using a RISC OS computer running v5.18

On 15/03/2013 05:26, usenet2012 wrote:
Or have better eyesight or be sitting in the shadows watching your
movements and waiting for you to be close enough.

Or have an infra-red night viewing device.

Andy

"Nightjar" wrote in message
...
On 15/03/2013 01:41, Arfa Daily wrote:
...
A very interesting reference document. It is now in my favourites. As to
driving in the dark, I think a lot depends on your age. I don't know if
it is a general physical degradation in your night time vision, or just
a perceived thing. What I do know is that I am a lot less comfortable
now driving in the dark, than I was 20 years ago....

It is age related. I read somewhere that, by the time you are 80, you have
night vision equivalent to a 20 year old wearing dark sunglasses.

Colin Bignell


Considering that many people drive well into their 70s now, I wonder whether
this factor is taken into consideration when designing these 'new' lighting
systems ? It would be interesting for the night-time accident studies to
look into the ages of the victims. Do you have any reference for for your
'sunglasses' nugget ?

Arfa

"charles" wrote in message
...
In article ,
Nightjar wrote:
On 15/03/2013 01:41, Arfa Daily wrote:
...
A very interesting reference document. It is now in my favourites. As
to
driving in the dark, I think a lot depends on your age. I don't know if
it is a general physical degradation in your night time vision, or just
a perceived thing. What I do know is that I am a lot less comfortable
now driving in the dark, than I was 20 years ago....

It is age related. I read somewhere that, by the time you are 80, you
have night vision equivalent to a 20 year old wearing dark sunglasses.

and another problem is that cataracts tend to cause flare from bright
lights.

--
From KT24

Using a RISC OS computer running v5.18



Again, something that many of us will suffer without it impacting on our
general life, and without it being a big issue - at least in the earlier
stages - as long as stuff is well and properly lit at night. At the moment,
I still have a LPS light standard right outside my house. I would guess that
it is about 4 metres tall. It has a 35 watt lamp fitted. With the 'turn-off'
regime that we have suffered in the street, it is the only light for some
distance in both directions. However, looking out of the window last night,
everything was clearly illuminated in both directions up and down the
street, including all of the gardens across the street, which I think is an
important security 'feature'. At the other end of the street, where the
light standards have been replaced, these are now some 2 metres taller, so
immediately change the whole character of the street. They just look 'wrong'
in an urban street of houses type setting. Height wise, they would be ok on
a main road.

The light from them does not light the street in the same 'pleasant' way -
even setting aside the monochromatic and poor CRI nature of sodium - as the
existing lights. The light is concentrated to the point where there is none
in gardens. I guess that this is because the optics have been designed to
squeeze as much light out of the mono-planar LEDs as possible, to justify
the efficiency claims that are made for them ...

Arfa

"usenet2012" wrote in message
...
In message , The Natural Philosopher
writes
Fear of the dark is primordial superstition - ghosts and demons.

more like wolves and bears.

BUT actually I feel a lot safer in the dark than by day. I don't feel
illuminated as a potential target. Hiding is easy. Find deep shadow and be
still.

Any attacker must then use a light..

Or have better eyesight or be sitting in the shadows watching your
movements and waiting for you to be close enough.

(Don't get me wrong, I worked for two decades at night and became used to
using my ears as much as my eyes to warn me of anything to concern me.)

--
Simon

12) The Second Rule of Expectations
An EXPECTATION is a Premeditated resentment.


+1

Given what Colin said above about night time vision deteriorating with age,
and the fact that any potential attacker is likely to be quite young, and
have been 'laying in wait' long enough for their eyes to become fully dark
adjusted, I think that i would rather have good lighting in the first place,
than pools of dark to skulk in, in the fond hope that I wouldn't be seen ...
!

Arfa

On Fri, 15 Mar 2013 09:10:23 -0000, "Arfa Daily"
wrote:



"usenet2012" wrote in message
...
In message , The Natural Philosopher
writes
Fear of the dark is primordial superstition - ghosts and demons.

more like wolves and bears.

BUT actually I feel a lot safer in the dark than by day. I don't feel
illuminated as a potential target. Hiding is easy. Find deep shadow and be
still.

Any attacker must then use a light..

Or have better eyesight or be sitting in the shadows watching your
movements and waiting for you to be close enough.

(Don't get me wrong, I worked for two decades at night and became used to
using my ears as much as my eyes to warn me of anything to concern me.)


+1

Given what Colin said above about night time vision deteriorating with age,
and the fact that any potential attacker is likely to be quite young, and
have been 'laying in wait' long enough for their eyes to become fully dark
adjusted, I think that i would rather have good lighting in the first place,
than pools of dark to skulk in, in the fond hope that I wouldn't be seen ...

You lot must have lots of enemies if you're so worried about being
attacked ;-)
--
(\__/) M.
(='.'=) If a man stands in a forest and no woman is around
(")_(") is he still wrong?

On 15/03/2013 08:52, Arfa Daily wrote:


"Nightjar" wrote in message
...
On 15/03/2013 01:41, Arfa Daily wrote:
...
A very interesting reference document. It is now in my favourites. As to
driving in the dark, I think a lot depends on your age. I don't know if
it is a general physical degradation in your night time vision, or just
a perceived thing. What I do know is that I am a lot less comfortable
now driving in the dark, than I was 20 years ago....

It is age related. I read somewhere that, by the time you are 80, you
have night vision equivalent to a 20 year old wearing dark sunglasses.

Colin Bignell


Considering that many people drive well into their 70s now, I wonder
whether this factor is taken into consideration when designing these
'new' lighting systems ? It would be interesting for the night-time
accident studies to look into the ages of the victims. Do you have any
reference for for your 'sunglasses' nugget ?

Unfortunately, I don't now recall where I read it.

Colin Bignell

On 15/03/13 08:03, Nightjar wrote:
On 15/03/2013 01:41, Arfa Daily wrote:
....
A very interesting reference document. It is now in my favourites. As to
driving in the dark, I think a lot depends on your age. I don't know if
it is a general physical degradation in your night time vision, or just
a perceived thing. What I do know is that I am a lot less comfortable
now driving in the dark, than I was 20 years ago....

It is age related. I read somewhere that, by the time you are 80, you
have night vision equivalent to a 20 year old wearing dark sunglasses.

Pupil size?
Invest Ophthalmol Vis Sci. 1994 Mar;35(3):1132-7.
Factors affecting light-adapted pupil size in normal human subjects.
Winn B, Whitaker D, Elliott DB, Phillips NJ.
Source

Department of Vision Sciences, Glasgow Caledonian University, United
Kingdom.
Abstract
PURPOSE:

To investigate the effect of age, gender, refractive error, and iris
color on light-adapted pupil size in humans.
METHODS:

Pupil diameters of 91 subjects (age range, 17 to 83 years) with normal,
healthy eyes were measured using an objective infrared-based continuous
recording technique. Five photopic ocular illuminance levels were used
(2.15 to 1050 lumens m-2), and the accommodative status of each subject
was precisely controlled at a constant level.
RESULTS:

Pupil size decreased linearly as a function of age at all illuminance
levels. Even at the highest illuminance level, there was still a
significant effect of age upon pupil size. The rate of change of pupil
diameter with age decreased from 0.043 mm per year at the lowest
illuminance level to 0.015 mm per year at the highest. In addition, the
variability between pupil sizes of subjects of the same age decreased by
a factor of approximately two as luminance was increased over the range
investigated. Pupil size was found to be independent of gender,
refractive error, or iris color (P 0.1).
CONCLUSIONS:

Of the factors investigated, only chronologic age had a significant
effect on the size of the pupil. The phenomenon of senile miosis is
present over a wide range of ocular illuminance levels.

http://www.ncbi.nlm.nih.gov/pubmed/8125724


--
djc

On 15/03/2013 12:32, djc wrote:
On 15/03/13 08:03, Nightjar wrote:
On 15/03/2013 01:41, Arfa Daily wrote:
....
A very interesting reference document. It is now in my favourites. As to
driving in the dark, I think a lot depends on your age. I don't know if
it is a general physical degradation in your night time vision, or just
a perceived thing. What I do know is that I am a lot less comfortable
now driving in the dark, than I was 20 years ago....

It is age related. I read somewhere that, by the time you are 80, you
have night vision equivalent to a 20 year old wearing dark sunglasses.

Pupil size?
Invest Ophthalmol Vis Sci. 1994 Mar;35(3):1132-7.
Factors affecting light-adapted pupil size in normal human subjects.
Winn B, Whitaker D, Elliott DB, Phillips NJ.
Source

Department of Vision Sciences, Glasgow Caledonian University, United
Kingdom.
Abstract
PURPOSE:

To investigate the effect of age, gender, refractive error, and iris
color on light-adapted pupil size in humans.
METHODS:

Pupil diameters of 91 subjects (age range, 17 to 83 years) with normal,
healthy eyes were measured using an objective infrared-based continuous
recording technique. Five photopic ocular illuminance levels were used
(2.15 to 1050 lumens m-2), and the accommodative status of each subject
was precisely controlled at a constant level.
RESULTS:

Pupil size decreased linearly as a function of age at all illuminance
levels. Even at the highest illuminance level, there was still a
significant effect of age upon pupil size. The rate of change of pupil
diameter with age decreased from 0.043 mm per year at the lowest
illuminance level to 0.015 mm per year at the highest. In addition, the
variability between pupil sizes of subjects of the same age decreased by
a factor of approximately two as luminance was increased over the range
investigated. Pupil size was found to be independent of gender,
refractive error, or iris color (P 0.1).
CONCLUSIONS:

Of the factors investigated, only chronologic age had a significant
effect on the size of the pupil. The phenomenon of senile miosis is
present over a wide range of ocular illuminance levels.

http://www.ncbi.nlm.nih.gov/pubmed/8125724


It might be interesting to read this paper:

http://psychsocgerontology.oxfordjou.../S281.abstract

If only we ordinary mortals could do so. Any gods here with access who
could tell us if it is relevant?

There are several diseases/disorders which affect sight significantly -
but are frequently ignored (e.g. in not being on the DVLA notification
list and not being in what doctors tell patients).

I found this site interesting:

http://www.nhtsa.gov/people/injury/r...s/Foreword.htm

Obviously Section 14 is of particular relevance to this discussion.

--
Rod

On 15/03/2013 12:51, polygonum wrote:


And Section 2!

--
Rod

On 15/03/2013 13:46, Jethro_uk wrote:


On the M40, after High Wycombe westbound (J6 IIRC) where the road comes
out of the high-cliffed bit and starts to go downhill, the road lights
finish. Invariably there's a drop in speed of all the traffic by about 20
mph.

Nothing to do with the Stokenchurch-to-Lewknor fogbank? :-)

Do they speed up when coming from unlit into lit areas?

I rather agree but I often find people's choice of driving speed
perplexing. If you go into London on the M40/A40 it is surprising how
many vehicles slow down well below 70 ages before the speed limit
actually drops. And then, once in the 50 mph bit, actually speed up to
60 or so. Similarly in reverse - doing 40 in the 30 but, but staying
down at 50/60 when limit goes back to 70.

--
Rod

On 15/03/2013 14:37, Huge wrote:
On 2013-03-15, Nightjar wrote:
On 15/03/2013 08:52, Arfa Daily wrote:


"Nightjar" wrote in message
...
On 15/03/2013 01:41, Arfa Daily wrote:
...
A very interesting reference document. It is now in my favourites. As to
driving in the dark, I think a lot depends on your age. I don't know if
it is a general physical degradation in your night time vision, or just
a perceived thing. What I do know is that I am a lot less comfortable
now driving in the dark, than I was 20 years ago....

It is age related. I read somewhere that, by the time you are 80, you
have night vision equivalent to a 20 year old wearing dark sunglasses.

Colin Bignell


Considering that many people drive well into their 70s now, I wonder
whether this factor is taken into consideration when designing these
'new' lighting systems ? It would be interesting for the night-time
accident studies to look into the ages of the victims. Do you have any
reference for for your 'sunglasses' nugget ?

Unfortunately, I don't now recall where I read it.

That'll be your age.

I had the prefect response to that, but I've forgotten it.

Colin Bignell

"Huge" wrote in message
...
On 2013-03-15, Nightjar wrote:
On 15/03/2013 14:37, Huge wrote:
On 2013-03-15, Nightjar wrote:
On 15/03/2013 08:52, Arfa Daily wrote:


"Nightjar" wrote in message
...
On 15/03/2013 01:41, Arfa Daily wrote:
...
A very interesting reference document. It is now in my favourites.
As to
driving in the dark, I think a lot depends on your age. I don't know
if
it is a general physical degradation in your night time vision, or
just
a perceived thing. What I do know is that I am a lot less
comfortable
now driving in the dark, than I was 20 years ago....

It is age related. I read somewhere that, by the time you are 80, you
have night vision equivalent to a 20 year old wearing dark
sunglasses.

Colin Bignell


Considering that many people drive well into their 70s now, I wonder
whether this factor is taken into consideration when designing these
'new' lighting systems ? It would be interesting for the night-time
accident studies to look into the ages of the victims. Do you have any
reference for for your 'sunglasses' nugget ?

Unfortunately, I don't now recall where I read it.

That'll be your age.

I had the prefect response to that, but I've forgotten it.

I'm sorry, but who are you, again?

Who started this thread, anyway ...

Arfa




--
Today is Prickle-Prickle, the 1st day of Discord in the YOLD 3179
"Jesus died for somebody's sins, but not mine"

in 1212518 20130315 115638 Nightjar wrote:
On 15/03/2013 08:52, Arfa Daily wrote:


"Nightjar" wrote in message
...
On 15/03/2013 01:41, Arfa Daily wrote:
...
A very interesting reference document. It is now in my favourites. As to
driving in the dark, I think a lot depends on your age. I don't know if
it is a general physical degradation in your night time vision, or just
a perceived thing. What I do know is that I am a lot less comfortable
now driving in the dark, than I was 20 years ago....

It is age related. I read somewhere that, by the time you are 80, you
have night vision equivalent to a 20 year old wearing dark sunglasses.

Colin Bignell


Considering that many people drive well into their 70s now, I wonder
whether this factor is taken into consideration when designing these
'new' lighting systems ? It would be interesting for the night-time
accident studies to look into the ages of the victims. Do you have any
reference for for your 'sunglasses' nugget ?

Unfortunately, I don't now recall where I read it.

I used to enjoy driving at night, but for the last few years (I'm nearly 72) I have
found it extremely difficult, even though my optician says my eyes are fine for
driving.

Bob Martin wrote:
in 1212518 20130315 115638 Nightjar
wrote:
On 15/03/2013 08:52, Arfa Daily wrote:


"Nightjar" wrote in message
...
On 15/03/2013 01:41, Arfa Daily wrote:
...
A very interesting reference document. It is now in my
favourites. As to driving in the dark, I think a lot depends
on your age. I don't know if it is a general physical
degradation in your night time vision, or just a perceived
thing. What I do know is that I am a lot less comfortable now
driving in the dark, than I was 20 years ago....

It is age related. I read somewhere that, by the time you are
80, you have night vision equivalent to a 20 year old wearing
dark sunglasses.

Colin Bignell


Considering that many people drive well into their 70s now, I
wonder whether this factor is taken into consideration when
designing these 'new' lighting systems ? It would be interesting
for the night-time accident studies to look into the ages of the
victims. Do you have any reference for for your 'sunglasses'
nugget ?

Unfortunately, I don't now recall where I read it.

I used to enjoy driving at night, but for the last few years (I'm
nearly 72) I have found it extremely difficult, even though my
optician says my eyes are fine for driving.

I am nearly 72?

--
Adam

in 1212818 20130316 165459 "ARW" wrote:
Bob Martin wrote:
in 1212518 20130315 115638 Nightjar
wrote:
On 15/03/2013 08:52, Arfa Daily wrote:


"Nightjar" wrote in message
...
On 15/03/2013 01:41, Arfa Daily wrote:
...
A very interesting reference document. It is now in my
favourites. As to driving in the dark, I think a lot depends
on your age. I don't know if it is a general physical
degradation in your night time vision, or just a perceived
thing. What I do know is that I am a lot less comfortable now
driving in the dark, than I was 20 years ago....

It is age related. I read somewhere that, by the time you are
80, you have night vision equivalent to a 20 year old wearing
dark sunglasses.

Colin Bignell


Considering that many people drive well into their 70s now, I
wonder whether this factor is taken into consideration when
designing these 'new' lighting systems ? It would be interesting
for the night-time accident studies to look into the ages of the
victims. Do you have any reference for for your 'sunglasses'
nugget ?

Unfortunately, I don't now recall where I read it.

I used to enjoy driving at night, but for the last few years (I'm
nearly 72) I have found it extremely difficult, even though my
optician says my eyes are fine for driving.

I am nearly 72?

OK, I'm seventy-one-and-three-quarters ;-)

On Mar 17, 7:49*am, Bob Martin wrote:
in 1212818 20130316 165459 "ARW" wrote:





Bob Martin wrote:
in 1212518 20130315 115638 Nightjar
wrote:
On 15/03/2013 08:52, Arfa Daily wrote:

"Nightjar" wrote in message
m...
On 15/03/2013 01:41, Arfa Daily wrote:
...
A very interesting reference document. It is now in my
favourites. As to driving in the dark, I think a lot depends
on your age. I don't know if it is a general physical
degradation in your night time vision, or just a perceived
thing. What I do know is that I am a lot less comfortable now
driving in the dark, than I was 20 years ago....

It is age related. I read somewhere that, by the time you are
80, you have night vision equivalent to a 20 year old wearing
dark sunglasses.

Colin Bignell

Considering that many people drive well into their 70s now, I
wonder whether this factor is taken into consideration when
designing these 'new' lighting systems ? It would be interesting
for the night-time accident studies to look into the ages of the
victims. Do you have any reference for for your 'sunglasses'
nugget ?

Unfortunately, I don't now recall where I read it.

I used to enjoy driving at night, but for the last few years (I'm
nearly 72) I have found it extremely difficult, even though my
optician says my eyes are fine for driving.

I am nearly 72?

OK, I'm seventy-one-and-three-quarters *;-)

ITYM 71.75 ..... ya daft old bugger ;)

Jim K

Bob Martin wrote:
in 1212818 20130316 165459 "ARW"
wrote:
Bob Martin wrote:
in 1212518 20130315 115638 Nightjar
wrote:
On 15/03/2013 08:52, Arfa Daily wrote:


"Nightjar" wrote in message
...
On 15/03/2013 01:41, Arfa Daily wrote:
...
A very interesting reference document. It is now in my
favourites. As to driving in the dark, I think a lot
depends on your age. I don't know if it is a general
physical degradation in your night time vision, or just a
perceived thing. What I do know is that I am a lot less
comfortable now driving in the dark, than I was 20 years
ago....

It is age related. I read somewhere that, by the time you
are 80, you have night vision equivalent to a 20 year old
wearing dark sunglasses.

Colin Bignell


Considering that many people drive well into their 70s now, I
wonder whether this factor is taken into consideration when
designing these 'new' lighting systems ? It would be
interesting for the night-time accident studies to look into
the ages of the victims. Do you have any reference for for
your 'sunglasses' nugget ?

Unfortunately, I don't now recall where I read it.

I used to enjoy driving at night, but for the last few years (I'm
nearly 72) I have found it extremely difficult, even though my
optician says my eyes are fine for driving.

I am nearly 72?

OK, I'm seventy-one-and-three-quarters ;-)

Women always do that when you ask how old thier child is. You get answers
such as "5 in October"

--
Adam

On 17/03/2013 08:13, Jim K wrote:
OK, I'm seventy-one-and-three-quarters;-)
ITYM 71.75 ..... ya daft old bugger ;)

If he says 71 and three quarters I take it that is accurate to a month
or so - more than 71 and a half, less than 72.

If you say 71.75 I take it not as low as 71.74 nor as high as 71.76...

Andy

On 18/03/2013 10:19, Jethro_uk wrote:
On Fri, 15 Mar 2013 13:55:05 +0000, polygonum wrote:

On 15/03/2013 13:46, Jethro_uk wrote:

On the M40, after High Wycombe westbound (J6 IIRC) where the road comes
out of the high-cliffed bit and starts to go downhill, the road lights
finish. Invariably there's a drop in speed of all the traffic by about
20 mph.

Nothing to do with the Stokenchurch-to-Lewknor fogbank? :-)

Doesn't help

Do they speed up when coming from unlit into lit areas?


Actually, yes. Although the incline of the journey in the opposite
direction might have some bearing. But many times I have driven up the
hill, and noticed traffic speeds increase by about 20mph ...

I rather agree but I often find people's choice of driving speed
perplexing. If you go into London on the M40/A40 it is surprising how
many vehicles slow down well below 70 ages before the speed limit
actually drops. And then, once in the 50 mph bit, actually speed up to
60 or so. Similarly in reverse - doing 40 in the 30 but, but staying
down at 50/60 when limit goes back to 70.

One thing I have noticed since having a car with cruise control is that
the choice of speed of the car in front is invariably 1mph less than
mine ...

Oh yes!

Used to have a Saab turbo 16V - that would do almost all motorway work
in fifth, up hill and down dale, without any noticeable slowing down. CC
really highlighted how other vehicles changed speed a lot. I guess some
of that was drivers not using/having CC, and some simply car engines not
able to make it up hills so apparently effortlessly.

--
Rod

On Sat, 16 Mar 2013 16:54:59 -0000, "ARW"
wrote:

I am nearly 72?

Poor old bugger, Adam, forgotten your age again?
You're 71, dear.

On Mon, 18 Mar 2013 10:19:08 GMT Jethro_uk wrote :
One thing I have noticed since having a car with cruise control is that
the choice of speed of the car in front is invariably 1mph less than
mine ...

Roll on radar cruise control being the norm.

--
Tony Bryer, Greentram: 'Software to build on',
Melbourne, Australia www.greentram.com

In article ,
polygonum wrote:
Used to have a Saab turbo 16V - that would do almost all motorway work
in fifth, up hill and down dale, without any noticeable slowing down. CC
really highlighted how other vehicles changed speed a lot. I guess some
of that was drivers not using/having CC, and some simply car engines not
able to make it up hills so apparently effortlessly.

If it will climb any hill in top gear, the gearing's too low for best MPG.

--
*Can fat people go skinny-dipping?

Dave Plowman London SW
To e-mail, change noise into sound.

On 18/03/2013 10:47, Dave Plowman (News) wrote:
In article ,
polygonum wrote:
Used to have a Saab turbo 16V - that would do almost all motorway work
in fifth, up hill and down dale, without any noticeable slowing down. CC
really highlighted how other vehicles changed speed a lot. I guess some
of that was drivers not using/having CC, and some simply car engines not
able to make it up hills so apparently effortlessly.

If it will climb any hill in top gear, the gearing's too low for best MPG.

I can't think of a motorway hill it couldn't manage. It was the turbo
that made a huge difference. Of course, on lesser roads, I needed to
drop from fifth.

--
Rod

In article ,
polygonum wrote:
If it will climb any hill in top gear, the gearing's too low for best
MPG.

I can't think of a motorway hill it couldn't manage.

Shap?

--
*I dropped out of communism class because of lousy Marx.*

Dave Plowman London SW
To e-mail, change noise into sound.

On 18/03/2013 12:47, Dave Plowman (News) wrote:
In article ,
polygonum wrote:
If it will climb any hill in top gear, the gearing's too low for best
MPG.

I can't think of a motorway hill it couldn't manage.

Shap?

I don't remember specifically, but have certainly driven up and down
M6/M74 and don't remember any thoughts of "wow - had to change down
there" - but a few years and crappy memory could have got in the way. :-)

At least most of the time, except when speed necessarily dropped due to
traffic/roadworks/etc., all I needed to do was press the accelerator
down a bit more.

--
Rod

On 18/03/2013 10:23, polygonum wrote:
Used to have a Saab turbo 16V - that would do almost all motorway work
in fifth, up hill and down dale, without any noticeable slowing down. CC
really highlighted how other vehicles changed speed a lot. I guess some
of that was drivers not using/having CC, and some simply car engines not
able to make it up hills so apparently effortlessly.

I was in France once, driving along the motorway out of the port, and
all the traffic slowed down. What's going on? I thought, and slowed to
match... must be a speed limit... oh of course, hill and small diesels!
Back up to speed, and still in 5th.

BTW Dave, mine is geared for max top speed instead. Probably a little
low for economy, but that wasn't their aim.

Andy

On 18/03/2013 15:29, Jethro_uk wrote:
On Mon, 18 Mar 2013 10:47:11 +0000, Dave Plowman (News) wrote:

In article ,
polygonum wrote:
Used to have a Saab turbo 16V - that would do almost all motorway work
in fifth, up hill and down dale, without any noticeable slowing down.
CC really highlighted how other vehicles changed speed a lot. I guess
some of that was drivers not using/having CC, and some simply car
engines not able to make it up hills so apparently effortlessly.

If it will climb any hill in top gear, the gearing's too low for best
MPG.

Really cruise control is best served with an automatic box

Actually, I found that with the Saab, it worked pretty well (was
manual), but that was because fifth was so capable. I can't help but
think that the optimum combination would be a CVT with CC. (Shame so few
CVTs seem to be much good other than in 'shoppers'.)

--
Rod

On Wednesday, March 13, 2013 2:28:00 AM UTC, Arfa Daily wrote:
Has anyone got any long-term experience of LED street light replacements ?

They've just started replacing all the lamposts in my street, with a lot

fewer - and 2 metre taller - lamposts fitted with LED luminaires. We had a

circular from the contractors / council come through the door, which made

some claims about how much money they had already saved by switching off

half or more of all the lights in domestic streets, and just about all of

the lights on the main roads. They then went on to make some further claims

about how much more money they were going to save as a result of fitting

these new LED based lights. Both myself, and my neighbour, who is an

industrial electrician of many years experience, think that the claims being

made are fairly outrageous, and that the numbers, as presented, don't stack

up. The previous lights were low pressure sodium, and when the guy came to

replace a faulty lamp in the one between our houses, my neighbour asked him

what the power rating was. It was 35 watts, which really isn't a lot. OK, I

know that there will be some losses in the ballast, so let's add another few

watts to that and call it 40 watts all in.



Looking on the 'net, it seems that the LED equivalents start at about 28

watts, with a further 9 watts lost in the driving engine, so 37 watts, which

doesn't seem like a whole bunch different from the sodiums that we had

before. Apparently, the new ones are going to dim down at 2 am, so that

will, admittedly, save a bit more, but it still seems to me that the figures

are being presented in a less-than-straightforward manner, which seems to be

the way of all government propaganda, both central and local, nowadays.



Last night, they switched on some of the new ones at the other end of the

street, so tonight, I drove round to take a look. My neighbour said that

when his missus came home last night, she reckoned that they had dazzled

her. I could see what she meant. They were actually quite unpleasant to

drive under. It seems that they have given them a wide dispersion angle in

an effort, when coupled with the extra height over the original lights, to

fill in the pools of gloom left by setting fewer of them further apart. The

result is that they shine down into your face from quite a distance away.



They also claimed that night time colour rendition would be better, because

the replacement lights were going to be white. Well, they *are* white - sort

of. But actually, the light is quite a creamy colour. But setting that

aside, I really don't see why night time colour rendition is of any

importance, over the fact that one of the main reasons that sodium lighting

was first introduced, was because it improved visibility in fog by a huge

amount. I can still remember driving in fog when street lighting was

predominantly by conventional linear white fluorescents, and it was a much

improved situation when the yellow sodium lighting was introduced.



I'm interested in any thoughts, facts, experience or observations that

anyone might have.



Arfa

A bit late to this thread, but we have noticed that you cannot distinguish between a bright white LED street lamp reflecting of something and a vehicle coming down the road but just out of sight.
This actually causes one to be slightly more cautious about what might be approaching, but equally it could distract your attention from something else that mattered.
Simon.

In message , polygonum
writes
On 18/03/2013 10:47, Dave Plowman (News) wrote:
In article ,
polygonum wrote:
Used to have a Saab turbo 16V - that would do almost all motorway work
in fifth, up hill and down dale, without any noticeable slowing down. CC
really highlighted how other vehicles changed speed a lot. I guess some
of that was drivers not using/having CC, and some simply car engines not
able to make it up hills so apparently effortlessly.

If it will climb any hill in top gear, the gearing's too low for best MPG.

I can't think of a motorway hill it couldn't manage. It was the turbo
that made a huge difference. Of course, on lesser roads, I needed to
drop from fifth.

I had the ultimate embarrassment: driving a Morgan and being overtaken
by a lorry!

Watford Gap and powered by the old 100E Ford side valve engine with 3
speed gearbox.


--
Tim Lamb

In article ,
polygonum wrote:
Really cruise control is best served with an automatic box

Actually, I found that with the Saab, it worked pretty well (was
manual), but that was because fifth was so capable. I can't help but
think that the optimum combination would be a CVT with CC. (Shame so few
CVTs seem to be much good other than in 'shoppers'.)

The beauty with an auto is you can up the gearing to the point where the
MPG is best - and not have to continually change down on hills.

I don't like CVTs. ;-) Modern multi-speed autos are more efficient - with
better reliability.

--
*Acupuncture is a jab well done*

Dave Plowman London SW
To e-mail, change noise into sound.

In article , Tim Lamb
wrote:
In message , polygonum
writes
On 18/03/2013 10:47, Dave Plowman (News) wrote:
In article , polygonum
wrote:
Used to have a Saab turbo 16V - that would do almost all motorway
work in fifth, up hill and down dale, without any noticeable slowing
down. CC really highlighted how other vehicles changed speed a lot. I
guess some of that was drivers not using/having CC, and some simply
car engines not able to make it up hills so apparently effortlessly.

If it will climb any hill in top gear, the gearing's too low for best
MPG.

I can't think of a motorway hill it couldn't manage. It was the turbo
that made a huge difference. Of course, on lesser roads, I needed to
drop from fifth.

I had the ultimate embarrassment: driving a Morgan and being overtaken
by a lorry!

Watford Gap and powered by the old 100E Ford side valve engine with 3
speed gearbox.

I upset a Morgan driver by overtaking him in my Anglia estate going up
Stokenchurch hill on the A40 (c 1970)

--
From KT24

Using a RISC OS computer running v5.18

In message , charles
writes
I can't think of a motorway hill it couldn't manage. It was the turbo
that made a huge difference. Of course, on lesser roads, I needed to
drop from fifth.

I had the ultimate embarrassment: driving a Morgan and being overtaken
by a lorry!

Watford Gap and powered by the old 100E Ford side valve engine with 3
speed gearbox.

I upset a Morgan driver by overtaking him in my Anglia estate going up
Stokenchurch hill on the A40 (c 1970)

That 3 speed gearbox was corner cutting of the worst sort. I suppose it
made for a cheap car: sheep in wolf's clothing:-)

I put a 122E (Gt) engine in when the piston slap got too annoying. The
mistake was to use the common 4 speed gearbox which had a very low
second gear.

Sold to finance a house move, the car still exists. How much remains of
what started out in 1956 is unknown but I changed the engine/gearbox,
front brakes, wheels and the ladder chassis. My insurers seemed
unpeturbed at the time but I suspect vehicle legislation has moved on..


--
Tim Lamb

In article ,
Tim Lamb wrote:
Sold to finance a house move, the car still exists. How much remains of
what started out in 1956 is unknown but I changed the engine/gearbox,
front brakes, wheels and the ladder chassis. My insurers seemed
unpeturbed at the time but I suspect vehicle legislation has moved on..

The chassis tends to be the key one. If not a genuine new spare and you
inform the DVLA, you'll likely end up with a 'Q' registration. If
secondhand, you will be given the donor car number.

The SD1 world has lots of this - a 'desirable' but rotten version being
re-shelled with one from a good condition lesser model. And then claiming
to be the 'desirable' one.

--
*The last thing I want to do is hurt you. But it's still on my list.

Dave Plowman London SW
To e-mail, change noise into sound.

In message , "Dave Plowman (News)"
writes
In article ,
Tim Lamb wrote:
Sold to finance a house move, the car still exists. How much remains of
what started out in 1956 is unknown but I changed the engine/gearbox,
front brakes, wheels and the ladder chassis. My insurers seemed
unpeturbed at the time but I suspect vehicle legislation has moved on..

The chassis tends to be the key one. If not a genuine new spare and you
inform the DVLA, you'll likely end up with a 'Q' registration. If
secondhand, you will be given the donor car number.

Morgans had stopped supplying replacement chassis the year before I
needed one (1971). Modern search engines might today have found one
somewhere but the solution at the time was to make one:-)

Again, finding a workshop with the capacity to fold steel sheet to the
length required would be easy today. In the event the *Z* section was
made up in two lengths, assembled to a chalk mark on my garage floor and
welded together by the local blacksmith:-)

The SD1 world has lots of this - a 'desirable' but rotten version being
re-shelled with one from a good condition lesser model. And then claiming
to be the 'desirable' one.

I didn't see a need to tell anyone other than my insurers:-)


--
Tim Lamb