A.M. Instruments, Rover 20

[SHyslop]

Looking at my 1938 20's instruments yesterday, I was reminded that the speedometer and clock weren't labelled Jaeger as might have been thought on a casual glance. The speedometer is labelled "A.M. Instruments London" . I have been examining the pictures of another 20, ELD428, when it was for sale, and it has the same speedometer too.
I am suspecting that these are actually a Smiths/Jaeger production, but maybe not? I can't say in 40 years of older vehicles I've come across anything else made with this name on it which makes me think they would be a confection to help justify the price of the 20 , but I'd be happy to be proved wrong. Does anyone know definitely ? I've no desperate reason to take anything on the dashboard apart just out of curiosity although an examination of the workings would probably betray their origins. Thanks very much for any information.

[David2021]

I know that Smiths made 8 day clocks for aircraft during the war. I remember seeing one apparently for a Spitfire advertised at something over £1000 and it was marked A M on the back with a Kings Crown. I imagined that A M stood for Air Ministry? It did not have the Ordnance Broad Arrow mark such as was (is) always on eg military watches.
This probably doesn't help you in your search for A M Instruments London, but perhaps Smiths were making clocks for the Ministry at that time? Would people have been aware of A M significance and been impressed?

[SHyslop]

Dear David,
Thank you for taking the trouble to think about this question. I have to own up to having made a mistake. I had not remembered correctly that the designation on the speedometer was "A.T." and not AM. The fault is mine, the photo I had of the other car was slightly indistinct but looking more closely I see it too is A.T. The full inscription on the front is "A.T. Speedometer Co. London NW2". I have looked through the Smiths/Jaeger histories but so far haven't seen anything that on paper would link them to "A.T."

However, I did look out an aircraft clock I have and it does show AM on the back, albeit without the crown. I really appreciate you thinking about this question and coming up with a good idea. It has made me look out that clock and think about it and the search for A.T. continues. I have tried to insert some photos but they need resizing and the computer I have is really not up to the job nowadays. Thank you once again.

[David2021]

This is a real rabbit hole to dive down!
I have found Smiths MA (with a very stylised MA) fitted to many late 30's motorbikes; and Smiths Chronometric speedos with plain capital M A on them! They all will have unique numeric part nos on the face and and indication (4 digit) of the number of turns . Look at https://www.classicbikepartscheshire.co ... tachometer if you REALLY want to get confused!
Maybe MA was to indicate that the speedo was "MAgnetic?" Someone may know!
What I thought was amazing was the price of these repro speedos! Probably originating from India! How they work or how they are calibrated goodness only knows....
I have almost certainly got an incorrect (Jaeger) speedo on my post war 12 tourer, but have not been able to find what I think is a right 'un! Mine is not the same number as Luli's certainly! there was a bit of a thread on it a while back.
David

[SHyslop]

Great ! Yes, these copies are usually from India. I've had some Indian made 2" gauges for various things and they've proved excellent, all working and each under £30. You're right, Smiths did indeed have "MA" as part of their logo and I think it was for "Motor Accessories" but in addition, they gave a letter designation to a lot of their 1930s speedometers, the PA of early 30s Austin 7s being a common one. I have had a little help with photo sizing and so I hope to include the photos I had intended loading before, being the "AM" on the back of the aeroplane clock and the 20 speedometer face.

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[HAD501]

I worked at Smiths Industries (Aviation Division) for many years, so have some interest in the history of the company. There is a brief reference to A T Speedometers Ltd in James Nye’s history A Long Time in Making - The History of Smiths. Looking for more detail I tried some googling and came up with this:

https://velobanjogent.blogspot.com/sear ... eedometers

The AT instuments appear to be better quality than the British Jaeger which I'm sure are just badge-engineered version of the standard Smiths offerings.

DaveM

[SHyslop]

Dear Dave,
Thank you for looking out this information, it is most interesting and I am very grateful for having a gap in my knowledge filled. I used to have a 20/25 Rolls and I did wonder where it would be that their speedometers came from and now I know. I hadn't appreciated that there was a third division to Smiths but, looking at A.T.'s catalogue is exceptionally illuminating. Going by the price of £7 for a speedometer, they were producing items of considerable expense. The location of 0 on the face is virtually the same as on the Jaeger chronometric speedometers used from 1932-36 on Daimlers and Lanchesters, of which I've had several apart and fixed (similar ones on lots of British bikes), but by the end of that period, the magnetic speedometer seemed to have generally taken over in all the speedometer markets. They were ok when working well but possibly their worst incarnation was on Morrises of the middle thirties with the large square speedometer or some Rootes products with very large oval dials and the needle showing a steady 20 -60 mph as it wavered constantly.

It's always good to meet with or hear from someone who worked for the companies we know of largely from literature of the past. Just as a "by the way", I went to help out a chap some years ago who was restoring a Morris 8. It turned out that he'd worked for the Zenith Carburettor Co. in Honeypot Lane, another of those addresses that stuck in the mind, as did the association of Smiths with Cricklewood originally and then Chronos Works.

[RobHomewood]

What I am wondering is why these spedometers appear to be upside down compared to the one in my 14? Ie the zero on the dial is at the top as well as the 80mph. Is there a logic?

[David2021]

Now we know! What an amazing resource is at our fingertips! You just gave to know where to start! Is it not a reminder about engine speeds on the pre war era that the rev counters in the catalogue only went up to 4000 in most instances

[SHyslop]

Regarding the starting point on the speedometers, maybe a bit of context. My father always talked about the "clocks" on the cars, gauges are on steam engines and a dial is what you do with a phone. A different era. Going back to the clocks, I suppose we've sort of got out of the way in many walks of life of thinking about angles and clock faces but if you think of the enemy being at "5 o'clock" or stopwatches starting at 12 o' clock, plus all angular measurements starting at 12 o' clock, you start to see one part of the thinking for a speedometer starting near the top of the dial. Another phrase was "the full of the clock" which meant going from 12 to 12, not from 7 to 5 !

The second part is that the 90 degrees of a speedometer which is sited closest to the driver's quick flick of the eyes to the instrument, is the most useful. The 20, 30 and 40 mph figures are the ones the driver would and still does wish to have most knowledge of and anything above that is a comparatively rare occasion. Should this seem a slightly unlikely set of affairs for today, it's maybe worth remembering that as late as the MG TC, they were fitted with a 30 mph warning lamp which came on at about 25mph and went off above 35mph to let the driver know they were (about to ) break the speed limit. (The settings could be adjusted as it was connected to the chronometric mechanism).

Combine the two and I think you have a fairly decent rationale for starting with zero at a point near the top and with all the numbers that really matter closest to the driver and at 3,4,5 and 6 o' clock. The problem with starting at 12.00 is that, on quite a few earlier dashboards, the view of the top of the dial may have been slightly obscured because of a top rail below the windscreen and the line of sight from the wheel making the 3.00 to 6.00 view the easiest. Not all by any means but quite a number of the supposedly faster cars of the 20s and 30s had instruments laid out this way. I'm enclosing a couple of pictures of two that just happen to be to hand, on my 1932 Lanchester and 1935 Daimler. However, by the late 30s the magnetic speedometer with a zero in what we'd now think of as the conventional position had largely taken over, probably largely assisted by the move of instruments from the centre of the dashboard to in front of the driver, although Rover resisted this until the P4.

The one thing I really fail to understand today is why, in a country with a maximum speed limit of 70 mph, we allow cars to be sold new with speedometers which go up to 160 or 180. The greater part of the dial is never used and a better laid out dial going up to no more than 100 would be much more use, although fortunately a digital speed read out has helped with that.

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