This involved masses of tedious measurements with a microscope on track trajectories, of which the momentum measure was embedded in the average of the modulus of the second difference, a tedious and trivial calculation. It occurred to me that we had the means to hand with which it could be automated, and this we had some fun doing.

I subsequently described the work in a paper in Electronic Engineering (June 1963); the lag was due to my being with Guinness, and it sort of slipped in my priorities.

The abstract was as follows: 'a case is made for the development of a small special-purpose computer for processing of low-grade numerical information which occurs in quantities too small to justify computer processing on the usual scale. A machine is described which used Dekatron tubes and uniselector relays to compute the cumulative total of the moduli of second differences of a sequence of two-digit numbers, at a rate limited by the manual input rate (about one number per second)'.

The dekatron tube was used for storage and for display of the results; it as basically an obsolescent technology, earlier used for counting pulses from radioactive sources, but some work had earlier been done in Harwell by Barnes et al (Electronic Engineering 23, p286, 1951) on the use of the Dekatron in computing and we adapted the concept. We did this as an alternative to using the then available computer capacity (a Hollerith HEC located in the Sugar Co in Tuam) because in the latter case the amount of work needed for data preparation of the input would have been comparable to the amount of work involved in doing the calculation itself. We had in fact used the Tuam HEC for least-squares curve-fitting, in another context.

"Typically... one had to deal with about 100 small numbers per measurement, and possibly of the order of 100,000 to 1M numbers in a complete experiment. In attempting to handle this type of information with existing commercially available equipment, difficulties ere encountered... use of an conventional adding machine is little faster than performing the arithmetic mentally. This holds also for commercial electromechanical differencing engines of the Babbage type. These were better adapted for processing multi-digit numbers where speed is not important... in order to achieve an appreciable improvement over mental arithmetic one requires a machine capable of working ... as fast as two-digit numbers can be tapped into a keyboard..."

In the paper I went into the overall ergonomics of various alternative data capture systems, showing that from the angle of matching output rates of the measurement system to the computer input rate, this made sense.

This was in effect my introduction to some basic techno-economic concepts relating production rates to information processing, and the experience was subsequently useful in industry. There was also a human dimension, in that the observers needed to keep some degree of hands-on control over the quality of the analysis of 'their' particle tracks. If the computation had been banished to a remote processor this would have been lost.

The machine worked for the duration of one experiment, in which we attempted to relate ionisation measurements to momentum on what as known as the 'relativistic rise' side of minimum ionisation. We had already pinned down with some precision the shape of the curve on the low-energy side of the minimum, and we were pushing the technology of nuclear emulsions to the limit.

In the event however the attention of the ionographic emulsion people moved in the direction of the cosmic ray 'heavy primaries' (where O'Ceallaigh and his DIAS group concentrated their attention after I left), and the attention of the high-energy charged particle people (in CERN, Berkeley and the major world centres) became increasingly directed towards the possibilities of bubble-chambers in magnetic fields, and our work turned out to be a blind alley. But it was a useful learning experience, and I regard it positively.

The photomultiplier output signal was a linear measure of the concentration of yeast in beer, and it did not matter if the beer was dark. The then current nephelometry instruments of course were quite useless in Guinness for that reason, and anyway they had a non-linear output. It was a good instrument, with many possible applications, and was subsequently made commercially under licence by Evans Electroselenium. If it had been used outside brewing (eg in paper pulp) I understand I should have been entitled to a royalty, but I never pursued this.

I wrote this up in Research and Development for Industry, no 31, March 1964, giving examples of how it had been applied in the control of the Guinness pilot-scale continuous fermenters.

The second patent 986,343 was headed Controlling Yeast Fermentation and was in effect an attempt by Guinness to evade infringing the then current patents of, if I remember correctly, Coutts and Lebatt. The novelty was in splitting the feedstock between a yeast growth vessel and one or more main fermenter vessels. The yeast concentration in the main fermenters was maintained high by a system for restricting the amount washed out, the yeast being flocculent, and wanting to settle, but being prevented from doing so by a stirrer. The outlet however was via a settling-tube of which the setting could be varied; this shielded the outgoing liquid from the action of the stirrer, thus holding back the flocculent yeast.

The main fermenter got a portion of the feedstock directly, the other portion feeding the vessel where yeast was grown, under aerobic conditions. The output of this growth vessel was fed into the main fermenter, replenishing the yeast supply therein, at a controlled rate.

We developed instrumentation to measure the oxygen level in the growth vessel, and to measure the gravity in the fermenters, and to keep track of the amount of yeast that came out. The rule was, everything must go downstream; no recycling of yeast. This latter feature dominated the Coutts-Lebatt patents, but Guinness wanted to maintain their own system distinct from this, the key idea being to start with pure yeast culture under laboratory control, and not allow a population of wild or mutant yeasts to build up, as would happen under a recycling regime.

We did the best we could, but the system was wildly unstable, and would have required a sophisticated feed-forward control system, based on totally reliable instrumentation. There is a non-linear relationship between the gravity of the fermenting beer and the extent to which the yeast flocculates. The attempt to control yeast concentration in such a way as to achieve the target beer gravity at the outlet, while staying within the 'no recycling' constraint, was doomed to failure.

In the end Guinness went back to the classical batch process, which is self-stabilising and easily manageable. Again, the experience was interesting and useful; one can learn from failures perhaps more than if one has one's head swelled by successes. Above all, we had fun doing the work, and there was a great sense of team cohesion.

I should add that we attempted to develop an on-line gravity-meter, in association with Solartron-Schlumberger (currently a world-leading oil-well instrumentation specialist), which depended on the vibration frequency of a metal tube being modified by the specific gravity of the liquid in it. I don't think this led to a working prototype, but we had observed and measured the gravity effect in another Solartron instrument which depended on vibrations, designed to measure viscosity.

The third patent, 1,004,693, headed Continuous Production of Alcoholic Beverages, was a product of some laboratory prototyping; it never scaled up. (the work mentioned above I should say was on a large pilot scale, of the order of 100 barrels per day). The novelty was to ferment wort to beer by trickling it down a column containing concentrated yeast, in the form of a carbon dioxide foam, the yeast being in the walls of the bubbles. The foam was generated by compressing the liquid and releasing the pressure through an orifice, much as the foam on the pint is generated to this day.

We got this to work, after a fashion, on the bench, but scale-up problems would have been horrendous, and it remains a curiosity. The patent agent however was very taken by it, and had great hopes, and Michael Ashe was persuaded to go through with the patenting.

I seem to recollect recently some similar process being reported in the New Scientist, and Denis Weaire in TCD has recently (ca 2000) done some basic work on bubbles, so if anyone reinvents it, I can claim 'prior art'!

We were able to model the performance of the 3-vessel continuous fermentation system using a set of differential equations, and at one stage we had this working on an analogue computer. I drafted a paper on this, and showed it to Sir Cyril Hinshelwood, who was then consulting with Guinness, and he thought it should be published, but I never got round to it. The key concept was in the separation of the aerobic growth from the anaerobic fermentation phases; these processes obeyed different dynamic laws. It was I think a fairly early example of a mathematical application in biodynamics.

[If I find the paper it is perhaps worth appending in full.]

We introduced an algorithm for loading the cost of the peak service with the cost of off-peak idle capacity, and we also introduced the concept of 'load-factor of marginal seats' which was related to the mean load factor by a power-law. The power selected was different, depending on whether you used larger aircraft or ran a higher frequency; in the latter case the load factor of marginal seats was closer to the average.

The classification of the variables is of interest: we distinguished independent variables requiring strategic decisions (eg aircraft purchase) from those requiring tactical decisions (fly this route at that time) and recognised 'technical constraints' (time to fly a route with a specific type of aircraft). We identified as 'environmental variables' the exponents in the marginal load-factor functions. A key intermediate variable was a 3-dimensional array of partial derivatives of T(j,k) with regard to f(i,j) where the first is the number of revenue passengers in period j in direction k, and the second is the frequency of aircraft type i in period j. We also had as technical constraints the maximum hours an aircraft could fly in a single period, and the annual allowed maximum hours. There was in any period a threshold frequency above which utilisation became period-limited rather than annual-limited. The model was thus full of discontinuities and non-linearities, and its behaviour was complex and 'interesting'.

We went on to apply this approach to the route system as a whole, after testing it successfully on the London route, and we went on the try to develop a rationale for spreading the company overheads over the various routes equitably, in a programme to estimate route profitability in a total company model. The key concept here was the introduction of 'volume-dependent' and 'variability-dependent' components for the company overheads, the first being related to routine operational costs and the second being related to the marketing, planning and scheduling functions. This was, in effect, an attempt to bring 'entropy' into the cost aspect of a company model, and I think it would have been a global first, but I don't know. We did not get as far as doing this 'for real', though we did develop a substantial body of fleet, route and operational software, in Fortran, which I believe ran successfully for some time after I left in 1970.

There are two distinct and largely unrelated fields of work in which the computer has proved to be useful. These may be defined as the 'commercial' and the 'scientific'

The commercial field seems to me to possess in most cases the following features:

(a) handling large volumes of data on a routine basis;
(b) restriction of the analytical capability of the computer itself to a few elementary operations;
(c) domination of the computer management by people who tend to be technique-oriented;
(d) preoccupation of the technicians with micro-problems;
(e) a tendency for programmes once written to be inflexible and difficult to adapt to take advantage of opportunities not seen at specification-time.

The scientific field, which developed earlier, has remained in a world of its own; sophisticated numerical analytical techniques for solving difficult problems at the frontiers of knowledge have occupied the minds of the vanguard. Bread and butter is earned by engineering calculations: stress analysis, aerodynamics etc.

Commercial computer installations tend to be restricted by their place in the organisation to remain at the clerical rather than the analytical level. Installations connected with firms where technology is important tend to be under the engineers, and to be staffed by people for whom the solving of the stress equations is the main object in life.

There is fruitful work to be done in the bridging of these two worlds. This does not occur automatically. I have personal experience of one UK manufacturer of sophisticated hardware who was trying to sell it to Irish users, failing to make the sale. It turned out that his computer was under the control of the engineers, but that his sales department were doing longhand calculations to estimate how the hardware would work out in the prospective.Irish customer system.

It happened that the Irish firm possessed a micro-economic model of its production system, which had been developed for the purpose of choosing between the firms which sold hardware. On the basis of this model, the Irish firm bought hardware from a US competitor.

This story has in fact occurred twice in my experience, the second case being a matter of choice between two US firms.

(The hardware was aircraft, and the firm was Aer Lingus. RJ April 2001)

The moral of this story is that there is scope for the development of micro-economic models to check out if the capital it is proposed to invest in the new hardware will in fact pay off.

The Irish computer scene lends itself particularly well to the development of this type of computer application. Our universities produce many good analytical minds, who aspire to be among the world innovators. Often they look to the technologies of the large nations for their fulfilment, They have not yet realised that our future, as a nation with know-how and expertise, is to jump in and excel where the giants are blind.

Our economic life is not dominated by sophisticated hardware-producers in competition with each other. We can therefore apply our expertise to choosing between the produce of the giant competitors, as it can be used in economic applications in Ireland, or in any other small or medium economy.

In other words, we can set our minds to contracting to build models of economic systems to run on computers, use them to choose what hardware we buy in our own applications, and we can export this as a service to those who need it.

This type of computing is neither commercial data-processing nor is it in the tradition of scientific computing. Nor is it simply a mixture. It is best described as a bridge. It takes the technical coefficients from one side and the unit costs from the other and blends them into a model of an economic system interacting with an environment, subject to technical, marketing, policy etc constraints.

The type of mathematics used comes easily to the computer man who has grown up on the scientific side. There is more to it than mathematics: one needs a sense of scientific analysis when it comes to organising and clarifying the data. It is here that the would-be model-builder runs into the morass of the commercial data-processing world.

It is rare to find a commercial system that abstracts and classifies in such a way as to provide good inputs for an economic model. It will count nuts and bolts, and keep track of the money, but it seems rarely to occur to a commercial system analyst that there might be an interest in classifying costs on the basis of their dependence on capacity, or load, or event-counts, or any appropriate easily measurable statistic. Thus the planning model-builder often has to rely on manual input.

This, while being a weakness in that it makes it hard to link a planning model on to a data-processing system in a large organisation, is a strength in that it means that the model must be economically constructed with much thought put into selecting the really significant features. Micro-economic model building is therefore a mobile, portable, exportable asset.

Nor does a micro-economic model necessarily involve a large computer. The easiest way for this type of know-how to spread is to have cheap hardware readily available, without the need to queue for service. The model referred to above which caused concern to the UK manufacturer was developed on a small machine now regarded an obsolete and unsaleable by the computer manufacturers. Yet it is still perfectly serviceable. Such machines could be used to generalise the knowledge of how to solve problems on computers; it would be quite possible for the State to buy up all the 'obsolete' equipment for a song, organise a group to maintain it, and make computing services available cheaply to every town, technical college, vocational school, secondary school, firm and farm in the country, This, rather than some centralised super-machine, for which 100% utilisation is the dominant goal, is the way forward.