I’ve written about many weird and wonderful inventions on here but I think this apparently madcap contraption might  take some beating!  It all started when I stumbled across an unusual engraving  in the Wellcome Collection. There was no background information, no context, and very little referencing other than the date of publication, 1755.

A bit of dogged hunting through the back streets and byways of the internet led me to an obscure publication and a short article that accompanied the print in its original incarnation there.

At first glance this detail  showing a well-dressed couple looking at some plants   might appear  fairly ordinary but when you look more closely at the rest of the engraving things just get stranger…beginning  with its title…

From the General Magazine, July 1755

No you’re not mistaken – the title really is “A MACHINE for a Perpetual Electrified GARDEN”

So now take a close look at the rest of the print  and see if you can work out what’s going on before reading any further!

I thought at first it must be a satirical comment on some long forgotten event, rather like some  Rowlandson or Cruikshank cartoons but I eventually discovered it isn’t that at all but a serious scientific proposal.  Unfortunately  neither the Wellcome Foundation or Science Museum which have copies of the engraving in their on-line collections had any further information but I eventually tracked down its first appearance to the July 1755 issue of  The General Magazine of Arts and Sciences, Philosophical, Philological, Mathematical, and Mechanical edited and published by Benjamin Martin.

Benjamin Martin 1705-1782

Martin was an interesting character. He was self-educated, became a teacher, wrote a large dictionary that predates Johnson’s more famous one, and later travelled the country giving lectures on natural philosophy.  He also made scientific instruments and had, surprise surprise, written An essay on electricity … being an enquiry into the nature, cause and properties thereof etc etc in 1746.  

The print was accompanied by a short article which  I’m going to quote from to see if I can explain what is supposed to be going on, without being too technical [apologies to anyone with a knowledge of physics, mechanics, hydraulics or electricity for any errors, I failed ‘O’ physics in 1966 and my scientific knowledge probably hasn’t improved much since.]

“As it is our profess’d Design to improve every Discovery for the Public Good, as far as we are able; and as Electricity is now well known to be somewhat more than a Matter of mere Curiosity….

Title page of William Gilbert’s ‘De Magnete’

So what’s all that about?  How could electricity be a mere curiosity when the 18thc didn’t have it?  It’s true they didn’t  in the sense that we normally use today but they did know about static.  As a child I remember discovering   that  rubbing a comb against my sleeve somehow magically allowed it to pick up tiny scraps of paper.   Of course that phenomenon had been known since antiquity although with references to rubbing pieces of amber rather a cheap plastic comb.  But Martin is right that after that static electricity  remained no more than an intellectual curiosity  until 1600 when  William Gilbert published De Magnete , a careful study of electricity and magnetism.

Gilbert  Latinised the Greek word for amber – elektron – as  electricus, and it quickly entered the vocabulary of those interested in natural philosophy and early science.  “Electric”  “Electrical” and “electricity” soon followed.

… inasmuch as it has been successfully applied to the Cure of several Disorders of the rheumatic and paralytic Kind, and to remove Obstructions and Pains occasioned thereby.

The Black Torpedo Fish from “anatomical observations on the Torpedo” by John Hunter 1773

It might appear a big step from the “discovery” of  static electricity to Martin’s claim that  it had been  successfully used to deal with pain.  But in fact it’s not because  since Roman times at least  physicians, including the father of modern medicine Galen,  claimed that the shock patients would get from  a live  torpedo fish could relieve gout and other pain.

(For more on this see  The Torpedo Effect in Medicine by Gregory Tsoucalas et al in International Maritime Health, 2014 and  “A Tale of Two Fishes : Magical Objects in Natural History fro Antiquity through the Scientific Revolution”,  by Brian Copenhaver in Journal of the History of Ideas, 1991 )

Apart from wondering how on earth  they discovered that,  how, apart from catching a lot of torpedo fish, could  enough  electricity be generated to  help patients with rheumatic pain or paralysis as Martin suggested it was?  Well it’s simple…. the amber or my comb produced static electricity by friction, so the first thing  you need to create a lot of static electricity  is a lot of friction.

Hawksbee’s generator from his Physico-mechanical experiments on various subjects, 1709

Just over 300 years  before I  failed ‘O’ level Physics,  Otto von Guericke, invented a primitive form of friction-making machine and it was followed by other more sophisticated devices,  notably   Francis Hauksbee’s  basic generator which involved a glass sphere that could be  rotated rapidly against a woollen cloth to create friction and thus static electricity.  But being able to create static electricity doesn’t actually get the resultant spark to the patient.

That required a conductor and after various attempts in 1744  William Watson, a member of the Royal Society,   invented a more advanced generator that had several glass globes and used a sword and a gun barrel as its conductors. His electrical experiments  were written up in the Transactions of the Royal Society and many of them also in The Gentleman’s Magazine in 1745. ie about 10 years before Martin’s engraving.

All that created “instant” static electricity but  for there to be “Perpetual Electrification” for Martin’s garden machine there had to be a way of storing it.   There was no means of  that energy until in 1746 Pieter van Musschenbroek of Leiden University and his assistant  Andreas Cunaeus invented the Leyden Jar…  a basic form of condenser or capacitor – it was a shocking experience!

Artists impression of what happened in 1746 when Cunaeus  attempted to “condense” electricity in a glass of water. When Cunaeus reached up to pull the wire out of the water, he got a severe shock, much worse than any previous generator could give. He took two days to recover.  Then Musschenbroek himself tried and wrote: “I would not take a second shock for the crown of France”.

All these experiments and successes meant that  by the mid-century  basic knowledge of static electricity had become a fashionable subject for public discussion and debate. Since static  was  easy to generate and could produce seemingly inexplicable impressive effects it led to itinerant lecturers touring the country  demonstrating the mysterious force, as well as mountebanks doing party tricks, such as  making people’s hair stand up or using the electrical spark to ignite a glass of spirits. At the same time doctors  were making serious attempts to utilise electric charges  as therapy for paralysis and indeed other health problems.

One of Wesley’s portable electrical machines.

The preacher John Wesley, for example, also acted as a healer and included electric treatments in his portfolio of remedies. He published a cheap self diagnosis  guide Primitive Physick which by 1760 included using electricity for helping cure deafness, ear-ache and toothache,  while it’s known the dispensaries he was involved with running were offering electric therapies  from 1756. One of his patients, John Read, was a cabinet maker who made a cheap portable generator that  became a standard instrument and especially practical for medical purposes.

For more on this see Paola Bertucci, Revealing sparks: John Wesley and the religious utility of electrical healing,

But Benjamin Martin was promoting electricity being able to do as far more than that.  It was he wrote: ” well known greatly to promote Vegetation in Plants…”   

Demainbray

Have you ever heard of anything so bizarre as electrifying plants to make them grow?  Yet it was widely accepted at the time. I found contemporary accounts saying that a Scot named only  as “Dr. Maimbray”  carried out experiments to do just that in 1746.  Again very little context or further information was ever given to these accounts so I started researching in continental sources and discovered that the man concerned was actually the son of French Huguenot refugees and born in London in 1710. His name was Stephen Charles Triboudet Demainbray, who had studied at Leiden and then  ran a school in Edinburgh for young ladies.  But he had a sideline in electricity.

By 1747 he had experimented on the effect of electricity on plant growth and published a short letter on the subject in the Caledonian Mercury.

from the Caledonian Mercury 20th Feb 1747    [apologies for the poor quality of the image]

Although he did not pursue this work further,  others did. The Royal Society heard a paper which described the the experiments of a Mr Baker who electrified a myrtle at the Duke of Montague’s, at Ditton but their observations were  “confined to the divergence of the electrified leaves, and the beautiful appearance of the aura proceeding from the points of the leaves when seen in the dark”.   Other gentleman scientists across Europe picked up on these reports and repeated and extended the experiments.

Later Demainbray too became one of those fashionable  travelling lecturers. Luckily for him some of his lectures were heard by the future George III and eventually in 1768 he was appointed superintendent of the king’s new astronomical observatory at Kew. Many of his machines and instruments  [but nothing electrical] are now in the Science Museum and can be seen in this Youtube clip.

from Abbe Nollet’s Recherches Sur Les Causes Particulieres Des Phénoménes Électriques. 1749

Nollet’s “electric boy” experiment has a boy hanging from insulating silk ropes and given an electric charge.  A woman is encouraged to bend forward and poke the boy’s nose, to get an electric shock herself.

The scene now shifts to Europe  where Abbe Jean-Antoine Nollet picked up on Demainbray’s experiments and tried some of his own. He was also a showman who made a fortune out of the electrical divertissements he devised for the French aristocracy, most famously the electric boy.  Nollet also experimented  with a whole range of techniques on a wide range of living things including seeds and plants which reported to the French Academy of Sciences in 1748. and which he wrote up in several books.    Germination of seeds was several days quicker but the resultant plants  weaker.

Meanwhile Professor Jean Jallabert  in Geneva repeated those experiments and also tried growing hyacinth and narcissus bulbs within an electric field. They grew faster and bloomed quicker.   A whole host of other scientists were soon doing similar things. These and the experiments carried out by others were well reported in both the British and European magazines and academic societies’ transactions and then included by Joseph Priestly in his History of Electricity of 1768.  Even the Royal Society agreed the case for electricity improving plant growth was proved  in its Transactions of 1777.

Now Martin went one stage further. In order to create a perpetual Electrification of animal and vegetable Bodies…  we here propose a MACHINE, which we think will be sufficient for an Experiment of this Kind. It is the Application of the Hydraulic Machine invented many years ago by Dr Barker; with a proper Apparatus for perpetually Electrifying the Plants and Fruit Trees of an artificial Garden.

Dr Barker’s Mill from “The Cyclopædia” of Abraham Rees, 1820

Many references to Dr Barker and his device,  sometimes known as Barker’s Mill because it was later adapted to grind corn, suggest it is a 17thc invention. Although this might be possible – indeed Martin suggests it was invented “many year ago”-  it’s more likely to have been devised or certainly substantially improved by Robert Barker a member of the Royal Society in 1743.

It’s  powered by water which flows into a rotating vertical tube and is then  discharged through nozzles at the end of two horizontal arms at the base in a similar way to a  a modern rotary lawn sprinkler.  The power generated is taken off by a belt around the tube.

Here’s a detail of the print showing Martin’s machine…

In the centre you can see the “upright tube or Body of the Machine, 8, 10 or 12 feet in height”,  and at its base “the horizontal Trunk thro’ which the Water spouts from Holes at each End, but on contrary Sides.”  At the top are two glass globes which are “turned by the machine by means of a cord” and so rub against two cushions “pressed in place.. for greater or lesser Degrees of friction.” Projecting out from the frame are two iron rods, suspended on silk ropes,  which act as the conductors to the wooden frame on which the garden sits.  Notice that the legs of the frame sit on blocks made of resin or wax which act as insulators.

Martin suggests “in this garden may be placed in Pots any sorts of Plants, Flowers etc, which when the machine is in motion maybe constantly electrify’d. One Globe is enough to be in Motion at a Time; and when that is too hot, the other maybe put into Motion: and so they may be alternatively used Night and Dy without Cessation of the Electrical Effluvia on the Plants.”

Did Martin actually make a prototype? I suspect not  because he finishes his article by saying “As a constant Stream of Water may in most Places be had and as the Expence of such a Machine and Garden would not be very great, it is much to be wish’d. that those who have it easily in their Power, would oblige Mankind with some attempt of this Nature that they might be satisfied what could be effected in Medicine or Physics, by a perpetual Electrification.”  He obviously thought the idea would appeal to the sort of wealthy clientele seen in the engraving in their beautiful greenhouse.

So I thought that’s just  another madcap idea that disappeared without trace but once again I was wrong as I’ll show in another post soon….