2°) The Carr House

It is commonly stated that Horrocks made his observation of the transit from Carr House near the village of Hoole in northern England. Nowhere in his account, however, does Horrocks mention Carr House or even Hoole. What is the evidence ?

We do know that in the late 1630s he spent some time in Hoole: Many of his letters give the village as his home. In Venus in Sole Visa, however, all that Horrocks says is that he observed from "an obscure village where I have long been in the habit of observing, about fifteen miles north of Liverpool." It is not unreasonable to assume that this meant Hoole, but what about Carr House?


The Carr House

There is no mention of Carr House in any of the available writings of Jeremiah Horrocks. It is however one of the few contemporary houses which still exists. It was built by the wealthy Stones family and it is entirely possible that Horrocks was a tutor to their children. Certainly there is a long tradition that he observed the transit from a narrow first floor window above the front door. The famous nineteenth painting by Eyre Crowe shows Horrocks observing from this window (with totally unrealistic equipment!). But could the Sun have been seen from this window from sunrise until sunset on 4th December 1639 (new-style calendar): the day of the transit? This was the interesting astronomical question addressed by Sidney Gaythorpe (1880-1964) in a paper submitted to the British Astronomical Association in the 1930s.

One only needs to look at the catalogue of Gaythorpe's archives- now held at the University of Illinois (USA) - to see that he devoted many years of his life in pursuit of the truth about Horrocks. Gaythorpe was meticulous in his research. He visited Carr House and made detailed measurements of the room behind the window. He also obtained exact co-ordinates for its latitude and longitude (53º 41' 11.8" N, 2º 48' 49.2"W). He investigated the type of lenses which might have been used in Horrocks' telescope and deduced the distance which would have been required behind the window to project an image of the Sun as large as that described by Horrocks (150 mm).



Picture of the sun's image recorded by Horrocks – Hevelius Diagram

The outcome of Gaythorpe’s calculations was that, allowing for low hills in the east, the Sun’s azimuth at sunrise would have just enabled it to be seen with the 1.5 inch (40mm) diameter galilean telescope of Horrocks. Furthermore, the last moment at which one could have seen the Sun from this window coincided with the time of Horrocks' last measurement. Perhaps Carr House therefore could have been the site of the momentous observation. It would be nice to think so, because that would give us a visible reminder of the momentous achievement of Jeremiah Horrocks. But ‘perhaps’ is the strongest word we can use. We will maybe never know much about the short life of that youthful genius, but I am sure that many authors will be willing to let their imagination supplement our ignorance. Never believe everything you read!