Fred Hoyle: An Online Exhibition
A Letter to his Father
Aug 17th 
I got your letter yesterday morning. If it had come any later I should not have been able to have got the telescope. When I went the assistant showed be [sic] the thing & I asked about the lenses. The object glass is achromatic i.e. it consists of two or three separate lenses. This particular one has three lenses. Achromatic object glasses are the best. The astronomical eyepiece has a power of x80 (magnifies 80 times). This is neither too powerfull [sic] nor too weak for a telescope of its size. The terrestrial eyepiece varies from x40 to x80. In addition there was a tinted glass for solar observations & a teak case with dove-tail joints.
The assistant at my request measured the diameter of the object glass. It was not 2 1/2" but 2 3/4". This would increase the power by 1/3 of what I expected it to be. This seemed to me to be too good a bargain so I asked the man to let me test it & bring it back if I was not satisfied. The case with the thing in must weigh about 2 stones so it was no easy matter getting it back to Dartford. We unpacked it and set it up, with the terrestrial eyepiece in & pointed it at a tree about a mile away. We had to have the eyepiece pulled right out to focus it (at its lowest power). The tree looked about a yard away. I say the tree but a small branch filled the field of view. The telescope is fine for observing birds. Using the astronomical eyepiece & tinted glass & after a bit of trouble I focused it on the sun. The sun looks like a bit of blue sky. You could see the solar disk or rather part of it for one limb filled the field of view. It was not actually a bit of blue sky because if you pointed the telescope elsewhere the field vanished & all was black. So much for the sun. I thought once & for all I would see what that mysterious star in the southern sky was. The one that baffled all of us. We thought it was either Mars, Saturn or Fomalhaut. I knew it wasn’t Fomalhaut because of the star charts in the Dartford Library. I favoured Saturn. It was Saturn. When we got the telescope focused we could see a white ball then a black ring & then a bright one. Like this: [diagram of Saturn]. We had seen the rings of Saturn. It was a beautiful sight.
I tried zeta in the great bear. This star is called Mizar & is the one the 29/- telescope before the war was guaranteed to split. Mine split it so easily that one half looked about as bright as Sirius or brighter like Venus & was at one side of the field & the other half about as bright at the other side of the field. My telescope should split stars of the 6th magn. 2” apart. The stars in Mizar are 2nd magn. & 14” apart. I tried Arcturus. It was wonderful to see the star changing colours. Mother talks about sirius being like a ball of white-hot electric wires, but she must have had the telescope out of focus for when in focus the star appears like a point of light. I just glimpsed the moon and the result of this was rather disappointing as I hadn’t my telescope focused properly & so could [not] get a proper view. I hadn’t time to focus it as Mr & Mrs Wood were going to bed.
P.S. Hope you cook your own meals well (Ha-Ha-Ha)
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