As for the iodates, new ventures at the Clock House had rendered them definitely passé. There were experiments to measure air resistance, liquid friction, another problem in physical chemistry with Rupert ('I enclose the integral which you might like to try'), plans for a twenty foot long reflecting telescope, and

而钟屋进行的新实验，则使碘酸盐的问题被抛到脑后了。有测量空气压强、液体摩擦力、还有一个和拉普特一起做的物理化学实验，20英尺长的反射望远镜计划，还有……

… So far all I have done is to make an adding machine for pounds and ounces. It works surprisingly well. I think I have given up Maths for these holidays, having just read a very good book on Physics in general including relativity.

我又添了一台新机器，非常好用。假期我没读数学书，只读了一本关于物理、包括相对论的书，那本书很好。

Alan laboriously copied the ingenious experiment on air resistance that Christopher had devised and wrote back with more ideas about chemistry and a mechanics problem, only for Christopher to pour cold water on both in a letter of 3 September: method. Incidentally I believe you're equations of motion have a mistake in them. …

艾伦努力地重复了克里斯朵夫设计的测量空气压强的实验，并在回信里谈了一些关于化学和机械的想法。但是，克里斯朵夫却在9月3日的信给他泼了冷水：

I am now helping my brother analyse American plasticine for an artist. … The procedure is to boil with organic solvents. … I made a quite good plasticine and very nearly like the stuff we want, by mixing this iron soap with flowers of sulphur … and adding a little mutton fat. Hope you are having good holidays; see you on 21st, Yrs, C.C. Morcom.

我没认真研究你的圆锥摆，我没看明白你的方法，但要提醒一下，你里面的运动方程有个错误……我现在在帮我哥哥为一位艺术家分析胶土……用有机溶剂烧……我把硫磺混进铁皂，做了一种还不错的胶土，就跟我们想要的差不多……还加了一点羊脂。祝你有个愉快的假期。21日见。你的C.C.默卡。

But chemistry had now given way to astronomy, to which Christopher had introduced Alan earlier in the year. Alan had been given Eddington's Internal Constitution of the Stars by his mother for his seventeenth birthday, and had also acquired a 11/2-inch telescope. Christopher had a four-inch telescope ('He never tired of talking about his wonderful telescope if he thought one was interested') and had been given a star atlas for his eighteenth birthday. Besides astronomy, Alan was also reading deep into The Nature of the Physical World, for in his letter27 of 20 November 1929 there was a paraphrase of part of its account:

在这一年早些，克里斯朵夫还给艾伦介绍了天文学，现在化学要为天文学让路了。艾伦的母亲，在他17岁生日时，送给他一本爱丁顿的《恒星的内部结构》，还有一个1.5英寸的望远镜。克里斯朵夫有一个4英寸的望远镜（“他一有机会，就会滔滔不绝地讲他绝妙的望远镜”），18岁生日时还得到了一本地图集。除了天文学，艾伦还在更深入地阅读《物理世界的本质》。在1929年11月20日的信中，有一段话：