[ 20 ] measurement of vertical angles. Indeed, in most cases, mere in spection is often sufficient to enable him to hit the angle to the nearest degree. One instance of the perfection he has attained by practice came before w when I ww him for the first time. Some of my friends doubted his pretensione to practical astrononsy, and were desirous of testing his knowledge. One evening when Mars and Venus were about 6° apart in the western sky, he was requested to shew, if he could, with the help of any improvised instrument the actual distance between the planets. After a moment's pause, he made his Mánayantra out of a stick 42 digits long attaching & croespiece of 44 digits to one end. The tri- gonometrical functions of sines and cosines were all committed to his memory. The necessary calculations were mentally maade, and the instrument was ready in a few minutes. On this occasion, he saw a telescope for the first time. He had heard of its wonderful powers, but had no idea of its performances. He requested me to shew him the planets through one. Unfortunately, I had with me theb a telescope no bigger than a refractor of 31" diameter. This was adjusteck for him with a power of 80. The keen delight with which he looked at the varied and picturesque appearance of the moon, absorbing him for some time, car better be imagined than described. When the novelty of the aspect had abated a little, he wanted to know the magnifying power. He was told to find it out for himself, if he could. The question is itself puzzling, and I did not expect any answer. But he startled me by saying that the instrument magnified about one hundred diameters. "
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