OF ARTS AND SCIENCES. 93 



what any one who has only the slightest acquaintance with the 

 appearance of the whole visible spectrum must have noticed — the 

 entirely casual way in which the lines, all along from red to violet, 

 are juxtaposed. There is no more apparent order in their arrange- 

 ment than in that of undergrowth in a primitive forest, or of any 

 other disposition of natural objects which we assign to chance. But, 

 if in walking through such a forest, we came to an open space in 

 which the trees were planted two and two, with the most formal regu- 

 larity, we should hardly doubt that something else than chance had 

 been at work. If we measured the distances and found that these 

 pairs had been set out with such precision that our best instruments 

 could detect no difference between them ; if we further found that 

 the spaces between the pairs were themselves not casual, but ar- 

 ranged with exactness in a certain progression, — if we found all 

 this, we should certainly, in the use of ordinary language, say that 

 here Nature had given place to art. If, further on, we saw a second 

 arrangement like the first, which resembled it closer the more we 

 examined, we should find our conclusion for design, if possible, 

 strengthened. It will be seen, I think, that precisely this abrupt 

 transition from confusion to order and symmetry exists in the spec- 

 trum, as well as in the singular duplication of the design. What might 

 be called the result of intelligence, if observed in another field of 

 Nature, we must here call conclusive evidence of the existence of law. 

 No accident, but some still hidden law, has regulated, I do not doubt, 

 the curious relations now exhibited. Perhaps, with regard to them, 

 we may be standing ourselves in the same position as those few did 

 who were enabled to contemplate the Fraunhofer lines in the first 

 years of their discovery, and recognize that, though we cannot find 

 their meaning, it promises to be worth knowing. 



I had at first meant to present to you some attempts of my own 

 toward a solution. Afterward, considering how little I knew, it 

 seemed to me better to offer nothing in the way of hypothesis now, 

 but for the present to limit myself to furnishing facts, necessary in 

 the creation of any future theory, in the shape of the results of exact 

 measurement. These are given in the accompanying pages, and give 

 sufficiently exact data, I hope, for determining the laws of the numeri- 

 cal harmonies here so plainly latent. 



The best drawings of the A lines I have seen are those recently 

 given by Professor C. Piazzi Smythe, Astronomer Royal for Scot- 

 land. They were obtained in June, 1877, at Lisbon, whither Professor 

 Smythe made a special voyage to obtain a high sun and clear sky. I 



