i66 



SCIENCE. 



bom Observatory — a fine instrument constructed by 

 the celebrated Repsolds, of Hamburg, and which must 

 have few equals in this country. It must be the oc- 

 casion of serious regret that such a splendid piece of 

 mechanism is put only to the task of the mere deter- 

 mination of time, when it is adequate to the deter- 

 mination of the exactest sort of fundamental star- 

 positions. We may be permitted the hope that the 

 creation of a new fund by the citizens of Chicago 

 may ere long contribute to the very possible result of 

 placing the Dearborn Observatory on a permanent 

 footing as one of the first institutions of the kind in 

 this country. 



The Royal Danish Academy of Sciences has re- 

 cently offered a prize of 320 crowns for the best dis- 

 cussion of the theory of the accidental errors of a 

 clock. These errors may be divided into two classes, 

 those arising from errors in the time observations and 

 those depending upon the quality of the clock. These 

 latter in turn may be divided into those depending 

 upon the irregularities of the rate of the clock and 

 those which are independent of the rate. The dis- 

 cussion must include a practical method of determin- 

 ing the value of each of these kinds of probable errors 

 independent of the others. 



AMERICAN ASSOCIATION FOR THE AD- 

 VANCEMENT OF SCIENCE, 1880. 



(Continuation of /a/ers read.) 



ON PATENT LAWS AS A MEANS FOR THE 

 ADVANCEMENT OF SCIENCE. 



By Prof. B. S. Hf.drick, of Washington, D. C. 



The proper aim of science was defined to be the making 

 of discoveries. The discoverer of a new mineral, a new 

 plant, a new law of nature, or a new world, has no proprie- 

 tory right in his discovery. The honor and distinction he 

 obtains is his reward. The discovery, then, cannot be the 

 subject of a patent. The laws of nature, the properties of 

 matter, the physical forces, the laws of their generation 

 and government, are like the earth, the air, the water, the 

 common property of all. Property in the former, as in the 

 latter, is created by enactment. But in civilized communi- 

 ties the reason for the law is that something has been 

 d to what was given by nature. The land has been 

 fenced, ploughed, planted, or buildings placed upon it. 

 Thai gives the Foundation for proprietory right, and public 

 policy requires thai this be recognized, and civil, munici- 

 pal and common Law does this in the case of the land, the air, 

 and the water. The patent ldws do the same when discoveries, 

 the properties of matter, the forces, the laws which govern 

 them, are made to take tin shape of useful inventions. The 



invention which the inventor created is seemed to 

 him as his property for a period at least. Hut 

 note the laws themselves. It is the reflex action of 

 the inventor thai acts to advance science. Illustrations 

 were given by referring to Watts' steam engine in advanc- 

 ing our knowledge of the laws of heat; the telegraph in 

 giving an immense development to the source oi magnet- 

 ism and electricity; and now the telephone and othei kin- 

 dled inventions serve to push our knowledge into the far- 

 thest and outermost borders. The probation given by the 



patent laws enable the great host of investigators to carry 

 on their researches, and instead of becoming a tax or bur- 

 den to the continuity, they help themselves and bear a 

 full share of the ordinary burdens of society. Reference 

 was made to Wheatstone, Bessemer, Perkin, Graibe, Sir 

 William Thompson, and others in Europe, and to Morse, 

 Page, Henry, Gale, Bell, Edison, and many other mem- 

 bers of our association, men who have greatly advanced 

 science, and have received of the rewards which flow from 

 the operation of patent laws. 



THE MEAN RATIO OF OXYGEN TO NITRO- 

 GEN IN THE ATMOSPHERE. 



By Professor E W. Moelf.v. 



In the afternoon Prof. E. W. Morley presented the fol- 

 lowing remarkable conclusions from experiments : When 

 the air at a given place is cold and the barometer high, 

 there may sometimes be a vertical descent of cold air. 

 Samples collected at such times are more likely to 

 approach the composition of the upper atmosphere than 

 those collected at other times. If there be any cause 

 which tends to produce an excess of nitrogen in the upper 

 atmosphere, the average per cent, of oxygen in many samples 

 collected as mentioned, will be lower than that of other 

 samples. Therefore, to determine whether there be any 

 difference in the composition of the lower and upper 

 atmosphere, Professor Morley collected samples of air 

 during each time of unusual cold and high barometer from 

 September, 1878 to April, 1879. In 1878 the average 

 amount of oxygen in these was 0.16 per cent, below that of 

 other samples. In 1879 the average was 0.12 per cent, 

 lower. Careful revision fails to detect any source of error. 

 Professor Morley was led, therefore, to presume that the 

 upper atmosphere, is acted on by a cause tending to re- 

 move part of the oxygen, and to pursue the inquiry by 

 means of a series of daily analyses in duplicate of air for 

 six months, and a comparison of the results of analysis 

 with the thrice daily maps of the United States Signal 

 Service. He finds a deficiency of oxygen at times, and 

 only at the times, when a vertical descent of air at or near 

 the place of collection may be inferred with a fair degree 

 of probability from these maps, and sometimes a deficiency 

 when a vertical descent may be regarded as reasonably 

 certain. 



MAXIMA AND MINIMA TIDE-PREDICTING 

 MACHINE. 



By William Ferrill. 



This machine is merely prospective as yet, and is designed 

 to indicate, by means ot indices on its face, the times and 

 heights of high and low water for any tide station. These 

 have been determined heretofore by means of laborious 

 computations. The mathematical principles upon which 

 the proposed machine is based, and also the internal struc- 

 ture of the machine, are both very complex, and no idea of 

 them can be conveniently given here. The face of the 

 machine is to be 20 inches by 16 inches, and the depth of 

 the case 6 or 8 inches. The face contains an hour circle 10 

 inches in diameter, and a lunar and solar index turning 

 around the same centre with slightly different velocities, the 

 one pointing out the lunar time and the other the solar 

 time elapsed from the time of an assumed epoch, as the 

 first of January. There is also an index moving vertically, 

 indicating the heights of high and low water. The machine 

 is designed to stand upon a desk, and the power is the left 

 hand applied to a crank on the side, leaving the right hand 

 free to record the result as read from the face of the machine. 

 The crank is turned until the lunar index comes in con- 

 junction with the upper or positive end of a needle, also 

 in motion, when the solar index indicates the time of high 

 water and the vertically moving index the height ol high 

 water. The same for low water when the lower index comes 



