494 THE POPULAR SCIENCE MONTHLY. 



At the end the day and the month will be again equal, but they will 

 each be 1,400 hours. The moon will then go round the earth in 1,400 

 hours, while the earth will rotate on its axis in the same time. In 

 other words, the day is destined in the very remote future to become 

 as long as fifty-seven of our days. This epoch will assuredly come if 

 the universe lasts long enough. When it has come it will endure for 

 countless ages. It would endure for ever if the earth and the moon 

 could be isolated from all external interference. 



"We heard a great deal a few years ago about the necessity of 

 shortening the hours of labor. I wish to point out that the social re- 

 formers who are striving to shorten the hours of labor are pulling one 

 way, while the moon is pulling the other. The moon is increasing the 

 length of the day. The change will be very gradual, but none the less 

 is it inevitable. Where will the nine-bours' movement be when the 

 day has increased to 1,400 hours ? This will be a very serious matter, 

 and there is only one way by which it can be avoided. The question 

 is one rather for engineers than for astronomers ; but I can not help 

 throwing out a suggestion. My advice is : Anchor the moon, and keep 

 it from going out. If you can do this, and if you can also provide a 

 brake by which the speed of the moon can be controlled, then you 

 will be able for ever to revel in the enjoyment of a twenty-four-hour 

 day. 



Should this engineering feat never be accomplished, then we have 

 only the 1,400-hour day to look forward to. Nor is there anything 

 untoward in the prospect, when we take natural selection, as our com- 

 forter. By natural selection man has become exactly harmonized with 

 his present environment. No doubt natural selection moves at a dig- 

 nified pace, but so in all ti'uth does tidal evolution. Natural selection 

 and tidal evolution have advanced pari px^^su through all the past 

 millions of geological time. They will advance pari passu through all 

 the ages yet to come. As the day lengthens, so will man's nature 

 gradually change too, without any hardship or inconvenience. All 

 that is necessary is plenty of time. Should we think it a hardship 

 that our children should have a day of twenty-four hours and one sec- 

 ond instead of twenty-four hours ? That the day enjoyed by our 

 grandchildren should be a second longer than the day of our children ? 

 That the day of our great-grandchildren should be a second longer 

 still, and so on continually ? This would be no inconvenience what- 

 ever. No one except the astronomers would be able to detect the 

 change, and daily life would be unaltered. Yet, carry on this process 

 for only 150,000,000 years, and we shall find that the whole change of 

 the day from twenty-four hours to 1,400 hours has been accomplished. 

 The actual rate of change is indeed much less than this, and is at pres- 

 ent so small that astronomers can hardly even detect it. 



Our remote posterity will have a night 700 hours long, and when 

 the sun rises in the morning 700 hours more will elapse before he can 



