October 31, 1884.] 



SCIENCE. 



415 



away with this by publishing their time-tables 

 to twenty-four hours. But the great obstacle 

 lies in the dials of our watches and clocks ; for 

 until the hour-hands are made to revolve once 

 in twenty-four hours, either on a separate dial, 

 like most astronomical clocks, or with a separate 

 twenty-four-hour division, and numbers on the 

 main dial, people will naturally cling to the 

 twelve-hour period. There is also the addi- 

 tional obstacle, that, if clocks are to strike 

 to twenty-four, these large-numbered hours 

 would seem interminably long ; but the change 

 in the striking arrangements would not be of 

 so much importance. 



It seems unfortunate that Mr. Allen's reso- 

 lution for local times, differing by whole hours 

 from the universal time, was not recommended ; 

 for this would seem to be by all odds the sim- 

 plest wa} T of connecting local and universal 

 times. It is alread}^ in almost universal use 

 in this country. 



The sixth resolution of the conference, rec- 

 ommending that the nautical and astronomical 

 days correspond with the civil, is open to dis- 

 cussion. The two naturally go together. And 

 to the navigator it is of little moment : he 

 would simply change his chronometer-reckon- 

 ing twelve hours, buy a new ephemeris, which 

 the astronomer would have computed for him, 

 make the proper entry in the log, and go on as 

 before. With the astronomer it is a more im- 

 portant matter. The ephemerides are issued, 

 and the computations projected, so far ahead, 

 that five years at least would elapse before the 

 change could be made, even if agreed upon 

 to-day. But with the astronomer there is the 

 same reason for changing date at noon as for 

 changing the civil date at midnight. While 

 the rest of the world is sleeping, he is at work. 



The seventh resolution of the conference, 

 which would seem to be a rather poor transla- 

 tion of a French original, contains a sugges- 

 tion as important as any thing it did. We 

 believe that all systems of weighing, measur- 

 ing, dividing, and reckoning any thing what- 

 ever, should be the same as the system of 

 numeration in use ; and, as long as this is so 

 universally decimal, such should be the system 



for all these. No doubt, an octaval system of 

 numeration, with its possible subdivision, 8, 

 4, 2, 1, would have been originally better ; but 

 there is no sufficient reason for a change now. 



NORTH-ATLANTIC CURRENTS. 



From time to time the great iron sea-buoys 

 set to mark shoals, or to indicate entrances to 

 channels, are forced from their moorings, and 

 go adrift. 



These buoys are of several t}^pes. The nun- 

 buoys are pear-shaped ; and the largest of 

 them are twelve feet long, and eight feet across 

 in the widest, and about two in the narrowest, 

 part. The can-buoy is like the nun-buoy, ex- 

 cept that it is wider at the top : both are 



Fig. 1. — Iron nun-buoy. 



widest at the line of flotation. In the oval 

 bottom a steel loop is cast, to which is append- 

 ed two fathoms of an inch-and-a-half stud 

 chain, to which is fastened a solid iron ballast- 

 ball of a thousand pounds weight, with two 

 loops cast in it at opposite sides. To the ball 

 is hung from fifteen to twenty fathoms of the 



