Vol. XXIII. No. 5.] 



POPULAE SCIETTOE NEWS. 



75 



also to the fires of Vesuvius, the ice fields and 

 glaciers of the polar regions, and even the re- 

 actions taking place on such an immense 

 scale in the sun itself. Like the law of gravi- 

 tation, the law of thermic equilibrium is uni- 

 versal, and in its application to chemical phe- 

 nomena, has opened up a new, and, as yet, 

 slightly exploited field, which promises rich 

 rewards to those who enter upon the work of 



investigation. 



<♦» 



SCIENTIFIC PUZZLES. 



FOR AMATEURS IN SCIENCE. 



We give below a few scientific problems, 

 which students, and others interested, may- 

 find pleasure and profit in solving. They 

 will bear considerable thought, and we shall 

 lie glad to hear from those who think they 

 have found the correct answers, before their 

 publication in the June number. A year's 

 subscription -will be given to the first (non- 

 professional) reader who answers them all 

 correctly. 



(i) Which weighs the most, a pound of 

 feathers or a pound of lead ? 



(2) The heat radiated from a stove will 

 melt a pound of ice ten feet distant in ten 

 minutes. IIow long will it take to melt it at 

 a distance of twenty feet.' 



(3) In a certain latitude the sun remains 

 above the horizon for three months, making a 

 da\- three months long. What is the length 

 of the next succeeding day .'' 



(4) It requires, approximatch', eight min- 

 utes for light to travel from the sun to the 

 earth. On the day that the almanac says the 

 sun rises at 6 A. M., at what time do we see it 

 rise, disregarding the corrections for refrac- 

 tion, etc. ? 



(5) A boiler having a capacity of five 

 hundred cubic feet, is entirely filled with water 

 under a pressure of one hundred pounds to 

 the square inch. The safety-valve is opened 

 till the pressure is reduced to ten pounds to 

 the inch. How much water will escape.' 



(6) A vessel connected with an air-pump 

 has a capacity of one cubic foot (1,728 cubic 

 inches.) The cylinder of the pump has a 

 capacity of 25 cubic inches. How many 

 strokes of the piston moving in the cylinder 

 will be necessary to completely exhaust the air 

 from the vessel .' 



(7) A vessel is completely filled with 

 water, in which a piece of ice is floating. 

 That part of the ice which is above the sur- 

 face of the water measures ten cubic inches. 

 When the ice is entirely melted, how many 

 cubic inches of water will have run over the 

 sides of the vessel ? 



(8) A barometer tube, containing a col- 

 umn of mercury, is attached, by its upper 

 end only, to a balance. The open lower end 

 dips into a vessel of mercury, in which it 

 moves freely. The weight of the tube is one 



pound, and that of the mercury contained in 

 it ten pounds. What will be the total weight 

 indicated by the balance } 



[Specially Reported for The Popular Science yetos.} 

 METEOROLOGY FOR MARCH, 18S9. 



TEMrERATlTRE 



AvEKAGE Thermometer. 



At 7 A. M. 

 At 2 p. M. 

 At 9 p. M. 

 Whole Month 



Last 19 Marches 



33 -06° 

 43-K)° 

 36-55° 

 37-63° 



.3»-53* 



Lowest. 



■i3 

 34° 



Highest. 



49 

 6o' 



49° 

 6o» 



I M-45' 39-lS" 

 I in 1872. in 1S7S. 



Range. 



26' 

 26' 



37 



14-73° 



The past month was the warmest March in 19 

 years, with a single exception, that of 1S78. and was 

 5. 10° above the average of those years. The lowest 

 points reached by the mercury was 23"-' on the first 

 and also on the 26th ; tlie coolest day averaged 30' 

 on the 9th ; several other days were nearly as cool. 

 The highest point reached was 60' , on the 24th. 

 which was also the warmest day, with an average of 

 50'^; the 23d, averaged 48 . The 20th had a range 

 of only one degree; the 21st and 6th were nearly as 

 iinifonii. The inost sudden changes of temperature 

 were 22*^ on the 23d and 21- on the 27th, each in 7 

 hours. The whole month was unusually mild for 

 March. 



SKY. 



The face of the sky in 93 observations gave 40 lair, 



13 cloudy. 27 overcast, 1 1 rainy, and 2 snowy, — a 

 percentage of only 43 fair. Ths average fair the 

 last 19 Marches has been 51. with extremes of 33.3 

 in 1881, and 63.4 in 1883. Only three Marches in 

 17 years have been less fair than the present, and 

 yet we had a few days very fine. 



PRECU'ITATION. 

 The amount of precipitation, including z'l inches 

 of snow melted, was 5.28 inches, while the average 

 in March for the last 21 years has been 579, with 

 extremes of i.iSin 1S85, and 10.22 in 1877. The 

 rainfall on the 5th and 6th measured 3.21 inches, 

 that on the 17th and iSth, 1.05. There was a trace 

 of snow on the 21st and 28th, and about z'i inches 

 on the 30th and 3i6t, mingled with rain, yielding 

 over one inch of water. 



PRESSURE. 



The average pressure the last month was 29.846 

 inches, a low average, as usual in March. The ex- 

 tremes were 29.00 on the 7th, and 30.40 on the ist, a 

 range of 1.40. The average pressure for the last 16 

 Marches has been 29.881, with extremes of 29 639 in 

 i88i, and 29.991 in 1882, a large range of .352 inch. 

 The sum of the daily variations was 5.85 inches, 

 givingan average daily movement of only .189 inch, 

 while this average is .239 in March, with extremes 

 of. 189 and .290. The largest movements were .44 

 on the 5th, .39 on the 14th, and .38 on the 30th. 

 The month began at the highest point of pressure, 

 and, by a gradual descent, reached the lowest point 

 on the 7th; it then rose gradually till the 15th with 

 but one falling observation, alter which it descended 

 till the 2ist, when elevations and depressions be- 

 came more irregular and frequent. 



WINDS. 



The direction of the wind in 93 observations gave 



14 N., I S., 12 E., 22 W., 20N. E., 15 N. W., I S. E., 

 and 8 S. W., — an excess of 39 northerly and 12 

 westerly, over the southerly and easterly, — indicating 

 the average direction of the wind the last month to 

 have been \V. 72"^ 54' N. The westerly winds in 

 March have uniformly prevailed over the easterly, 

 with a single exception (1S70) for 20 years by an 

 average of 38.3 observations, and the northerly over 



the southerly, without an exception, by an average 

 of 24.8, indicating the approximate general average 

 direction in March to be W. 32" 55' N,, showing 

 that the winds the past month have been 40° more 

 northerly than usual. The relative progressive dis- 

 tance travelled by the wind the past month was 40.81 

 units, and during the past 20 Marches 912.3 such 

 units, an average of 45.62, showing more opposing 

 winds the past month than usual. 



While the past month has been more cloudy than 

 usual, and the winds far more northerly, yet it has 

 been much warmer than the average, owing, prob- 

 ably, to the preceding warm winter, leaving little 

 frost in the ground. Hence the spring is opening 

 three or four weeks earlier than usual. D. W. 



Natick, April 5, 1889. 



[Specially Computed for The Popular Science A>ws.l 

 ASTRONOMICAL PHENOMENA FOR MAY, 

 1889. 

 Merci'RV is an evening star throughout the month. 

 It attains its greatest theoretical brilliancy and 

 passes perihelion on May i, but is then too near to 

 the sun to be seen without a telescope. It comes to 

 its greatest eastern elongation on May 24, when it 

 sets a little more than an hoiu- and a half after the 

 sun, and it can probably be .seen on any clear even- 

 ing during the latter half of the month, low down 

 in the western sky, soon after suiTset. Venus passed 

 inferior conjunction with the sun on April 30, and 

 became a morning star. The distance between the 

 planet and the sun rapidly increases, and by the end 

 of May, Venus will rise about two hours before the 

 sun. It attains its greatest brilliancy early in June. 

 Mars is too near the sun to be easily seen, and the 

 distance rapidly decreases, so that at the end of the 

 month they are about 5° apart. Jupiter is getting 

 into better position for observation. It rises in the 

 southeast at about midnight on May i, and about 

 two hours earlier on May 3t. It is in the constella- 

 tion Sagittarius, and moves westward about two 

 degrees during the month. The moon passes quite 

 close to the planet on the evening of May 17, and 

 the planet is occulted in some parts of the earth, but 

 not in the United States. The following eclipses of 

 Jupiter's satellites are visible in the United States, 

 (not all in the same part, however; an eclipse may 

 be seen in Boston which takes place before Jupiter 

 rises in California, and one may be seen in Califor- 

 nia which cannot be seen in Boston, because it takes 

 place after sunrise in the latter place.) The phe- 

 nomena all take place near the upper left hand 

 quadrant, as seen in an inverting telescope, and ye 

 all disappearances except one reappearance of the 

 third satellite. The times given are eastern stand- 

 ard : 



I. D. May 2, 6h. 6m. A. M. 



II. D. May 3, 6h. 57m. A. M. 



I. D. May 4, I2h. 35m. A. M. 



in. D. May 7, 5h. mi. A. M. 



III. R. May 7, 7h. 37m. A. M. 



I. D. May ii, 2h. 29m. A. M. 



I. D. May 18, 4h. 22m. A. M. 



I. D. May 19, loh. 51m. P. M. 



II. D. May 21, ih. 21m. A. M. 



I. D. May 25, 6h. i6m. A. M. 



I. D. May 27, I2h. 45m. A. M. 



II. D. May 28, 3h. 55m. A. M. 



Saturn is on the meridian at 6h. 30m. P. M. on 

 May I, and is about two hours earlier on May 31. 

 It is in the constellation Leo, about I2° west of the 

 first magnitude star Regulus (Alpha Leonis), and 

 during the month moves slowly toward it. Uranus 

 is in the constellation Virgo, and crosses the merid- 

 ian at about loh. 30m. P. M. on May i, and at about 

 8h. 30m. P. M. on May 31. It is 3° or 4° northwest 

 of Spica (Alpha Virginis), and is moving slowly 

 westward. Neptune is is conjunction with the sun 

 on May 22. 



