Vol. XXn. No. 9.] 



POPULAR SCIENCE NEWS. 



139 



also been found that yeast will assimilate tar- 

 taric, malic, and even nitric acids, reducing 

 the last to nitrous acid. Truly, the little mi- 

 croscopic yeast-cell is a wonderful organism. 



There are several other varieties of fermen- 

 tation which are not so well understood, and 

 are of but little practical importance. The 

 acetic fermentation, or conversion of alcohol 

 into vinegar, is accomplished by a ferment 

 known as mother-of-vinegar, or Mycoderma 

 aceti; but it is a simple process of oxidation, 

 and can be accomplished equally well by inor- 

 ganic chemical reagents. Lactic fermentation 

 takes place when milk sours, and the sugar 

 contained in it is transformed into lactic acid. 

 Butyric acid is formed in the fermentation of 

 butter ; while putrefaction and decay are vari- 

 eties of the same process, and due, in part at 

 least, to the action of living organisms. Dis- 

 eases like t^'phoid-fever, diphtheria, or con- 

 sumption, in which bacteria are present, may 

 also be considered as a fermentative process 

 going on in the body. 



An}' substance that will kill the organisms 

 of fermentation will stop the process, and pre- 

 serve the substance indefinitely. Heat is the 

 safest and best agent for this purpose, and is 

 used to an immense extent in preserving 

 canned provisions. The list of chemicals 

 capable of stopping fermentation is a long 

 one, and includes sulphurous acid, borax, 

 saHc3'lic acid, carbolic acid, corrosive sub- 

 limate, thymol, and man}' others. Some of 

 these are harmless, and others poisonous ; but 

 none can be recommended as a wholesome 

 addition to food or drink for daily consump- 

 tion. 



♦ 



[Original in Popular Science yewa.] 



TO ASCERTAIN THE DISTANCE TO THE 

 MOON. 



First we require to mea-sure the angle made by 

 a straight line from the point of observation to the 

 moon, and another straight line from the earth's 

 centre passing through the point of observation to 

 the zenith. The visual ray from the observer to 

 the moon will be the first line OM in the figure 

 below. Any perpendicular, as a plumraet-line, at 

 O, the point of observation, will exactly coincide 

 with the straight line from the centre of the earth 

 to the zenith, the point in the heavens immediately 



overhead. The number of degrees in tlie angle 

 MOZ must therefore be accurately taken. When 

 that is done, we also know the value of the angle 

 MOC ; for that must be the diilerence between 

 MOZ and two right angles. If we then lay down 

 the lines ZC and MO at the ascertained angles, it 

 is evident that the line OM must pass through that 

 point in the heavens which is occupied by the 

 moon. Now let another observer at A in the same 

 manner ascertain the angles MAZ and MAC. He 

 will then be able to lay down two straight lines 



ZC and MA. If these are drawn at their proper 

 angles, the line AM must also pass through the 

 point in the heavens occupied by the moon. Now, 

 if these two observers come together, they will be 

 able to construct a four-sided figure MOCA. The 

 two lines DC and AC will represent two radii of 

 the earth. The two lines OM and AM will repre- 

 sent the distance from each observer to the moon. 

 If this figure is constructed accurately, it will be 

 found that MO or MA is sixty times longer than 

 OC or AC. That is, the distance to the moon is 

 sixty times greater than the radius of the earth. 

 The latter being known to be four thousand miles, 

 we have to multiply by sixty, which gives us two 

 hundred and forty thousand miles as the distance 

 to the moon. 



B. 



[Specially reported for tlie Popular Science ^ews.] 

 METEOROLOGY FOR JULY, 1888. 



TEMPERATURE. 



The entire month was the coolest July for the 

 last eighteen years, being 5.85 less than July, 1887, 

 which was the warmest during this period. July, 

 1884, was only .01° warmer than the present, — a 

 difference scarcely perceptible. July, 1876, was 

 also very warm, only .44° less than that of 1887. 

 The present July was only .17° warmer than June 

 last, while the average July is 4.52° above that of 

 June. The coolest day the past month was the 

 1st, with an average of 60§°. The 28th was nearly 

 the same, 61°. The 7th was the warmest day, 

 with an average of 76°; the next warmest 74°, on 

 the 11th, which was more than ten degrees below 

 that hottest day in June last. The general range 

 of temperature was less than usual for July, which 

 averages the lowest of any month in the year. 

 The more uniform the temperature, the smaller 

 the range. The temperature of the month was 

 2.46° below the average of July, and the average 

 since Jan. 1 about 1^° below the usual for the seven 

 months, keeping the season still backward. 



The face of the sky in 93 observations gave 53 

 fair, 21 cloudy, 16 overcast, and only 3 rainy, — a 

 percentage of 57 fair. The average fair for the 

 last 18 Julys has been 62.3, with extremes of 43 

 in 1887, and 76.3 in 1878. Only three Julys in 

 18 years have been less fair than the present. We 

 had several very fine summer days. The 3d, and 

 16th to 18th, were especially noted. 



PRECIPITATION. 



The amount of rainfall the past month was only 

 1.20 inch, the smallest amount during the last 20 

 Julys; while the average has been 2.99 inches, with 

 extremes of 6.85, in 1876, and 1.20, in 1888. This 

 small amount, following the small amount of June, 

 produced no inconsiderable drought, to the injury 

 of vegetation in general, and many fruits in partic- 

 ular. There were severe thunder-showers in the 

 vicinity on the 5th and 11th, but scarcely a trace 

 of rain fell here. The latter occurred at midnight, 

 attended with sharp and almost continuous light- 

 ning, heavy thunder, and severe wind, doing some 

 damage. Small amounts of rain fell on the 1st, 

 19th, and 20th, but little more than sufficient to lay 

 the dust. The principal fall was ou the 22d and 



23d, yet less than three-fourths of an inch. The 

 whole amount since Jan. 1 has been 29.71 inches 

 (mostly during the first three months), while the 

 average for this period in twenty years has been 

 27.61. 



PRESSURE. 



The average barometer the past month was 29.960 

 inches, with extremes of 30.20 on the 18th, and 

 29.42 on the 12th, a range of .78 inch. The average 

 for the last fifteen Julys has been 29.922, with 

 extremes of 29.976 in 1887, and 29.820 iu 1884. 

 The sum of the daily variations was 3.23 inches, 

 giving an average daily movement of .104 inch. 

 This average in 15 Julys has been .091, with 

 extremes of .118 and .074. The largest daily 

 movements were .40 and .32 on the 11th and 13th, 

 the former in connection with that severe thunder- 

 storm. 



WINDS. 



The direction of the wind in 93 observations 

 gave 12 N., 1 S., 8 E., 20 W., 8 N.E., 14 N.W., 5 

 S.E., and 25 S.W., — an excess of 3 northerly and 

 38 westerly over the southerly and easterly, and 

 indicating the average direction the past month to 

 have been AV. 4° 31' N. The westerly winds have 

 uniformly prevailed over the easterly by an average 

 of 43.37 observations; and the southerly over the 

 northerly, with the one exception of the present 

 July, by an average of 20.74, — indicating the 

 approximate general average direction of the wind 

 during the last 19 Julys to have been W. 25° 33' S., 

 and showing that the winds the past month have 

 been 30° 4' more northerly than usual. Hence, 

 too, the cool July. The relative progressive dis- 

 tance travelled by the wind the past month was 

 38.12 units, and during the last 19 Julys 913.3 

 such units, — an average of 48.07, — showing more 

 opposing winds the past month than usual. 



IN REVIEW. 



It may be observed that the present July was the 

 coolest during the last 18 years; had more northerly 

 winds than any in the last 19 years; and less rain 

 than any during the last 20 years ; with only three 

 Julys in 18 years less fair than the present. Surely 

 these peculiarities must have had a corresponding 

 influence on vegetation, not favorable to its high- 

 est perfection. D. W. 



Natick, Aug. 4, 1888. 



[Specially reported for the Popular Science News from the 

 Observatory of the College of New Jersey.] 



ASTRONOMICAL PHENOMENA FOR 

 SEPTEMBER, 1888. 



The Planets. — Mercury is an evening star, but 

 is too near the Sun and too far to the south to be 

 easily seen. Venus is also an evening star, and is 

 gradually increasing its distance from the Sun ; but 

 it is several degrees to the south, and sets only 

 about an hour after the Sun. Mars is still to be 

 seen ; but it now sets between 9A. and 9A. ZOm. p.m. , 

 and is growing much fainter. It passes conjunc- 

 tion with Jupiter on Sept. 11, the latter being a 

 little more than 2° to the north. Mars is moving 

 somewhat rapidly to the eastward among the stars. 

 Jupiter sets at about lOA. p.m. on Sept. I, and at 

 about 8A. 30m. on Sept. 30. It is moving somewhat 

 slowly eastward, and on Sept. 22 passes about half 

 a degree to the south of Beta Scorpii. The fol- 

 lowing eclipses of his satellites are visible in the 

 United States during the month. They take place 

 near the planet on the upper right-hand quadrant. 

 D denotes disappearance, and R reappearance. 

 Times are Eastern standard. 



I. R. Sept. 1, 9h. 7m. P.M. I. K. Sept. 17, 7h. 26m. P.M. 



I. II. Sept. 8, llh. 2m. P.M. III. I). Sept. 19, lOh. Om. p.m. 



II. K. Sept. 10, 8h. 14m. p.m. III. R. Sept. 19, llh. 58m. p.m. 



III. It. Sept. 12, 7h. 68m. p.m. I. II. Sept. 24, 9h. 21m. p.M 



