Jan. 20, 1888.] 



SCIENTIFIC NE^VS. 



69 



TECHNICAL EDUCATION NOTES. 



Photographic College. — Next March an institution for 

 teaching photography in all its branches will by opened in 

 Vienna under the directorship of Dr. Eder. 



Paris — A School of Brewing. — The Minister of Agricul- 

 ture has ordered the immediate formation of " Laboratory 

 Schools of Brewing, Distilling, and Sugar Making." 



France. — A project for enabling rural schoolmasters to 

 devote several hours a week to the teaching of agricultural 

 science and agricultural account keeping is under the con- 

 sideration of the Minister of Public Instruction. 



School Board Evening Classes. — The evening classes 

 established by the School Board for London in 1882 have 

 each session greatly increased in number and in the effective- 

 ness of their work. In the present session classes have been 

 opened in no less than 128 schools, and more than 10,000 

 pupils have enrolled themselves. The subjects are varied as 

 much as possible to meet the requirements of individual 

 pupils, and are taught in an interesting and attractive 

 manner. The Recreative Evening Schools Association, 

 whose President is her Royal Highness Princess Louise, is 

 rendering the Board great assistance in this work. The fee 

 is, as a rule, only 3d. a week, and a great reduction is made 

 if paid quarterly. 



The Niagara Suspension Bridge. — A short time ago 

 a very interesting paper was read by Mr. Buck before 

 the American Society of Civil Engineers, describing the 

 operation of replacing the old masonry towers of the 

 Niagara suspension bridge by wrought iron towers. The 

 original towers were ninety feet high on the American 

 side, and eighty feet high on the Canadian side, the top 

 of each being covered with a cast iron bed for the sup- 

 port of two cable saddles by means of interposed rollers. 

 The masonry very soon after completion began to show 

 signs of failure, attributed by the author to a bending 

 strain from the elongation and contraction of the cables, 

 which gave a movement to the saddles amounting to 

 two inches from temperature and five-eighths of an inch 

 from live load. These failures continued, and became 

 alarming about two years ago, when it was resolved to 

 substitute iron towers, the order being placed with the 

 Detroit Bridge and Iron Works. Each tower is made 

 up of four wrought iron columns braced transversely and 

 longitudinally by wrought iron struts and rods, the base 

 of the columns resting on a limestone pedestal capped 

 with granite. As the cables could not be disturbed, it 

 was necessary to retain the old saddles, and merely 

 replace the support below and transfer the load to the 

 new iron columns. This was done by means of a trans- 

 ferring apparatus consisting of six jacks raising a frame- 

 work of short girders, to which the old saddles were 

 lashed by steel wire, the core holes in the saddles being 

 used for threading the wire through. Each jack was 

 worked by a man, and after the saddles had been 

 sufficiently raised, the lifting frame was shored up by 

 cast iron columns and the jacks removed ; the old base 

 plate and about three courses of masonry were then 

 removed, and a new built-up main bed, measuring nine 

 feet by five feet, and three feet eight inches high, and 

 weighing about nine and a half tons, was introduced, the 

 ends resting on the girders connecting each pair of 

 columns. The roller bed and rollers were then inserted, 

 and the transferring frame was, by means of the jacks, 

 again let down, so as to bring the weight on to the new 

 main bed. The whole operation took eight and a half 

 hours for each pier, no trains being allowed on the 

 bridge while the transfer was being made. 



CORRESPONDENCE. 



The Editor does not hold himself responsible for opinio7is expressed 

 by his correspondents, nor can hetake notice of anonymous com- 

 munications. All letters must be accompanied by the name and 

 address of the writer, not necessarily for publication, but as a 

 guarantee of good faith. 



THE INTELLIGENCE OF BIRDS. 

 A grey African parrot, which I have the pleasure of 

 knowing intimately, when she hears the doors being locked 

 and bolted at night, always cries out emphatically, 

 " Good-night," often adding, " Polly wants to go asleep," 

 expressions which she never uses at any other time. If 

 she sees the daughters of the house equipped for a walk, 

 she very frequently asks, " Are 00 going out ? " Once 

 or twice on seeing water drawn from a tap, she has cried 

 out, "Water, water ! Polly wants ! " Now the fact of her 

 uttering these phrases only when they are appropriate proves, 

 in my opinion, that she rightly connects them with the 

 several occasions. Aricola. 



COLOUR SENSE OF ANIMALS. 

 Sir John Lubbock's attempt, to train dogs to distinguish and 

 remember colours seem to have been unsuccessful. It will pro- 

 bably be found that in mammalian animals the colour sense 

 is less developed than in birds. But horned cattle evidently 

 possess some degree of the recognition of colour. It is 

 well known that they, especially hulls, are moved to anger 

 at the sight of any scarlet or bright red object. This fact 

 proves, it would seem, that they can distinguish a bright red 

 from the brown-reds so common in their own species. Has 

 a bull ever been known to manifest anger at a field full of 

 scarlet poppies ? S. O. 



SUN-SPOTS AND GRAIN PRICES. 



One naturally asks the question after reading this 

 heading, " What connection can exist between sun-spots and 

 grain prices ? " 



It is an astronomical fact that there is a regular periodicity 

 of the sun-spots ; and physical observers have noticed the 

 same periodicity in the variations of the earth's magnetism 

 and in the brilliancy and number of auroras. It is a question 

 worth looking into whether the regular periodicity ot eleven 

 years in the sun-spots has any effect upon the value of agri- 

 cultural produce, so eminent an authority as Professor Jevons 

 holding that opinion. 



Mr. Chambers, the Bombay meteorological reporter, has en- 

 deavoured to trace a connection between the recurring eleven 

 years of sun-spots and the variation in the price of millet for 

 every year of the last century in one of the larger provinces 

 of India. 



He expressed the prices in pounds-weight for a rupee, 

 the number 125, for example, meaning that the number of 

 pounds of grain for a rupee in that )-ear was 25 per cent, 

 greater than the corresponding eleven-yearly average. He 

 arranged theyears from 1 783 in nine groups of eleven years each, 

 and put down the numbers for the several years. On examin- 

 ing thetable, we find years of high and low prices recurring with 

 some regularity — five consecutive years being good years, 

 when money prices were below the average, and the six 

 following years being bad years when monej- prices were 

 above the average. 



Now, not only is there a regular period for the maximum 

 of sun-spots, and a regular period for the maximum of grain 

 prices ; but these maximum periods coincide. Amid all the 

 apparently irregular fluctuations of the yearl}- prices, there is 

 in every one of the ten Indian provinces a periodical rise and 

 fall of prices once every eleven years, corresponding to the 

 regular variation which takes place in the number of sun- 

 spots during the same period. The data, in fact, warrant the 

 conclusion that if it were possible to obtain statistics to show 

 the actual yield of the crops of each year, the eleven 

 yearly variations calculated therefrom would correspond with 



