IN the accompanying illustration an interesting impression is conveyed of the development of the railway locomotive in Great Britain during a period of eighty years. Stephenson' s famous “ Rocket” is here shown in comparison with the latest type of London and Northwestern Railway passenger express traffic locomotive, “ W. C. Brocklehurst, No. 2155,” of the new “ George the Fifth” class, and their juxtaposition affords a comprehensive idea of the remarkable strides that have been made in railway engineering, upon British railways. The “ Rocket” was built in 1829, and took part in the famous contest at Rainhill, when the directors of the Liverpool and Manchester Railway, now forming part - of the London and N orth-western system, offered a prize of $ 2,500 for the purpose of deciding the question of the adaptability of steam locomotives for working railways. Five engines were entered in that classic competition, from which the “ Rocket,” as is well known, emerged victorious. It is interesting to compare the weight and speed of the train in this competition, which may be rewas not to exceed 50 pounds per square inch. In the actual trial the “ Rocket” attained an average speed of about 19 miles per hour while hauling a train weighing 13 tons. Stephenson' s engine had a cylindrical boiler measuring 6 feet in length by 3 feet in diameter, with fiat ends, having 25 copper tubes of 3 inches diameter. The firebox was 2 feet wide and 3 feet high. The cylinders, two in number, were 8 inches in diameter, and had a stroke of 16% inches, while the diameter of the driving wheel was 56% inches. The engine exerted about 20 horse-power, and weighed 9,296 pounds, while the tender weighed about 7,168 pounds. The latest London and Northwestern engine standing alongside is one of the latest types of express engines used in this company' s express traffic. The two inside cylinders are each 20% inches in diameter, and have a stroke of 26 inches, with a boiler pressure of 176 pounds per square inch, or three and a half times that allowed in the “ Rocket.” The boiler is 62 inches in diameter, with a barrel 141% inches long, fitted tender 86,920 pounds, giving a total weight of 219,984 pounds. It is fitted with apparatus for picking up water from troughs while traveling at full speed. and has a tank capacity of 3,000 gallons, while it carries 7 tons of coal. In order to test the power and capability of this type of engine, the first locomotive built, the “ George the Fifth,” made an experimental run between Crewe and Euston, 158 miles, with a train composed of a dynamometer car and 13 8< wheeled corridor coaches weighing 357% tons, and with engine and tender weighing 4541.4 tons. On the out ward journey one stop was made at Rugby, the average speed between these points being 54 miles per hour, the highest speed recorded being 68 miles per hour. Between Rugby and Euston the average speed was 581.4 miles per hour, with a maximum of 73 miles per hour. The return journey from Euston to Crewe was made without a stop, which distance was covered from station to station in 2 hours 36% minutes, giving an average speed of 60% miles per hour, with a maximum speed garded as the standard for those early days, with those of modern times. It was stipulated in the 1829 competition that the successful engine, if it weighed 6 tons, should be capable of drawing after it, on a level plane, a train of the gross weight of 20 tons, including tender and water tank, at the rate of 10 miles an hour, while the steam pressure in the boiler with a steam superheating arrangement by means of which the temperature of the steam is raised to 650 deg. F. before being used in the cylinders. The firebox is 7 feet 4 inches long by 4 feet 1 inch wide cutside the casing. The coupled driving wheels are 81 inches in diameter, while the weight of the engine in working order is 133,064 pounds, and that of the of 78V:! miles per hour. These speeds and weights compared with what the “ Rocket” achieved illustrate strikingly the enormous progress made in one branch of railway engineering, and show the great facilities placed before the public for rapid transit from one point to another in these days, as compared with the condition in the early days of British railways. The Comets DR. WILLIAM R. BROOKS, director of the Smith Observatory, and professor of astronomy at Ho-bart College, Geneva, N. Y., discovered another comet on the night of July 20th. Its position was right ascension 22 hours 13 minutes 40 seconds; declination north 20 degrees 57 minutes. The comet is in the constellation Pegasus, and is moving slowly in a northwesterly direction. While not at present visible to the naked eye, it is a fairly bright telescopic comet, and its movements will be observed with interest. This is the twenty-sixth comet discovered by Prof. Brooks— a larger number than any other living astronomer has found. The Kiess Comet. A comet was discovered by Kiess at the Lick Observatory on July 6th in R. A. 4 h. 51 m. 51.8 s.; Dec. north 35 deg, 15 m. An observation of this comet was obtained by Dr. William R. Brooks at the Smith Observatory, Geneva, N. Y., on the morning of July 13th, in R. A. 4 h. 40 m.; Dec. north 34 deg. 1 0 m., which shows the motion of the comet to be southwest. It is in the constellation Auriga, and on the last named date about 11 degrees south of Capella. It is now a bright telescopic comet and has a visible tail. Artificial Measles in Monkeys MANY attempts have been made to cultivate the specific organism related to the cause of measles in the blood of such animals as are commonly used for experiments on serums and toxins, etc., but without success. About seven years ago an English experimenter tried in various ways to infect chimpanzees by injection of blood taken from a measles patient but got only negative results, Within the last year Dr. John F. Anderson, Director of the Hygienic Laboratory, and Dr. Joseph Gold-berger have carried on similar experiments with a number of rhesus monkeys. The blood used was drawn from measles patients. The monkeys showed rises in temperatures characteristic for this disease, and in a number of cases there were distinct eruptions on various parts of the skin. Two of the monkeys that showed distinct symptoms were held for the purpose of inoculating other monkeys, two new ones being inoculated from each. After a number of days, each of the monkeys showed definite reaction in temperature; one in each pair also showing an eruption • of the skin. From these experiments it may be hoped that further research in the attempt to obtain anti-toxic sera for measles, or at any rate further light upon the nature of the disease, win be more profitable for treating the malady, than th° se of the past.