Science Siftings

New Zealand Tablet, 15 March 1917, Page 51

Science Siftings

Cutting a Bullet Out of the Heart. Dr. Maurice Beaussenat, who had already extracted a piece of grenade from the right ventricle of a man's heart, told the French Academie des Sciences recently of a second similar operation performed with success. A corporal wounded at Eparges had been treated for peritonitis and then had been • operated on for appendicitis. He continued to suffer in various ways for more than a year, when a radioscope revealed the pressure of a shrapnel ball, moving in time to the beatings of his heart. Supposing this to be in the pericardium or sac about the heart, Dr. Beaussenat ' went in,' as the surgeons say, and saw that the ball was actually in the right ventricle, near the lower end. The heart was drawn out; its wall was cut open between two loops of wire ; the ball was removed and the heart was sewn up again. ,Six months later the heart had healed so perfectly that there was not a sign of irregularity about its pulsations. Electricity from Peat. European engineers are engaged at present in the investigation of methods of utilising peat as fuel in electric stations. Southern Bavaria, for instance, has vast peat fields which would serve to run electric plants of large size and this would give a great reserve of power. The peat bogs lie mainly in the region of the Danube, and are estimated to cover an area of 500 square miles. Supposing the peat layer to be only 3 feet in thickness and the cubic foot of peat to afford but 3 pounds of fuel, this will mean a supply of 50 million tons. With the operation of extracting the peat regularly carried on during the year for 300 days, this can afford 700,000 horse-power in the space of 50 years. The fuel can be burned under boilers or itcan be used in special producers to secure a supply of gas for industrial purposes. A Wonderful Machine-Gun. Referring: to a recent article on machine-guns, a sergeant in the Australian forces sends us some interesting facts concerning the latest machine-gun adopted by the War Office. It is known as the Caldwell machinegun, being named after its inventor, a mechanic of Victoria, Australia. It can fire at the rate of 1000 shots per minute (it is said the speed has been increased to 1800 shots per minute), has two barrels, which can both be fired independently of the other and is air cooled, which does away with the necessity for carrying water to cool the barrel while working. Caldwell, according to our correspondent, sold the patent rights of this gun early this year to the War Office for the sum of £65,000 and .£5 royalty on each gun manufactured, and has been appointed manager of the workshops where they are turned out at a salary of £IOOO a year. After a Century. An atmospheric engine that has been in service hoisting coal at a colliery near Rutherglen, Scotland, since 1809, has just been discarded to make place for a steam engine of a modern type. During the 106 years that it was in service this interesting relic of the early days of steam is reported to have given entire satisfaction and to have required no renewals other than that of two spur wheels that were broken by accident. The atmospheric engine represents one of the earliest successful attempts to make practical use of steam power. Steam at a pressure little greater than that of the atmosphere was used, and simply performed the work of pushing the piston to the upper end of the cylinder. In this work it was assisted by a weight hung to the opposite end of the walking beam operated by the piston. As the piston reached the upper end of the cylinder the valve was closed, and the steam in the cylinder was condensed quickly by a jet of cold water. This operation created a partial vacuum so that the piston was forced back to its original position by the pressure of the air, the water being then forced out of the cylinder by the incoming steam at the beginning of the next upward stroke.