Alexander Graham Bell's Ice Stove A FEW weeks ago we published an article by Mr. W. A. Dupuy on Alexander Graham Bell's ice stove. One of our subscribers has suggested that we publish a picture of the arrangement, so that others may profit by Dr. Bell's ingenuity. The accompanying engraving is the result. As our readers will remember, Dr. Bell converted his swimming pool into study and living room. Pipe A discharges at A' cold air from an ice-box B into the lower portion of the swimming pool. In the pipe A is placed an electrically operated fan C, which receives the air from the ice box E, which may be an ordinary ice box, and the air in the pipe D leading to the box E for supplying frosh air has a suitable valve E, by which the supply of fresh air may be regulated. The drawing shows the ice box in a small room adjoining the swimming pool. A Small Portable Ice Machine THK modern tendency is toward large scale production. ''he spinning-wheel may be seen in our homes as an heirloom, but it is silent and unproductiV(. We Jind it cheaper lnd better to have our industries concentrated in large factories, which turn out our cloth·· ing, our prepared foods, our ice and what not in bulk. Nevertheless, home “manufactures” have not yet quite passed away, and naturally they too have been modernized by calling to aid the various resoureos which the development of mechanical and other arts place at our disposal. An instance in point is the ice-making machine shown in our accompany- I ing illustration. This depends for its | action upon tlw well-known fact, that a liquid in evaporating absorbs from its surrOdings a certain quantity of heat, eommonly termed the “latent heat of evaporation,” thorehy cooling those surroundings. In order to apply this fact to practical advantage, we need a container from which a suitable liquid, such as water, is evaporated, an air pump wherewith to reduce the pressure above the liquid, so as to cause its evaporation at low temperatures, and finally some absorbent to take up the vapor, and assist in maintaining a low pressure in the apparatus. Heferring to our illustration, the rotary pump will be seen at the 10r on the left, eonIlected by a ruffer suction pipe to the “ absorber.” This latter is simply a glass vessel containing commercial concentrated sulphuric acid, which should be free from hydrochloric acid. The purpose of the sulphuric acid is to take up the vapor evolved from the water placed in the vessel (a carafe in our drawing) which is being cooled. This vessel is connected to the absorber by an enamelware tube with rubber ends. A block of ice may thus be formed directly in a carafe of table-water, or a suitable wide-mouthed vessel with adaptable cover may be substituted for the carafe, and any material, such as ice-cream mixture for example, can be frozen. The Ventila tion of Sle eping Cars W HEN” Dr. Lorentz, the famous orthopaedic surgeon, was in this country some years ago, he expressed his astonishment that so ingenious and inventive a people should tolerate such an unsanitary abomination as the type of sleeping car used on American railways. What Dr. Lorentz complained of particularly was the lack of ventilation. That subject was ably discussed in a paper by Dr. Thomas R. Crowder, which was read before the annual meeting of the Ameriean Public Health Association. Apparently, the ideas of Dr. Lorentz are all wrong. Dr. Crowder says: “According to the older theories, the sensations of discomfort arising in inclosed spaces had their origin either in an excess of carbon dioxid or an insufficieney of oxygen. Pettenkofer I cast the first serious doubt Oil the (,orreetness of these theories. Hermans proved that air containing 15 per cent oxygen may contain 2 to 4 per cent carbon dioxid and not be harmful. On removing the carbon dioxid there was no great discomfort even when the oxygen was reduced to 10 per cent. "It seems to be established beyond reasonable doubt that discomfort is not due to any change in the chemical composition of the air, but to physical changes only; and that to maintain a normal heat interchange between the body and the air is to avoid the development of those symptoms which are eommonly attributed to poor ventilation. A certain amount of fresh air must be supplied, of course, but the most vital element of the ventilation problem becomes that of regulating the temperature of the air. The question of how to ventilate a railway car is therefore chiefly a question of how to regulate its heat." In cars which are close or stuffy, Dr. Crowder says, the temperature is invari- ably high. What is more, a high temperature renders odors more noticeable. The most marked offensiveness that he had ever noticed was in a day coach, where the air was in such a degree of chemical purity as to indicate ideal ventilation by any standard that has ever been proposed. ----------------------------------------------------------------------------------------------------------------------1 The car was hot and many filthy people in it. On the other hand, with perfect comfort has been sometimes associated the highest chemical impurity. "It seems probable, furthermore, that one main cause of the complaint of poor ventilation in the sleeping-car berth is purely psychic. We are used to sleeping-rooms with walls and ceilings far from us. In the berth they are very close. Their very nearness is oppressive. It seems as if there cannot be enough air in this small space to supply our wants. The sensation is often quite independent of the amount of air supplied and even of the temperature. "Even under the older applied principles of ventilation, the air-supply of sleeping-cars, as determined in this study, is ample under nearly ni eonditions. The average carbon dioxid in the air of running cars falls well within the limits of contamination permitted by the earlier investigators, and it is relatively rare that the individual t- I observations show more than 10 parts i e 10,000. In the light of the newer concep d tions, which have as yet been applied ii e praetiee only to a very limited extent, thi il air-supply is ample under all condition y observed. No danger to health is to b< 1. apprehended under the conditions ordi narily obtaining even in still cars. Thei are occupied only for short periods as ; rule and are not uncomfortable if kep cool." In Dr. Crowder's opinion, “the result! obtained by the type of exhaust ventilatoi which is now a part of the standard equip ment of the Pullman cars, are entirel adequate to meet the demands of hygiene and that those difficulties and discomforts which do sometimes arise are due to othej causes than lack of a sufficient amount ol fresh air or to excessive vitiation. It is extremely unlikely that increasing the air-supply, which now amounts to from six to ten or more times tl]e cubic content of the car each hour, and must maintain considerable motion of the atmosphere, would aid in any other way than by making overheating more difficult to bring about. “Overheating is the paramount evil. I1 is the thing to be chiefly guarded against in the attempt to maintain comfort and good hygiene. It is not feasible to coo] the naturally overheated air in summer, or e to dry it when excessively humid. Fan t motors and open windows are the available 11-1 ,1 !•«.,,• means by which the difficulties arising in hot weather may be most readily over- . come. Carry away the body heat as t . .-,-,, , , rapidly as possible by a strong current of r . air. Though the avoidance of overheating in winter would seem to be an easy thing, its accurate control to meet the rapidly changing conditions under which cars may , be operated is a matter of great difficulty. lt-,. , , , . . Experience has shown that it is necessary . to have in sleeping-cars at least twice as t , ,. . . -, , , . much radiating surface as is demanded in common practice for heating the same s space in houses; this in order to warm the , ! O .11,.-, large volume of air received and discharged so that it will maintain comfort to inactive passengers. To decrease this surface would be to fail to maintain a sufficiently high temperature on occasion. A system is needed capable of being quickly and effectively controlled to meet l . 1, , • T.- n, n rapidly changing conditions. Such a system is now being experimented with in which there are multiple units of radiating surface, each with a separate control. The results so far indicate that from this a more uniformly comfortable condition can be maintained." Notes for Inventors Running a Typewriter With a Perforated Roll.—The problem of manifolding typewritten letters has given inventors no little concern. It frequently happens that thousands of letters, all of them alike, are sent through the mails, letters which are in reality eirculars in epistolary form, each of which must appear as if it were intended only for the particular recipient into whose hand it falls. 'he market is now almost overcrowded with duplicating machines of various kinds, which imitate, with more or less success, typewritten work. One of the most ingenious solutions is the application to the typewriter of the perforated paper roll, which has made the automatic piano player possible. As might be expected, the inventor who has done this, Mr. John McTammany, has been identified with the automatic piano player ever since its inception. In fact, he has good reason to regard himself as a pioneer inventor of the automatic piano player. Mr. McTammany has invented a machine which is to be used 106 SCIENTIFIC AMERICAN July 29, H 1 in connection with the ordinary typewriter, and which may be best described as the mechanical equivalent of a pair of hands, capable of turning out ten thousand letters a day. Each letter is an original. As in the automatic piano player, a perforated paper sheet is used. This sheet, whose perforations correspond with certain letters on the typewriter keys, however, does not cause a series of pneumatics to operate, in order to depress the keys of the typewriter, but controls a series of star wheels whicl: actuate the keys. The paper strip is positively fed. By abandoning the pneumatic system of the piano player and yet retaining the perforated roll, the inventor has succeeded in producing a machine which is remarkably compact. Appreciation of Invention.-It is interesting to note the importance ascribed to inyentors and invention in practically all discussions of the developments of business. In a recent article in a popular magazine along the line of business aids and occupying only four short columns, we find reference in three of the columns to three separate inventions, two of which were made by attaches of the same business establishment, which is described as encouraging and assisting originality in inventions that can be patented. In explaining his advancement, one of the successful men in the big establishment is quoted as saying that he began making inventions or improving some inventions made by others, and that he was then engaged in the development of another invention. A Mechanical Violin.-An instrument in the general form of a piano, but seeking to secure the effect of a violin, is sought in a patent, No. 996,614, to Andrew M. Carlsen of St. Paul, Minn. He provides in connection with a stringed instrument like a violin two bows near each other upon the same string. These bows are reciprocated in contact with the string slowly at the same speed in one direction and for a part of the stroke simultaneously and are given a more rapid return movement. During the slow movement in contact with the string, the bows are applied to the string partly one at a time and partly both at the same time, so that each bow will continue the note the previous bow is playing before the previous bow leaves the string to make its quick return stroke. A keyboard is provided for pressing mechanical fingers against the strings by power, and this keyboard controls the power so it is applied to the right fingers and at the right time. An Advertising Device.-In a patent No. 996,929, to Charles W. Saalburg of New York as assignee of Hans Kempinski of Berlin, Germany, is shown an exhibiting device for use in show windows and similar places, including a tank and a bottle above the tank and tilted to discharge liquid into the tank. Liquid is supplied to the bottle by a tube extending upwardly from the tank and through which the water from the tank is forced by a pump. The tube enters the neck of the bottle and the tube is bent between the tank and bottle to conform to the trajectory formed by the liquid pouring from the bottle into the tank so the tube will be within and concealed by the stream of liquid falling from the bottle. Six Patents to One Inventor.-WilHam D. Forsyth of Youngstown, Ohio, recently obtained on the same day six patents numbered from Nos. 996,629 to 996,634 inclusive. Two of these patents are for metallic railway ties, one for a brake beam, one for a rail joint, and another for a reinforced concrete cross tie, and one for a truck side frame for cars, the latter being assigned to A. M. Neeper of Pittsburg, Pa. It will be noticed that all of the patents relate to the rolling stock or the roadbed of a railway. A Combined Flying Machine and Parachute.-A flying machine whose planes normally assume a comparatively flat form, but which can be distorted by mechaniRm controlled by 1,he avi a tor into the form of a parachute, is presented in a patent, No. 997,122, to Otto A. Fenn of New York. A Novel Ice.machine.-A patent, No. 993,771, has been issued to Joseph D. Gallagher, of Glen Ridge, N. J., assignor to a New Jersey corporation, for an apparatus for making plate ice including a tank and a vertically arranged freezing plate, combined with a band saw and operating means for the band saw and means for feeding the band saw upwardly in order that it may sepll'a.te the cake of ice from the freezing plate. A Guard for Stick Pins. - stick pin fastening forms the subject of a patent, No. 996,298, to Adinius R. Sunde, of An-toni to, Colo., its novel feature being a retaining prong at the back of th< head of the pin and spaced away from the head so that, when inserting the pin, the head can be turned slightly to thro,: the prong away from a neck tie and when the pin is inserted, the head can be partially rotated to force the prong horizontally in to the tie. A New Hydraulic Ram.-An improved hydmulic ram is presented in a patent, No. 996,056, the invention of Edward R. Brodton of Mobile, Alabama. In this patent a water wheel is placed in the casing of the ram and the waste valve of the mm is operated by the water wheel to closed position, the nOI\al tendency of the valve 'eing toward open position. A Patent to Edison. -Thos. A. EdisQn has obtained a patent, No. 996,070, for a rotary kiln for cement. The kiln comprises a long tube wihich is rotated and has a combustion portion at one end. At its other or upper end the tube is of a greater diameter and is divided into a number of passages. Patents Assigned to Large Companies. -Nothing better illustrates tle high estimate in which patents are held by the business public than the attitude toward them of la-roge business corporations, such, for instance, as the General Electric Company, the Westinghouse Co. and the United Shoe Machinery Co. It appears from the list of patents issued June 27th, 1911, th a t on that day alooe four patents were issued to the United Shoe Machinery Co., as assignee, while on the same day more than thirty patents were issued to the General Electric Co., as the assignee of various inventors including among the number such distinguished inventors and scientists as Elihu Thomson and Oha'S. P. Steinmetz. A Portable Bathtub.-In traveling in remote sections bathing facilities are not always available. Warren C. Callahan of Louisville Ky., provides for this in a patent, No. 996,453, by a portable bathing apparatus in which a hoop made of I number of flextbly connected sections so it Ican be easily collapsed by swinging the sections face to face for convenience in carrying, is set edgewise and a water proof cloth is placed over the hoop and depressed within the hoop so the interior of the hoop forms a tub to hold the water while bathing and the edges of the sheet can after the bath, be brought together forming a water bag to carry the water to a disposal point. New Wireless Patents.-A number of patents, Nos. 996,088 to 996,092 inclusive, have issued to Maurice Bernays Johnson of San Antonio, Texas, for inventions relating to wireless telegraphy and telephony. .one of these patents, No. 996,-089, is for a combined wire and wireless telephone system, and another, No. 996,-089, is for a combined wire and wireless telegraph system, the former including I wire line at the central station and wireless instruments also at the central station and arranged for connection with the wire line; and wireless communication is established between a transmitter at ane end of a space and a receiver and transmitter at the other end of the space, the latter receiver operating its transmitter, switches being pr0vided for conne(tiug the wire liD with the wirel!ss imtruments and for conneeting the wireless instruments with the central operator.