148 



NA TURE 



[June 18, [< 



elusions of much interest. He was also able to show, 

 both in the frog and mammal, the influence of the mid- 

 brain upon those movements. 



One of the most important pieces of work here 

 recorded is that in which Martin experimentally deter- 

 mined that the internal intercostal muscles are expiratory 

 in their function throughout their whole extent, thus 

 finally settling a question which ha<l divided physio- 

 logists ever since physiology was recognised as a 

 science. This he was enabled to do not by experiments 

 upon models, nor upon the cadaver, but by direct 

 observation in the living animal ; a method which will 

 always remain the only satisfactory one for solving such 

 problems. 



The physiologists of this country owe a debt of 

 gratitude to their .•\merican colleagues for having pro- 

 vided them in so handsome a form with this important 

 collection of monographs. E. A. Schafer. 



OUR BOOK SHELF. 



Atlas d Ostcoloi^ic. Ariiculaii07is cl Insertions Muscii- 

 laires. By Prof. Ch. Debierre. Pp. viii -f 92. (Paris : 

 Alcan, 1896.) 



This atlas contains 88 plates with 251 figures illustrating 

 the human skeleton. Figures are also given to illustrate 

 the ligaments of the various joints, and, further, for each 

 bone the muscular attachments are indicated by red 

 printing. The mode of development and microscopic of 

 bone are illustrated by five figures, and in a few cases a 

 certain amount of comparative osteology is introduced. 

 The figures are by no means better than those given in 

 the standard text-books, and it is a pity that no mention 

 is made in each case of the amount of reduction or magni- 

 fication made in the drawing. Some of the figures are 

 very confused, and the individual parts difficult to re- 

 cognise. This is especially the case with such figures as 

 the base of the skull with the soft parts left attached (Fig. 

 82). In many cases it seems a mistake that the figures 

 have not been drawn on a larger scale, as much room is 

 often wasted on the plates. 



Mechanics for Beginners. By W. Gallatly, M.A. Pp. 



253. (London : Macmillan and Co., Ltd., 1896.) 

 The special characteristics of this book are stated to be 

 (i) the large number of examples — eight hundred — of 

 which one hundred and sixty are worked in full ; (2) the 

 great attention given to work, power and energy ; (3) the 

 classification, in small sections, of problems of the same 

 type, the method of dealing with each section being 

 explained by a worked example. Teachers of elementary 

 theoretical mechanics will know how to appreciate these 

 important qualities of the book. The descriptions are 

 very clear, and the diagrams are helpful. The student 

 who uses the treatise as a te.xt-book, familiarising himself 

 with the illustrative examples, and working through only 

 a part of the well-selected and comprehensive exercises, 

 will be equipped for almost any examination in elementary 

 theoretical mechanics. .'Vnd he will, at the same time, 

 lay up in his mind a fund of useful knowledge. 

 Engineer Dratightsnien" s Work. By a Practical Draughts- 

 man. Pp.96. (London: Whittaker and Co., 1896.) 

 Students in technical schools will find in this book a 

 number of valuable hints on the use of mathematical 

 instruments and the work of drawing-offices. The 

 information is very elementary, but its character is such 

 that it will train young draughtsmen to be accurate and 

 methodical in their work. 



Forty-eight pages of advertisement are bound up with 

 the ninety-six pages of text. 



NO. 1390, VOL. 54] 



LETTERS TO HIE EDITOR. 

 [T/ie Editor docs not hotd liinisclf responsible for opinions ei- 

 pressed by his correspondens Neilhcr can he inulerta'.e 

 to return, or to correspond ivilh the writers of. rejeclei 

 manuscripts intended for this or any other part of NaturIv. 

 No notice is taken of anonymous communications.] 



Flying Engines. 



In the summer of 1893, I made some experiments on the 

 effect ijf .steam-j.icketing small steam-engine cylinders by 

 placing the whole of the cylinder and valve chest inside the 

 boiler ; the increase of economy was so marked, that I was led 

 to try whether a small toy engine could be made to sustain its 

 own weight in the air by the lifiingpower of an airscrew on the 

 crank-shaft. ■< 



Fig. I shows this little engine. The boiler is ot seamless 

 steel 2j" diameter, 14" long, and 'Ol" to 'Ois" inlhickness ; the 

 steam cylinder, single acting, li" diameter by 2" stroke, and 

 about "03 thickness of tool steel ; the piston is of thin cup form, 

 also of tool steel : the admission valve is cylindrical, ^V' diameter, 

 cutting off at ^ stroke. The whole of the valve and cylinder 

 are within the boiler. Some parts of the engine were soft 

 soldere<l, and some hard soldered ; the screw is of cane covered 

 with silk. The working pres.sure was limited to about 50 lb. per 

 square inch. The total weight of the apparatus, with water, as 

 in Fig. I, is 1:1 ' 



Fig. I. — Steam engine and boiler working lifting ^crew ; large plane to 

 prevent rotation of boiler ; total weight li lb. I.H.P. de\eloped, J, 

 Raised itself about 12 feet in the air. with steam contained in boiler. 

 No tiring after start. Initial pressure 50 lb. Ma.\imum revolution about 

 1200 per minute. 



Steam was raised by placing the boiler over a spirit-lamp, antl 

 when 50 lb. was registered on the gauge, and the engine 

 started, it raised itself in the air vertically to a height of several 

 yards. The revolutions of the engine were about 1200 per 

 minute, and the i.h.p. \ horse-power. 



The same engine was then mounted on a framework of cane, 

 covered with silk, forming two wings of II feet span, and a tail, 

 the total area being about 22 square feet. The total weight was 

 now 3i lb., and when launched gently from the hand in an 

 inclined horizontal direction it took a circular course, rising to 

 a maximum height of about 20 feet. When the steam was 

 exhausted, it came down, having traversed a distance of about 

 100 yards. 



Fig. 2 shows the machine in mid-air. The photographs 

 were taken by Mr. Gerald Stoney. 



Considering the primitive construction of the apparatus, the 

 result clearly showed that flights of considerable distance, pos- 

 sibly some miles, were quite possible with a small economical 

 steam-engine mounted on aeroplanes. 



The boiler was also found to be able to steam the engine con- 

 tinuously by using methylated spirits intead of water in the boiler. 



