March 12, 1903] 



NA TURE 



441 



" Literature of Europe," referring to Leonardo, says 

 the discoveries which made the names of Galileo, 

 Kepler, Castelli and others famous, the system of Coper- 

 nicus, the very theories of recent geologists, were 

 anticipated by da Vinci within the compass of a 

 few pages, not perhaps in the most precise language, 

 or in the most conclusive reasoning, but so as to 

 strike in with something like the awe of preter- 

 natural knowledge. 



Leonardo da Vinci in his writings deals with and 

 explains the formation of rain drops, the capillary 

 action of liquids, the equal pressure of water in closed 

 vessels, anticipating the application of this principle 

 as carried out nearly three centuries later by 

 Bramah in his hydraulic press. The theory of the 

 motion of waves in water is fully dealt with. The 

 illustration he gives of a field of corn under the in- 

 fluence of the wind when a wave motion traverses 

 the field without the stalks moving, to show the 

 action of the water in similar circumstances, has 

 been often used since, and was adopted by Scott 

 Russell in his report to the British Association on 

 waves in 1836. 



Leonardo da Vinci appears to have devoted much 

 attention to the use of mechanical appliances for 

 saving labour in the excavation and removal of earth 

 in the various canals that he was engaged in con- 

 structing. He was the first engineer to adopt the 

 use of weirs and locks for overcoming the varying 

 levels of the country through which his canals were 

 carried. A sketch of a pair of lock-gates (Fig. 1), as 

 used on the canal from Ticino to Milan, called the 

 " Naviglio Grande," as given in his " Codice Atlan- 

 tico," is here reproduced. Gates of almost similar 

 design may still be seen on many of the older canals 

 of this country, where locks were not made use of 

 until 1566. As specimens of the sketches of 

 mechanical contrivances given in his treatise, the 

 illustration of machinery for raising heavy weights 

 (Fig. 2) bears a strong resemblance to appliances to be 

 found amongst contractors' plant of the present day. 



The theories set out by Leonardo da Vinci, and 

 his laws for regulating the flow of water in open 

 channels as derived from his own practice and obser- 

 vation, for ascertaining the velocity of discharge due 

 to the balance of forces established between gravity 

 and friction, as to the effect of the junction of two 

 waterways, and the velocity of movement of water 

 as affected by the form of the channel and the depth 

 of the water, anticipated by fully a century the works 

 of Gug'liemini, of Paul Frisi and Castelli, to whom, 

 generally, has been given the credit of first deter- 

 mining the problems of hydrology. 



THE PHYSIOLOGICAL LABORATORY OF 

 THE UNIVERSITY OF LONDON. 



IT was the fear of some of those most interested in 

 the renaissance of the University of London that 

 the good effects of the transfer from Burlington 

 House to the Imperial Institute would not become 

 apparent until many years had elapsed. As 

 scientific research is more and more taking its proper 

 place as the highest duty that a university can per- 

 form, it is very gratifying to learn that the University 

 of London has seized a favourable opportunity, and 

 utilised its enlarged premises to this end. Even 

 though this laudable endeavour must be at present 

 regarded in the light of a preliminary experiment not 

 yet included in any authorised programme, the 

 physiological laboratory tentatively initiated by the 

 University appears to be admirably adapted for the 



NO. I 74 I, VOL. 67] 



purposes to which it is applied, namely, for lectures 

 on advanced physiology and for physiological research. 

 But its chief value is as a concrete object-lesson of 

 what the well-wishers of education in this country de- 

 sire to see promoted by the University of London, 

 and we are inclined to add, with bated breath, fed 

 from the national exchequer. A municipal body may 

 be expected to realise the importance of technical 

 science, and to pay for its establishment. But it re- 



7 (The Lecture Room). 



quires outlook towards a wider horizon to realise that 

 apparently useless knowledge is in reality knowledge 

 of which the reward is to be received by future 

 generations. 



The habitation of this infant laboratory at present 

 comprises the top floor of one side of the main building. 

 A long corridor extends throughout its whole length, 

 and the various rooms open from this right and left. 

 The first, counting from the entrance, is the work- 

 shop, where a 1 h.p. dynamo provides power for 



Fig. 2. — Room No. 19 (General Laboratory). 



the various tools used in constructing the smaller 

 apparatus required from time to time. Next is the 

 lecture theatre, with seats for eighty students. Ar- 

 ranged for lectures in advanced physiology, this ac- 

 commodation has so far proved sufficient ; the average 

 attendance has been about thirty, and as no attempt 

 has been made to give merely popular demonstrations, 

 and as only students are invited who already possess 

 some knowledge of the subject, these numbers are very 



