Dec. 5, 1884.] 



♦ KNOWLEDGE ♦ 



467 



would be irrigated, and thus favour the special conditions 

 for the propagation and dissemination of the deadly 

 bacteria. 



This leads us to observe that where the question of 

 outlay interferes with the employment of parquet floorings, 

 it is incumbent on the builder to pay special attention to 

 the construction of his floors. He ought either to have the 

 floor-boards accurately matched and fastened, to prevent the 

 after-effects of possible warping or shrinkage of the wood, 

 or he ought to have all the interspaces carefully caulked, 

 as on the deck of a ship. We shall revert to the employ- 

 ment of sanitary floorings in a subsequent chapter, wLea 

 we come to deal with the subject of house furniture. 



Closely related to ventilation and the exclusion or ready 

 removal of dust and dirt from a house, comes the considera- 

 tion of dour and window construction. Where no special 

 provision is made for the introduction and outlet of aii', it 

 usually happens that the defective fitting of doors and 

 windows is forced to fulfil those functions in a peculiarly 

 disagreeable manner. Not only do they ventilate the 

 rooms by constant draughty currents of air, but they 

 permit of the entry of damp, dust, and dirt from the 

 passages of the house, and even from the streets ; so that, 

 when we come to apply a reform to doors and windows, we 

 must look to the adequate admission of fresh, and the ex- 

 pulsion of polluted, air. To a large extent, the average 

 door and window would suffice, provided that the ventila- 

 tion is well attended to. The air would in such a case find 

 its way into the room more readily through a well-devised 

 inlet than by means of the adventitious chinks of doors and 

 windows. Yet, to provide against the extraordinary incur- 

 sion of air, the fitting of the latter ought to be as perfect 

 as jjossible. This, however, is not so easy to accomplish as 

 it would seem to be at first sight. The enormous expendi- 

 ture involved in the necessary outlay for thoroughly well- 

 seasoned wood and skilled, careful workmanship would 

 swallow up the profits of the builder in the erection of that 

 class of houses, such as artisans' dwellings, itc, which bring 

 him in his most easily-realised income. 



As a rule, the doors of houses, in the course of time, tend 

 to shrink ; and in such a way as to increase the space at 

 the bottom which has been left for the easy working of the 

 arrangement. Let us premise that the room or passage to 

 which the door gives access is provided with suitable ven- 

 tilators ; then the base of the door ought to fit so closely as 

 to prevent the entrance of draught, dust, or rain. Now, 

 apart from great expense, this is almost impossible to secure 

 in ordinary joinery, inasmuch as the wear and tear of the 

 floor would alone suffice to renew the evil in the course of 

 time. It is possible, however, to adapt a movable piece to 

 the basal edge of the door which shall be simple, self-acting, 

 not liable to get out of order, inexpensive, and quite effective. 

 Such an apparatus is Warhurst's " Automatic Draught 

 Preventer." 



Mortality statistics show that, in London alone, no fewer 

 than 80 persons annually lose their lives through falling 

 out of wiudows. In the majority of instances, the primary 

 causeof death may be traced to the incaiitious cleansingof the 

 windows. Although it is possible to clean the outer face of the 

 panes of glass in an ordinary window from within the room, 

 it is so excessively awkward a task that the greater number 

 of servants and professional window-cleaners prefer the risk 

 of getting out on to the ledge, and they are thus often over- 

 balanced, and either killed or severely injured. To prevent 

 the possibility of such accidents, the sashes of the window 

 ought to be capable of a wicket, or revolving, as well as a 

 sliding, motion ; these not only serve to enable the operator 

 to clean both the inside and outside of each pane easily 

 without incurring any dangerous risk, but they afford a 



space, when swung open, large enough to allow of the 

 admission of pieces of furniture which are too bulky for 

 removal through doorways and passages. Patent arrange- 

 ments, which incorporate the advantages which we have 

 indicated, and are in addition draught and dust tight and 

 not more expensive than those in general use, are now in 

 the market. Of these, Adams' " Anti- Accident " Window 

 and Penny's " Double- Action " Window-sash and Frame 

 are the most noteworthy. 



The improvements in locks and fastenings for window- 

 sashes, doors, itc, have hitherto been devised chiefly as 

 protective measures against housebreakers. Although they 

 occupy but a subordinate place in the general structure of 

 the house, they are nevertheless well worthy of careful 

 consideration. Burglar-proof sash-fasteners and locks are 

 usually of superior quality and construction, and, as such, 

 secure a firm fastening which prevents rattling, and thereby 

 contributes to the sanitary condition of a house by ex- 

 cluding dust and dirt. In future chapters we shall give 

 examples of the several inventions which illustrate the 

 principles we have here noted, so that our readers may be 

 able to glean beuefits of a practical character from our 

 observations. 



ivfbiehjs;* 



SOME BOOKS ON OUR TABLE. 



EUmentary Text-book of Trigonometry, By R. H. Pin- 

 KERTOX, B.A., Oxon. (London : Blackie & Son.) — For 

 those who have the advantage of a tutor, we have little 

 but praise to give Mr. Pinkerton's little book, treating, as 

 it does, in a lucid form, of plane trigonometry as now 

 taught. One excellent feature is the number of numerical 

 examples supplied in it. It is surprising how much more 

 readily the beginner grasps the meaning of a concrete 

 example than he does that of the formula whence it is 

 derived. Our author's sole innovation, so far as we have 

 been able to detect, lies in the substitution of the word 

 " radian " for what we have hitherto been accustomed to 

 call " circular " measure. The two comparatively trivial 

 faults we have to find with the book are, first, the wasting 

 of more than a page by a description of the " Grade " and 

 its application, this form of measurement being now abso- 

 lutely exploded and disused ; and, secondly, the omission 

 of all reference to arcs iu the description of the trigono- 

 metrical ratios. This is all very well in the case of the 

 student with some preliminary knowledge of the subject, 

 or who has a tutor at his elbow ; but seems too abstract 

 for any one approaching it for the first time. The space 

 wasted on the " Grade " had better have been occupied 

 with the time-honoured circle of our fathers' days. The 

 learner would then have seen to ivhat certain lines were 

 tangents and secants, at all events. 



Charles Daricin. By Edward Woodall. (London : 

 Triibner &. Co.) — This reprint (from the Transactions of the 

 Shropshire Archreological Society) of a succinct biography 

 of one of the (if not the) very greatest and most philo- 

 sophical naturalists the world has ever seen, supplies 

 material for thought to Englishmen of all ages, rousing, as 

 it must do, emulation in the young, far from unmixed 

 sorrow in their seniors, but pride in all. In this record of 

 a noble life we trace the grandson of the author of " Zoij- 

 nomia " and the " Loves of the Plants " ; from his birth 

 at Shrewsbury in 1807, through the Grammar School of 

 that town, the Edinburgh University, and that of Cam- 

 bridge, until, on the recommendation of Professor Henshaw, 

 he was appointed naturalist to the Beaijle expedition to 



