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always an easy matter. Authors have called attention to the broader wings of the butterflies as distinguished from the narrow and sharper ones of the moths. The manner of folding the wings on alighting has been suggested as a means of separating the two. The surest mode however, of arriving at a correct determination is by a study of the antennæ. In the diurnals these will be found to be either knobbed or hooked at the end, while in the nocturnals the antennæ are either filiform or pectinate. In the pupa state the diurnals are readily distinguished, as the pupa case is more or less angulated, and often ornamented with silvery or golden spots, whence the name of chrysalis.*

The scientific arrangement of the families of this order is a matter about which lepidopterists uniformly disagree. The family Papilionidæ is by some made to embrace all the diurnals. Others limit it mainly to the so called swallow tails, or those large butterflies which have a tail like appendage to each of the hind wings. In this family are arranged also the small white cabbage butterflies, belonging to the genus Pieris, and the numerous sulphur yellow ones, belonging to the genera Colias and Terias.

The Nymphalidæ embrace many of our most common butterflies. The hind wings are broad and either rounded or deeply escalloped. These are the numerous red and black butterflies with which everyone is familiar. The most extensive genus is perhaps Argynnis which comprises about fifty species. In other genera as in Satyrus and its allies the colors deepen more and more until a dark brown or black is reached.

The Lycaenidæ and the Hesperido embrace nearly two hundred and fifty species of butterflies whose average spread of wing perhaps will not exceed one inch. They vary greatly in color, some of the genera of the former being distinguished by slight projections from the hinder wings which in miniature suggest the Papilionida.

The Hesperidæ are peculiar in having the ends of antenna hooked rather than knobbed. They are known in England as hook-tips, in America more often as skippers. Their swift and bat-like flight, as they are startled from the flowers or leaves on which they have alighted for repose, well suggests the propriety of the latter name.

0. S. WESTCOTT.

។

To be continued.

* cf. Chrysostom, chrysoprase etc.

LABOR and brains conquer all things.

SELECTED.

SCHOOL BUILDINGS.-II.

THE ARRANGEMENT OF ROOMS

should be such as will enable the teacher to exercise due supervision without too great a strain upon the nervous system; in the large majority of cases this point receives little, if any, attention. In a room intended to accommodate forty-five pupils — and no larger number should ever be under the charge of any single teacher - having at least 900 feet of square feet of floor surface devoted to the pupils, and an additional space of about fifty square feet for the teacher's dais, the figure of an exact square is the worst; a parallelogram measuring 26x37 feet is probably as good a form as any, and the teacher's platform should be placed on one of the longer sides, preferably on the same side with the windows, the black-boards being opposite. Nor do we deem it necessary for the pupils to sit facing the teacher's position; let their desks be so placed that the light shall fall upon them, as we have said, from above, and the left hand, even though this should involve the absolute reversal of the usual arrangement of the school room, and seat the students with their back toward the dais. And, let us say in passing, that this is by no means a new or untried plan; more than twenty years ago we were engaged in a large military academy on the banks of the Hudson river, New York, in which the peculiar arrangement of seats and desks above referred to was carried out and found to work admirably; we have never been engaged in a school room in which good order was more easily maintained.

All doors should be so hung as to open outwards, and should be of sufficient width to allow of two persons passing through them at the same time without crowding or inconvenience. Provision should also be made by which doors can be readily lifted from their hinges in case of need, thus leaving the doorway free from any possible obstruction.

SEPARATE WATER CLOSETS, or privies, must be provided for pupils of either sex, and when they are placed out of doors they must be connected by means of covered ways with the main building, and properly screened; protection from the weather by covered ways is indispensable in closets for girls and young children of both sexes.

It is probable that there are few, if any, physicians in the state who

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cannot point to one or more cases of serious disease in females brought on by delaying as long as possible to obey the calls of nature, by reason of a natural reluctance to encounter the discomfort and exposure to cold attendant upon a visit to the privy as that building is usually constructed. As the health of our children, and especially of the mothers of future generations is concerned, it becomes an imperative duty to call attention to this fact. Not only should the privy and its approaches be well protected from the weather, but especial care must be taken to keep them dry, clean and well ventilated; if they are placed within the main building - and that situation has important advantages as well as serious drawbacks — they must be well lighted, warmed and ventilated by an outward current of air.

The best arrangement that probably can be made, especially in cities with a good water supply, is to build a special tower for the water closets, as is recommended by Mr. Eassie; such a tower should be at once connected with and shut off from the main building by a short passage provided with doors at both ends; both closets and passages in this case being furnished with ventilating shafts which must. be carried up to the highest point of the building.

Privies should be sufficiently large, and those for boys' use must be provided with urinals of slate or other impervious material. Care must also be taken that all privies and water closets are so arranged as to afford no opportunity for the practice of solitary vices or any other form of licentiousness. Special accommodations should be made for the use of the youngest children. Under no circumstances should any closet be placed under any study or recitation room.

We have spoken at some length of the proper structure and keeping of water closets and privies, because we believe that it is very rare for any matter of such prime necessity to be so generally overlooked and neglected. Our experience of a quarter of a century as a teacher in schools of all grades and in many parts of the United States, has shown us that properly built and decently kept privies in connection with schools are rarely, if ever, to be found. They are often too filthy for any decent boy or girl to approach, and hence the important act of defecation is postponed, and health seriously if not irreparably injured. There is the most urgent need of a thorough reform in this respect.

VENTILATION

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must be sufficient to furnish at least 500 cubic feet per hour of pure, warm air to every occupant of every room.

For entries, passages, etc., from one-half to two-thirds of this amount is sufficient; for hat and cloak closets quite as much is needed as for recitation and study rooms, and in these, as in water closets, the current should be directly outward to the

open

air never by any chance into an entry or, still worse, into an occupied room. Ventilation of cloak rooms, water elosets, etc., by means of outer windows is not to be recommended, for the reason that snow and rain may easily enter by them; the use of a sufficiently large air-tube as above recommended is, perhaps, as free from objection as any other method.

HEATING

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in a large building is best and most economically accomplished by one large central furnace, which ought also to be made a powerful auxiliary to proper ventilation. There is a singular diversity of opinion among those who have given most attention to the subject, as to where and how the warm air should be introduced into a room. The plan (proposed by Mr. L. W. Leeds) of warming the walls and floors seems among the best of those proposed, but we have no knowledge of its having been practically tested upon a large scale. The Ruttan system of warming and ventilating seems also to promise excellent results.

Heating by means of steam-coils or other radiators is among the most defective of methods, for the reason that heating only is thus provided for, and the renewal of the air is wholly neglected. When furnaces are used the registers for the admission of warm air should be sufficiently large, as should also the shafts that supply them; the registers placed in the barracks of the British army are required to have an area of ten square inches for each person occupying a room, and the shafts which supply them an equal cross section; if shafts and registers be much smaller than this, the proper heating of the various apartments will require the rapid entrance of a current of air at a very high temperature instead of a gentle current, not warmer than 70° Fah.

The large majority of our school rooms, unfortunately, are heated by means of stoves, one of which is provided for every room in a building; thermometers are almost unknown, and the windows afford the only means of ventilation; these are opened and shut as the teacher, seated at her desk frequently close to the stove, happens to feel uncomfortably warm or cold. Cloak closets, where these are found, are seldom, if ever, provided with any proper means of warmth or ventilation, and the odor, too easily perceptible in them, of "old boots, dirty clothes and perspiration," is foul beyond description. In small buildings the heating apparatus may be a stove of sufficient size placed in a proper chamber in the cellar; there should be a shaft connecting this chamber with the outer air, and a register of sufficient size communicating with the school room above. Care being taken that the fresh air trunk is kept open for the entrance of air, and closed to rats or other vermin, a sufficiently warm temperature may be always secured with moderate attention.

If stoves are used in school rooms, no device in shape of a "damper” should be allowed in the pipes, nor should any means whatever of lessening or obstructing the caliber of the pipes or chimney-flues be tolerated under any circumstances; the draught can be regulated by proper valves in the front of the stove.

HAT AND CLOAK ROOMS

should be attached to all school rooms, and be provided with proper pegs or hooks, placed at such heights from the floor as will enable those for whose use they are intended to reach them without undue effort. As has already been said, such closets should be properly lighted, warmed and ventilated, and some means should also be adopted by which damp or wet shoes and out-door wrappings can be properly dried in stormy weather; space for this purpose can generally be found in the basements of our larger school houses.

DRAINS

must be secured from injury by rats and other vermin by means of grated outlets and proper care in the first construction. Special care must be had lest the water for drinking purposes becomes fouled by leakage from them.

WATER SUPPLY.

In cities furnished with a good system of water supply the pipes. should be led into the building, care being taken to protect them from frost. In other localities water should be drawn from the purest accessible source. School authorities are usually too easily satisfied in this most important matter, with doing the thing that can be done with least trouble and expense. “Great vigilance should be main

' tained to see that, under no circumstances, does the wash from the privy or sink work into the well, as it may do when least suspected by indirect and hidden channels, or by surface drainage, with the