What fascination keeps a busy construction engineer at the hobby of butterfly-collecting for a lifetime? One explanation is a service that Colonel Schroeter was able to perform several years ago for Carroll M. Williams, the eminent Harvard University zoologist who uses insects to study basic life processes. Williams needed a large insect for investigation of metamorphosis and was stymied for lack of supply until he heard about Schroeter and his collection of giant silkworms.

"Our relationship with Colonel Schroeter," writes Williams, "is certainly an excellent illustration of how the amateur can make a distinct contribution to science and share the satisfactions of scientific investigation. The amateur occupies a very special place in entomology because a high proportion of the so-called 'professionals' begin as amateurs. (Later on, incidentally, the complexities of work in a laboratory and an institution may cause them to wish they had remained amateurs!)

"As far as I can judge, Colonel Schroeter was the first to introduce to this country for scientific study and experimentation a wonderful array of 'wild silkworms.' These creatures live in distant parts of the world such as India, Malaya and the slopes of the Himalayas. Colonel Schroeter developed contacts in all these places and has made available to a number of universities and governmental laboratories, including our own, a rich variety of material.

"Certain species of the silkworms have proved strategic for particular types of scientific studies. For example, we have repeatedly called on Colonel Schroeter for specimens of Antheraea mylitta, the so-called giant tussah silkworm of India. This exotic creature is one of the world's largest insects, the full-grown caterpillar weighing about 45 grams. It is easy to see how scientists can use beasts of these proportions to answer chemical and physiological questions which would be quite inaccessible in ordinary insects.

"The Colonel has also made available to us considerable information, derived from his own breeding experiments, concerning the care and feeding of these strange species."

About a year ago many newspapers carried a picture of Schroeter with an 11-inch moth which he had reared from an egg the size of a matchhead. This department sought out the Colonel at his home, and it turned out to be a fascinating visit. Colonel Schroeter explained: "The big fellow is an Attacus edwardsi. As you can see, its wings are various shades of brown and yellow and contain transparent windows. Specimens caught in the Philippine Islands have a wing span of 14 inches. Larvae of the Atlas species of this moth feed on ailanthus leaves-you know, the tree that grows in Brooklyn. My scientist friends have not shown much interest in the Atlas caterpillar even though he is far from being a pigmy. He is green, finger-sized and has blue horns on his head. His body looks as if he's frosted with a sugar coating, and natives say that he is delicious.

"I wish you had made your visit a little later in the year. Then I could have shown you a really big moth, Thysonia aprippina. It is a native of Brazil. Those I have bred have much larger wing spans than the Attacus atlas, which is usually listed as the largest moth in the world. Here is the cocoon of a Thysonia -you can see it is the size of a small sweet potato. You can imagine the proportions of the moth that comes out of it.

"Newspaper reporters make so much fuss over the big fellows that they overlook the really interesting specimens. Take the hybrid luna, for example. Seven years ago an amateur friend of mine in India airmailed to me a dozen cocoons of the Indian moon moth. When the adults emerged some months later, it was evident that they were closely related to the American luna. The two species have about the same shape and size and their wings bear a similar general coloration-a light bluish-green. The wings of the Indian species are distinguished by two patches of red. I decided to try crossing them and finally succeeded last year."

Colonel Schroeter began by acclimatizing the foreign species, which meant breeding several generations of the foreigners here, letting them adapt to local forms of their favorite food plants and to the new environment generally. Then he selected a likely female of the foreign species and mated her with a local male. He has invented a simple gadget to help assure a successful mating. Most amateurs tack a female to a tree by one of her wings and wait for her to attract a mate. "The chief drawback of this technique," says Schroeter, "is that the female's attraction is not limited to mates of her species. When you pin your specimen to a tree you invite predators- other insects, birds and tree toads-to a free dinner. Too often when you come back you find nothing but a pair of wings. Moreover, when you immobilize a single wing the female is apt to thrash around and injure herself. To overcome this difficulty I made what I call a 'mating panel'-a rectangle of Celotex 18 inches long and a foot wide. A screw eye in the center holds a leash of thread, the other end of which is fastened around the female's thorax. With freedom to crawl around on the surface of the panel, she usually quiets down after a few seconds of fluttering. The panel is then suspended by picture wire from the tip of a branch where it is out of the reach of tree toads and free to swing in the breeze. The movement frightens most birds away.

"Moon moths mate at sundown. The next morning the female is transferred to a large paper bag in which she deposits her eggs in two parallel rows. After the eggs have been laid, the bag is cut into little squares, each holding eggs. These are fastened with bits of Scotch tape to the leaves of food plants and surrounded with a bag to prevent the larvae from escaping when the eggs hatch. If you are lucky, the larvae thrive and metamorphosis gets under way. Sometimes the experiment works, but more often it fails. The eggs may be sterile, disease may strike, the food may not be correct. Murphy's law makes no exception of entomology. If anything can go wrong, it will. The failures, however, can be as interesting as the successes, because they pose problems of finding out what went wrong, where and when. In the case of the moon-luna experiment, nature threw the book at me. But in the end I was rewarded with a beautiful hybrid which bore the characteristics of both parents. Its wing markings fade from bright green into greenish-blue and trail through orange to pink at the wing tips. It is probably the only offspring of this combination in the world."

Colonel Schroeter says most lepidoptera mate readily in captivity. Last season he bred more than 5,000 individuals. Eggs come to him from all parts of the world-sometimes in goose quills an other strange containers. Cocoons arrive in balsa boxes from South America and in bamboo cylinders from the Orient. While there is a law against indiscriminate importation of insects into the U. S., the Government has issued to Schroeter a special importing license, subject to strict controls.

"Don't let the import restriction on foreign material keep you out of amateur entomology," he urges. "You can collect domestic species to your heart's content without fear of ever exhausting our known varieties. Reference texts and catalogues list them by the thousands, and scores of new descriptions are added each year.

"You will find caterpillars wherever plants grow. The next time you go for a walk, whether in the park, a meadow or merely in your back yard, take along a paper bag, a piece of string, some note paper and a pencil. When you find a caterpillar, jot down a short description of it-the color, size, markings and such other information as you think will help you recognize the creature when you meet another like it. Make a similar record of the plant on which it was feeding. If you already know the name and nature of the plant, so much the better. Be sure to include the date, approximate time of day and notes on the weather. Then put the bag over the twig or weed on which your specimen is feeding and tie the end closed so it cannot escape. Check up on it a day or so later. You will likely discover that the leaves have been eaten. If so, shift everything to a fresh batch of leaves. You may have to repeat this several times.

"Eventually you will find that your specimen has vanished and a cocoon has taken its place. With luck you may catch the caterpillar in the act of spinning its cocoon. Make full notes of its methods and how long a time it spends in the process. When the cocoon is complete, break off the twig to which it is attached and transfer operations to a small cage, which you can make of window screening. Place the cage outdoors in a location matching as closely as possible that where you found the insect. Some species prefer sunny locations; others do best in shade. After days or weeks-depending upon the species and the season of the year-the adult will emerge, and you will have the thrill of discovering the exotic creature your caterpillar was destined to become."

By starting with the caterpillar instead of with the butterfly, Colonel Schroeter explains, you learn to recognize at first hand three of the four stages in the life cycle of your insect-larva, pupa and adult. Your notes now give purpose to your future field trips. You hunt for another caterpillar and cocoon of the same species. With luck you may even come across an adult female in the act of laying her eggs. When they have been mounted and labeled, you have the complete life cycle of the insect and the beginning of a collection of scientific value. Although thousands of adult moths and butterflies have been catalogued, the life cycle of a majority of those in nature still awaits description- an ideal project for the amateur who enjoys original work.

"One attractive feature of amateur entomology," says Schroeter, "is the fact that you never run out of interesting projects for your spare hours. Collecting and breeding are merely two facets of the hobby's many sides. For convenience in study, collections must be mounted and labeled. This can be an absorbing pastime the year around. Only the most perfect specimens are selected for mounting. They are killed and stored against the day when bad weather forces you to remain indoors.

"You first stun the insect by pinching the lower side of the thorax lightly between your thumb and index fingers. The thorax is the part of the body, directly back of the head, to which the wings are attached. Stunning is necessary to prevent the insect from fluttering and damaging itself when you drop it into the killing jar. The jar can be any wide-mouthed container with a tight-fitting cover. A layer of absorbent material, such as plaster of Paris, is placed in the bottom and saturated with a tablespoon of Carbona. Some amateurs prefer poisons such as potassium cyanide, but they are dangerous and unnecessary. The dead specimen is stored in a triangular envelope. The envelopes are numbered to correspond with the entries in your notebook."

In about a week the dead insects become hard and brittle. They must be "relaxed" or softened before mounting. You put the dried insects into a jar containing a rubber sponge or other absorbent moistened with water to which a few drops of carbolic acid have been added. The acid prevents the formation of mold or other microorganisms. A couple of blotters placed between the insects and the sponge will prevent them from getting too wet. After two or three days they are ready for mounting.

The sketch above illustrates the details of the procedure. A convenient outfit for mounting consists of a spreading board, two slender strips of glass, tweezers, scissors, pins and a sup- e ply of thin cardboard. A spreading board is easily made from balsa or Celotex, with a groove in the center for the body of the insect. The slight upward slant of the board on each side of the groove makes allowance for the tendency of the wings to droop as they age. Mounting outfits can be bought from a supply house; the Butterfly Art Jewelry, Inc., of 289 East 98th St., Brooklyn, N.Y., for example, lists a kit including spreading board, forceps, pins, a display case and other essentials plus 10 tropical butterflies for practice mounting. Similar materials are available from the Standard Scientific Supply Corp., 36 West 4th Street, New York, N. Y.

To mount the specimen you grasp it by the lower side of the thorax, part the wings by blowing lightly, and thrust a pin through the thorax from the top. The pin should be inserted into the insect just far enough to bring the point of wing attachment level with the surface of the spreading board when the pin has been forced into the bottom of the groove. Then blow the wings apart again and place the specimen on the board, weighting down the wings with strips of glass. Each glass is lifted in turn just enough to permit pulling the forewings forward by means of a pin inserted behind one of the heavy veins. When the trailing edge of the forewing makes a right angle with the axis of the body, it is pinned down with strips of cardboard as shown. Wider strips of cardboard are then pinned in place of the glass weights. The specimens will be dry enough in about a week for transfer to the display case.

Eggs and pupae are mounted without special preparation. Cement the eggs to paper strips of contrasting color. Pin the pupa as though it were a dried adult. A larva must be degutted and inflated before mounting. After killing, place the larva on a square of blotting paper and, with a fine scalpel, enlarge the anal orifice slightly. Then, beginning at the head, squeeze the viscera out by rolling a pencil down the body. The carcass is restored to normal shape by inflating it with a syringe, which you can make yourself. Heat a section of quarter-inch glass tubing to a dull red and quickly draw one end into a fine nozzle, somewhat thinner than the small end of a medicine dropper. Fit the large end with a rubber bulb. You then inflate the larva by inserting the nozzle into its anal opening and squeezing the bulb sharply. The anal opening is closed with a bit of Scotch tape until the tissues harden.

For convenience in subsequent study, specimens are generally pinned to the bottom of a glass-topped display tray. Many arrange the eggs, larva, pupa and adult of each species as a group. Among the catalogues compiled to aid the beginner in identifying his specimens are The Butterfly Book and The Moth Book, by W. J. Holland.

Colonel Schroeter recently gave his entire collection of thousands of specimens to the University of Connecticut. J. A. Manter, the University's zoologist, writes: "The Schroeter collection is the most colorful that I have ever seen. Every division of world macrolepidoptera is represented by rare specimens, and it is especially remarkable because of their excellent condition. Such a collection is often spoken of as an 'Oh, my!' one-the reaction it evokes from visitors as the trays are successively pulled into view. Colonel Schroeter's devotion to amateur entomology has resulted in a lasting contribution to science from which future generations of students will derive both knowledge and enjoyment."

The late William Morton Wheeler, the great Harvard entomologist, once summed up the joys of the amateur in these words: "We should realize, like the amateur, that the organic world is also an inexhaustible source of spiritual and esthetic delight. Especially in college we are unfaithful to our trust if we allow biology to become a colorless, aridly scientific discipline devoid of living contact with the humanities. We should all be happier if we were less completely obsessed by problems and somewhat more accessible to the esthetic and emotional appeal of our materials. It is doubtful whether, in the end, the growth of biological science would be appreciably retarded. It quite saddens me to think that when I cross the Styx, I may find myself among so many professional biologists, condemned to keep on trying to solve problems, and that Pluto, or whoever is in charge down there now, may condemn me to sit forever trying to identify specimens from my own diagnoses while amateur entomologists, who have not been damned professors, are permitted to roam at will among the fragrant Elysian meadows netting gorgeous, ghostly butterflies until the end of time."

A sundial, if it is to be accurate, must be designed uniquely for its latitude and longitude. Ready-made sundials are merely. attractive bird perches, useless for precise time-telling, because the manufacturers can design only for an average location. Hence anyone who wants a scientific dial must build his own. Sundialing is fascinating fun, and it takes only an hour or two to bone up on the irregularities in the earth's motion -the "equation of time"-that affect a dial. You can get the necessary information from a textbook on elementary astronomy or from Sundials-How to Know, Use and Make Them, by R. Newton Mayall and Margaret L. Mayall.

In the September, 1953, issue we published descriptions of several scientific sundials built by readers. Here are some others received since then.

The first [upper drawing on the left] was made by H. M. McNair of Scotland. He says: "My dial has a circular scale with five-minute divisions inked on the upper side of a disk of glass within a ring of polished metal. When the ring is adjusted so that the glass is parallel to the equatorial plane, the sun's reflection from the inside of the ring forms a cusp of light which is visible on the glass because the glass is finely ground on its lower side. This cusp which indicates the time, travels around the circular scale at a uniform rate for any one day. (The dial will also show the moon's angle.) The equation of time is taken care of by a scale of minutes by which the glass may be slightly rotated and set to a datum mark. The dial has to be adjusted every few days. I adjust the ring parallel to the equatorial plane by supporting it at a notch diametrically opposite the datum mark, on a knife-edge adjustable for height. The height of the knife-edge above the baseboard should equal the cosine of the latitude times the outside diameter of the ring. The lower rim rests on the surface of the baseboard and, after swinging a little, settles to its required position.

"The dial is easily moved and set up. Its one drawback is that for about two days at the equinoxes, when sunlight comes in parallel to the ring, there is no cusp and the timepiece fails."

Jean Haegel, of Paris, has built an equatorial dial [lower drawing] which automatically corrects the irregularities of the earth's motion. On many sundials the irregularities are represented by a curve in the shape of the figure 8, called an analemma. On Haegel's dial the gnomon, the part that indicates the time by casting a shadow, is a spindle in the analemma shape. Haegel writes: "This still makes one approximation necessary: the equation of time has to be made symmetrical with respect to the solstices. But I hasten to say that the small error thus accepted is just about covered by the one weakness of this design: the reading is taken on the edge of the shadow and this edge is not too well defined. One must also remember on which side of the shadow to read the time; a good watch helps!"

Sundialing is so ancient a craft that rarely is a really new principle discovered. Mayall and Mayall, the authors of the sundial book, comment that a dial like Haegel's was made in Europe about 1850 and patented in the U. S. about 1900. Nevertheless the Haegel idea will be new to most amateurs. Haegel himself remarks: "The news that my dial is at least a century old makes me feel better. I felt rather queer before."

In 1925 F. Hope-Jones of England published in the British periodical Engineering a description of a mechanical "sun clock" invented by W. E. Cooke of the Sydney Observatory in Australia. The hands of a conventional clock were geared to a large ring with a small hole on its sunward side. An analemma was placed below. To read the time by the hands of the clock you turned the ring until the sunbeam through the hole bisected the curve of the analemma. Russell W. Porter made one of these sun clocks and introduced them to sundialists in this country through SCIENTIFIC AMERICAN (August, 1928, and August, 1935). Porter built 19 sundials and sun clocks; his dooryard was full of them.

As a variation on the original theme Porter mounted one sun clock in a movable, spherical Pyrex flask, omitting the clock hands. Without knowing about the source of this variation, Neal M. Kohler and fellow employees of the Titan Metal Manufacturing Company in Bellefonte, Pa., recently redesigned the flask theme and came out with the sundial illustrated by the upper drawing on the right. The Titan Company makes brass and bronze products, and its employees know how to make these metals really sing. This is proved by photographs and by the detailed blueprints which are not shown here.

In 1952 Thomas C. Rathbone, a Brooklyn engineer, again without knowing of Porter's series of clocks but working directly from descriptions of Cooke's original sun clock in Australia, designed the rugged and attractive instrument illustrated in the lower drawing in Figure 4. This one has an hour circle eight inches in diameter. Rathbone has made another which uses three large wagon tires and is capable of telling time within 15 seconds if the graduations for a low sun are adjusted for refraction.

The fact that all these sun clocks have a family resemblance does not prove either telepathy or burglary; it simply suggests that all sundials have ultimately the same designers-the sun and the earth. Form follows function.

For three decades six inches has been the standard size of the amateur telescope maker's first try at building a reflector. Now there is a trend toward beginning at four and a quarter inches, the next smaller size in Pyrex disks. Theoretically a 4 1/4-inch telescope is only two fifths as big as a six-inch, while its power is two thirds as great. A growing number of advanced amateurs who have built larger instruments are adding a 4 1/4-inch to their menagerie because the smaller size is more manageable and portable.

A 16-inch telescope is 22 times as heavy, bulky and costly as a six-inch. This may explain why so little came of the hundreds of 16-inch war-surplus Pyrex disks that eager amateurs bought six years ago when a die manufacturer offered them for only $12.50 each (the Corning price for that size is $107.50). Purchased in haste because of the bargain, most of these were repented at leisure when the sobering realities of geometry were thought out. The owners still hold them in hope.

Bibliography

BUTTERFLY AND MOTH BOOK. Ellen Roberson-Miller. Scribner's Sons, 1931.

Suppliers and Organizations

The Society for Amateur Scientists
5600 Post Road, #114-341
East Greenwich, RI 02818
Phone: 1-401-823-7800

Internet: http://www.sas.org/